WO2024087164A1

WO2024087164A1 - Overcurrent protection method and system for energy storage valve, computer device, and storage medium

Info

Publication number: WO2024087164A1
Application number: PCT/CN2022/128223
Authority: WO
Inventors: 卢艳华; 余东旭
Original assignee: 宁德时代未来能源(上海)研究院有限公司
Priority date: 2022-10-28
Filing date: 2022-10-28
Publication date: 2024-05-02

Abstract

The present application relates to an overcurrent protection method and system for an energy storage valve, a computer device, a storage medium, and a computer program product. The method comprises: acquiring real-time operation parameters of a bridge arm of a converter, wherein the real-time operation parameters at least comprise a real-time bridge arm current value and a duration of the real-time bridge arm current value; if the real-time operation parameters of the bridge arm of the converter meet a bridge arm permanent locking condition of permanent overcurrent protection, generating a permanent overcurrent protection signal, and sending the permanent overcurrent protection signal to a logic determination unit for determination; and if a determination result is that permanent overcurrent occurs in the bridge arm of the converter, carrying out bridge arm permanent locking on the bridge arm of the converter. The method can improve the reliability of overcurrent protection.

Description

Overcurrent protection method, system, computer equipment and storage medium for energy storage valve

Technical Field

The present application relates to the technical field of power system energy storage, and in particular to an overcurrent protection method, system, computer equipment, storage medium and computer program product for an energy storage valve.

Background technique

In the current energy storage system, PCS (energy storage inverter) and energy storage battery are independent of each other. Multiple PCSs connected in parallel are prone to oscillation. The two-level/three-level PCS power conversion efficiency is low. A large number of batteries connected in series and parallel require the BMS (Battery Management System) to have strong battery management capabilities. There are also problems such as three-phase imbalance in the distribution network and line overload/underload.

With the development of new energy technologies, new energy storage systems have emerged that can achieve flexible regulation of the output power of the energy storage system and optimize the battery pack management capabilities. At the same time, they can eliminate grid-connected harmonics, reduce costs, reduce the DC voltage that the battery withstands and the BMS's requirements for the battery management capabilities. The system network loss is lower and the operation reliability is higher.

The new energy storage valve control system is the core control device of the new energy storage system. However, the protection method of the new energy storage system is to protect through the locking and tripping of temporary overcurrent protection. The protection method is single and the reliability is low.

Summary of the invention

In view of the above problems, the present application provides an overcurrent protection method, system, computer device, storage medium and computer program product for an energy storage valve, which can solve the problems of temporary overcurrent protection locking and tripping for overcurrent protection, single overcurrent protection and low reliability.

In a first aspect, the present application provides an overcurrent protection method for an energy storage valve. The method comprises:

Acquire the real-time operating parameters of the bridge arm of the converter; the real-time operating parameters at least include the real-time bridge arm current value and the duration of the real-time bridge arm current value;

If the real-time operating parameters of the bridge arm of the converter meet the permanent arm permanent locking condition of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment;

If the judgment result is that the bridge arm of the converter is permanently overcurrent, the bridge arm of the converter is permanently locked.

In the above embodiment, when the bridge arm of the converter is released from temporary locking, the operating parameters of the converter are detected in real time to perform overcurrent protection. When it is detected in real time that the real-time bridge arm current value and the duration of the converter meet the permanent locking condition of the bridge arm for permanent overcurrent protection, the bridge arm of the converter is permanently locked by sending the permanent overcurrent protection signal to the logic judgment unit. When the permanent locking condition of the bridge arm for permanent overcurrent protection is met, the bridge arm is locked to perform overcurrent protection on the corresponding bridge arm of the converter, instead of directly locking the entire converter and jumping the line switch. The overcurrent protection of the converter is segmented, thereby improving the reliability of the overcurrent protection.

In one of the embodiments, before obtaining the operating parameters of the bridge arm of the converter, the method further includes:

Acquire a first operating parameter of a bridge arm of the converter;

If the first operating parameter meets the temporary over-current protection start condition, a temporary over-current protection signal is generated;

Temporarily blocking the bridge arm of the converter based on the temporary overcurrent protection signal, and recording the number of temporary blocking times of the bridge arm of the converter;

Acquire a second operating parameter of the bridge arm of the converter;

If the second operating parameter satisfies the overcurrent protection release condition, generating an overcurrent protection release signal;

The bridge arm of the converter is unlocked based on the overcurrent protection release signal.

In the above embodiment, when the bridge arm of the converter is temporarily overcurrented, the lock is performed, and by further determining whether the overcurrent protection is released, the temporary lock is unlocked to avoid the temporary lock directly tripping the line switch, causing the entire station to stop operating.

In one embodiment, the first operating parameter includes a first bridge arm current value and a duration of the first bridge arm current value, and if the first operating parameter satisfies a temporary overcurrent protection start condition, generating a temporary overcurrent protection signal includes:

If at least two valve protection units detect that the corresponding first bridge arm current value is greater than the first set current of temporary overcurrent protection, and the overcurrent duration of the first bridge arm current value is greater than the first set duration of the temporary overcurrent protection, at least two candidate temporary overcurrent protection signals are generated;

At least two of the candidate temporary over-current protection signals are sent to a logic judgment unit, and the logic judgment unit makes a judgment based on the at least two temporary over-current protection signals to generate a temporary over-current protection signal.

In the above embodiment, when the converter bridge arm is in a temporary overcurrent state, at least two valve protection units are used for detection to generate at least two candidate temporary overcurrent protection signals. The logic judgment unit judges the at least two candidate temporary overcurrent protection signals to generate a temporary overcurrent protection signal, thereby improving the reliability of the temporary overcurrent protection.

In one embodiment, temporarily blocking the bridge arm of the converter based on the temporary overcurrent protection signal includes:

The temporary over-current protection signal is sent to the valve control unit, and the bridge arm of the converter is temporarily locked by the valve control unit.

In the above embodiment, temporary blocking is directly performed on the valve control unit side according to the temporary over-current protection signal sent upward, thereby improving data processing performance and reliability.

In one of the embodiments, the first set current has a value range of 1.2 to 2.0 rated current values, and the first set duration has a value range of 0 to 500 us.

In one embodiment, the first set current is greater than the second set current, the first set time is less than the second set time, the second set current has a value range of 0 to 1.0 rated current value, and the second set time has a value range of 0us to 3000us.

In the above embodiment, by considering the temporary overcurrent of the energy storage valve control system and the autonomous recovery of the temporary overcurrent, the set current and duration of the temporary overcurrent lockout, as well as the set current and duration of the unlocking are set, thereby ensuring the stability and safety of the energy storage valve control system.

In one embodiment, the real-time operating parameters further include the number of temporary blocking times. If the real-time operating parameters of the bridge arm of the converter meet the permanent blocking condition of the bridge arm of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, including:

If it is detected that the temporary blocking times are greater than a set threshold, a permanent over-current protection signal is generated.

In the above embodiment, in the case of unlocking after temporary blocking, by counting the number of temporary blocking times, when the number of temporary blocking times is greater than the set threshold, a permanent overcurrent protection signal is generated. By performing segmented overcurrent protection on the converter bridge arm, the overcurrent protection method is increased, thereby improving the reliability of the overcurrent protection.

When the number of temporary lockouts is less than a set threshold, if the real-time bridge arm current value and the duration meet the bridge arm permanent lockout condition of permanent overcurrent protection, a permanent overcurrent protection signal is generated.

In the above embodiment, when temporarily locked and then unlocked, after the time limit and the set value are extended and the requirements of the set value and the time limit are met, a permanent overcurrent protection signal of the single bridge arm is generated, and then the bridge arm current converter valve plays a protective role, increasing the overcurrent protection mode and improving the reliability of the overcurrent protection.

In one embodiment, if the real-time operating parameters of the bridge arm of the converter meet the permanent arm permanent locking condition of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment, including:

If the real-time bridge arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection, a permanent overcurrent protection signal is generated and sent to the logic judgment unit for judgment.

In the above embodiment, in the case of unlocking after temporary locking, after the time limit and the set value are extended and the requirements of the set value and the time limit are met, the converter is controlled by a permanent overcurrent protection signal to perform a single bridge arm permanent valve lock, and then the bridge arm converter valve plays a protective role, increasing the overcurrent protection method and improving the reliability of the overcurrent protection.

In one embodiment, if the real-time bridge arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment, including:

If at least two valve protection units detect that the corresponding real-time bridge arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection, at least two candidate permanent overcurrent protection signals are generated;

Sending at least two of the candidate permanent over-current protection signals to a logic judgment unit, and the logic judgment unit makes a judgment based on the at least two candidate permanent over-current protection signals;

If at least one of the candidate permanent overcurrent protection signals indicates that the bridge arm of the converter is permanently overcurrent, it is determined that the bridge arm of the converter is permanently overcurrent.

In the above embodiment, when temporarily locked and then unlocked, the time limit and the set value are extended, and after the valve protection unit is further tested to meet the requirements of the set value and the time limit, the candidate permanent overcurrent protection signals of multiple valve protection units are judged by the logic judgment unit to generate a permanent overcurrent protection signal, thereby ensuring the reliability of the permanent overcurrent protection signal.

In one embodiment, if the bridge arm of the converter is permanently overcurrented, the bridge arm of the converter is permanently locked, including:

The permanent overcurrent protection signal is sent to the valve control unit, and the bridge arm of the converter is permanently locked by the valve control unit.

In the above embodiment, temporary blocking is directly performed on the valve control unit side according to the permanent overcurrent protection signal sent upward, thereby improving data processing performance and reliability.

In one embodiment, the third set current value ranges from 1.5 to 2.0 of the rated current value, and the third set time value ranges from 0us to 1000us. By setting the set current value and time limit of permanent overcurrent protection, permanent overcurrent protection is performed.

In one embodiment, the method further comprises:

If it is detected that all bridge arms of the converter are not in the state of permanent arm locking, obtaining a third operating parameter of the bridge arm of the converter in the state of permanent arm locking; the third operating parameter includes a third bridge arm current value of the bridge arm of the converter and a duration of the third bridge arm current value;

If the third operating parameter satisfies the permanent overcurrent protection condition of the entire bridge arm, the entire converter is locked and the line switch is tripped.

In the above embodiment, by detecting that all bridge arms of the converter are not in the permanent lock state, further detection of the converter is performed to lock and shut down all bridge arms, and at the same time, an application is made to trip the incoming line switch, thereby avoiding the impact of the accident scope on the system and improving the safety and stability of the system.

In one embodiment, if the third operating parameter satisfies the permanent overcurrent protection condition of the whole bridge arm, the entire converter is locked and the line switch is tripped, including:

If the logic judgment unit or the valve control unit detects that the current value of the third bridge arm is greater than the fourth set current of the permanent overcurrent protection of the full bridge arm and the duration of the current value of the third bridge arm is greater than the fourth set duration of the permanent overcurrent protection of the full bridge arm, the entire converter is locked and the line switch is jumped.

In the above embodiment, the permanent overcurrent protection of the whole bridge arm of the converter is judged on the logic judgment unit or the valve control unit side, which improves the overcurrent protection method and improves the reliability of the converter overcurrent protection.

In one of the embodiments, the fourth set current value ranges from 2.0 to 3.0 of the rated current value, and the fourth set time value ranges from 0us to 1000us.

In the above embodiment, by setting the set current and duration of the permanent overcurrent protection of the entire bridge arm, the impact on the system caused by the expansion of the accident scope is avoided.

In a second aspect, the present application provides an overcurrent protection system for an energy storage valve. The system includes a valve control module, an overcurrent detection module and a logic judgment module, wherein:

The overcurrent detection module is used to perform overcurrent detection on the real-time operating parameters of the bridge arm of the converter; if it is detected that the real-time operating parameters meet the permanent locking condition of the bridge arm of the permanent overcurrent protection of the valve control module, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment module;

The logic judgment module is used to judge the received permanent over-current protection signal to obtain a judgment result; if the judgment result is that the bridge arm is permanently over-current, the permanent over-current protection signal is sent to the valve control module;

The valve control module is used to respond to the permanent overcurrent protection signal and permanently lock the bridge arm of the converter.

In a third aspect, the present application further provides a computer device. The computer device includes a memory and a processor, the memory stores a computer program, and the processor implements the following steps when executing the computer program:

Acquire real-time operating parameters of the bridge arm of the converter; the real-time operating parameters at least include a real-time bridge arm current value and a duration of the real-time bridge arm current value;

If the judgment result is that the bridge arm of the converter is permanently overcurrent, the bridge arm of the converter is permanently locked. In a fourth aspect, the present application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the following steps are implemented:

If the judgment result is that the bridge arm of the converter is permanently overcurrent, the bridge arm of the converter is permanently locked. In a fifth aspect, the present application also provides a computer program product. The computer program product includes a computer program, and when the computer program is executed by a processor, the following steps are implemented:

If the judgment result is that the bridge arm of the converter is permanently overcurrent, the bridge arm of the converter is permanently locked. The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below.

BRIEF DESCRIPTION OF THE DRAWINGS

Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

FIG1 is an application environment diagram of an overcurrent protection method for an energy storage valve in one embodiment;

FIG2 is a schematic flow chart of an overcurrent protection method for an energy storage valve in one embodiment;

FIG3 is a current schematic diagram of overcurrent protection in one embodiment;

FIG4 is a schematic flow chart of a method for temporary overcurrent protection in one embodiment;

FIG5 is a schematic diagram of steps of a method for temporary overcurrent protection in another embodiment;

FIG6 is a schematic flow chart of an overcurrent protection method for an energy storage valve in another embodiment;

FIG7 is a schematic flow chart of the steps of permanent overcurrent protection in one embodiment;

FIG8 is a schematic flow chart of an overcurrent protection method for an energy storage valve in another embodiment;

FIG9 is a schematic diagram of data interaction of an overcurrent protection method for an energy storage valve in one embodiment;

FIG10 is a schematic structural diagram of an overcurrent protection system for an energy storage valve in one embodiment;

FIG. 11 is a diagram showing the internal structure of a computer device in one embodiment.

Detailed ways

The following embodiments of the technical solution of the present application will be described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technical personnel in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character "/" in this article generally indicates that the associated objects before and after are in an "or" relationship.

In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

With the development of new energy technologies, energy storage systems are one of the more important research directions in the field of new energy. New energy storage systems can realize flexible regulation of energy storage system output power, optimize battery pack management capabilities, etc. New energy storage systems, for example, high-voltage direct-mounted energy storage systems in high-voltage grid application scenarios. The energy storage valve control system is the core control device of the energy storage system, and valve-controlled overcurrent detection is the key to the stable operation of the entire flexible DC converter valve. The overcurrent protection method currently used is to perform overcurrent protection through the locking and tripping of temporary overcurrent protection. The overcurrent protection is single and has low reliability.

In order to solve this technical problem, an overcurrent protection method for an energy storage valve is proposed, which is applied in the application environment shown in FIG1, wherein the energy storage valve can be, but is not limited to, a high-voltage DC direct-mounted energy storage valve, an AC direct-mounted energy storage valve, an MMC energy storage valve, etc. The application environment shown in FIG1 includes a valve control host A and a valve control host B, a logic judgment device A and a logic judgment device B, an overcurrent detection device A, an overcurrent detection device B and an overcurrent detection device C, a measuring unit A, a measuring unit B, and a measuring unit C. The valve control host A and the valve control host B are mutually redundant, and the logic judgment device A and the logic judgment device B are mutually redundant. The overcurrent detection device detects the real-time operating parameters of the bridge arm of the converter measured by the measuring unit; wherein the real-time operating parameters at least include the real-time bridge arm current value and the duration of the real-time bridge arm current value; when the overcurrent detection device detects that the real-time operating parameters of the bridge arm of the converter meet the permanent arm permanent locking condition of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment device for judgment; if the judgment result is that the bridge arm of the converter is permanently overcurrent, the bridge arm of the converter is permanently locked through the valve control host. By segmenting the overcurrent protection of the converter, when the real-time bridge arm current value and duration of the converter are detected in real time to meet the permanent arm permanent locking condition of the permanent overcurrent protection, the corresponding bridge arm of the converter is permanently locked. On the basis of considering the overcurrent protection, the overcurrent protection mode is further improved, avoiding a single form of overcurrent protection, and improving the reliability of the overcurrent protection.

It can be understood that temporary overcurrent protection can be understood as overcurrent stage I protection; permanent overcurrent protection, that is, single bridge arm permanent overcurrent protection can be understood as overcurrent stage II protection; full bridge arm permanent overcurrent protection can be understood as overcurrent stage III protection.

In one embodiment, as shown in FIG2 , an overcurrent protection method for an energy storage valve is provided, which is described by taking the application environment in FIG1 as an example, and includes the following steps:

Step 202: acquiring real-time operating parameters of the bridge arm of the converter, wherein the real-time operating parameters at least include a real-time bridge arm current value and a duration of the real-time bridge arm current value.

The converter includes at least one bridge arm, each bridge arm corresponds to an overcurrent protection, and a CT coil is added at the head end or tail end of the bridge arm to detect and protect the current on the bridge arm. The overcurrent protection plays the role of protecting the energy storage valve. When the overcurrent protection action (or the overcurrent protection working signal or the overcurrent protection signal) occurs, the energy storage valve submodule is locked, and the tripping signal is sent up at the same time. The final judgment signal is obtained through logical judgment and sent to the valve control unit to lock the energy storage valve and request the branch tripping signal at the same time. In this embodiment, a bridge arm of the converter is taken as an example for explanation.

The real-time bridge arm current value can be measured by a measuring unit, and the number of measuring units can be one, two, or three, and the number of measuring units is not limited here. There is a corresponding mapping relationship between the bridge arm current value and the bridge arm, and the corresponding bridge arm can be determined according to the collected bridge arm current value. For example, as shown in Figure 3, it is the current value measured by the overcurrent protection in an embodiment, that is, the current flowing into the energy storage valve, as shown in the dotted area 1 marked in Figure 3. For ease of understanding, the overcurrent protection in this example is illustrated by a certain bridge arm of the converter.

In the energy storage valve, when there is an overcurrent, it is necessary to protect the bridge arm flow control valve by locking the bridge arm to improve safety. Overcurrent protection includes temporary overcurrent protection and permanent overcurrent protection. Temporary overcurrent protection can be understood as temporary overcurrent should be able to recover, that is, overcurrent protection caused by temporary interference in the energy storage valve, temporarily locking the valve body, and unlocking the valve body after the overcurrent disappears, which does not affect the operation of the energy storage valve. The valve control system has the ability to self-recover. Permanent overcurrent protection can be understood as the energy storage valve cannot automatically recover after locking the valve body. Temporary overcurrent protection and permanent overcurrent protection can be protected locally in the energy storage valve. For example, overcurrent protection can be performed in the overcurrent detection device of the energy storage valve.

Specifically, the energy valve control system has the ability of self-recovery. After the energy storage valve performs temporary over-current protection, in order to further improve the over-current protection method, the bridge arm current of the bridge arm of the converter in the energy storage valve is detected in real time. If it is detected that the bridge arm current value meets the set current for unlocking the temporary over-current protection, and the duration of the bridge arm current value also reaches the set duration corresponding to the unlocking, the bridge arm is unlocked, that is, the corresponding energy storage valve is unlocked, and the real-time operating parameters of the bridge arm of the converter in the energy storage valve are detected in real time.

Step 204: If the real-time operating parameters of the bridge arm of the converter meet the permanent overcurrent protection bridge arm permanent blocking condition, a permanent overcurrent protection signal is generated and sent to the logic judgment unit for judgment.

Step 206: If the judgment result is that the bridge arm of the converter is permanently overcurrent, the bridge arm of the converter is permanently locked.

Among them, the permanent locking conditions of the bridge arm of permanent overcurrent protection include reaching the set current and set duration of permanent overcurrent protection. The set current and set duration of permanent overcurrent protection are expanded on the basis of temporary overcurrent protection. The set current of permanent overcurrent protection is greater than the set current of temporary overcurrent protection lockout, and the set duration of permanent overcurrent protection is greater than the set duration of temporary overcurrent protection lockout.

When judging whether the real-time operating parameters of the bridge arm of the converter meet the permanent arm permanent locking condition of the bridge arm of the permanent overcurrent protection, the judgment can be made in the following manner: obtaining the real-time operating parameters measured by at least one measuring unit, and judging whether the bridge arm of the converter meets the permanent arm permanent locking condition of the bridge arm of the permanent overcurrent protection according to at least one real-time operating parameter. When judging whether the permanent arm permanent locking condition of the bridge arm of the permanent overcurrent protection is met according to the real-time operating parameters, it can be judged whether the number of temporary locking times in the real-time operating parameters meets the permanent arm permanent locking condition of the bridge arm of the permanent overcurrent protection, or whether the bridge arm current value and duration in the real-time operating parameters meet the permanent arm permanent locking condition of the bridge arm of the permanent overcurrent protection.

It is understandable that when the energy storage valve is protected from overcurrent, in order to improve the reliability, selectivity, sensitivity, speed, controllability, safety, etc. of the overcurrent protection, the execution steps of the overcurrent protection are executed by different processing units respectively.

Specifically, when the real-time operating parameters of the bridge arm of the converter meet the permanent arm permanent locking condition of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment unit in the logic judgment device for judgment, and the judgment result of the logic judgment unit is obtained. If the result is permanent overcurrent protection, the valve control unit of the valve control host performs single bridge arm permanent locking on the bridge arm of the converter. If it is detected that all bridge arms of the converter are in bridge arm permanent locking, the line switch is directly tripped.

In the above embodiment, when overcurrent protection is performed by real-time detection of the operating parameters of the converter, when it is detected in real time that the real-time bridge arm current value and the duration of the converter meet the permanent arm permanent locking condition of the permanent overcurrent protection, the bridge arm of the converter is permanently locked. On the basis of temporary overcurrent protection, permanent overcurrent of the bridge arm is further considered. When the permanent arm permanent locking condition of the permanent overcurrent protection is met, the bridge arm is locked, and the overcurrent of the converter is protected in sections, thereby improving the reliability of the overcurrent protection.

When overcurrent occurs in the converter, corresponding overcurrent protection measures need to be taken according to the type of overcurrent. According to different overcurrent protection measures, the overcurrent protection mode of the energy storage valve is improved to improve the reliability of overcurrent protection.

In one embodiment, a method for temporary overcurrent protection is provided, as shown in FIG4 , comprising the following steps:

Step 402: Acquire a first operating parameter of a bridge arm of the converter.

The first operating parameter at least includes the first bridge arm current value and the duration of the first bridge arm current value. Temporary overcurrent protection can also be understood as single bridge arm temporary overcurrent protection.

Specifically, when the energy storage valve operates normally, temporary overcurrent protection of the energy storage valve is enabled, and a first operating parameter of a bridge arm of the converter in the energy storage valve is detected in real time by at least one measuring unit. Based on the first operating parameter, on-site protection is performed in a local valve protection unit of the energy storage valve.

Step 404: If the first operating parameter satisfies the temporary over-current protection start condition, a temporary over-current protection signal is generated.

Among them, after the temporary overcurrent protection is locked, when the preset unlocking conditions are met, it will automatically recover and unlock the bridge arm. The starting condition of the temporary overcurrent protection can be that when the current value of the first bridge arm is greater than the first set current of the temporary overcurrent protection, the overcurrent duration of the current value of the first bridge arm is greater than the first set duration of the temporary overcurrent protection. The release condition of the temporary overcurrent protection can be that when the current value of the second bridge arm is less than the second set current of the temporary overcurrent protection, the overcurrent duration of the current value of the second bridge arm is greater than the second set duration of the temporary overcurrent protection. The first set current is greater than the second set current, the first set duration is less than the second set duration, the value range of the first set current is 1.2 to 2.0 rated current value, and the rated current value of 1.2 to 2.0 can be understood as (1.2 to 2.0) rated current value, that is, 1.2 to 2.0 times the rated current value; the value range of the second set current is 0 to 1.0 rated current value, and the rated current value of 0 to 1.0 can be understood as (0 to 1.0) rated current value, that is, 0 to 1.0 times the rated current value. Furthermore, the first set time has a value range of 0us to 500us, and the second set time has a value range of 0us to 3000us. The first set current and the first set time are determined according to the temporary overcurrent protection characteristics of the energy storage valve, and the second set current and the second set time are determined according to the self-recovery ability of the energy storage valve.

Step 406: temporarily lock the bridge arm of the converter based on the temporary overcurrent protection signal, and record the number of temporary lockouts of the bridge arm of the converter.

The number of temporary blocking times of the bridge arm of the converter can be understood as follows: when it is determined that the bridge arm of the converter is temporarily blocked, the number of temporary blocking times is increased by 1.

Step 408, obtaining a second operating parameter of the bridge arm of the converter.

The second operating parameter includes the second bridge arm current value and the duration of the second bridge arm current value.

Step 410: If the second operating parameter satisfies the over-current protection release condition, a release over-current protection signal is generated.

Among them, the overcurrent protection release condition may be that the second bridge arm current value is less than the second set current of the overcurrent protection release condition, the duration of the second bridge arm current value is greater than the second set duration of the overcurrent protection release condition, and the second set duration is greater than the first set duration.

Step 412: unlocking the bridge arm of the converter based on the overcurrent protection release signal.

Specifically, if a single bridge arm temporary overcurrent protection action occurs, the bridge arm is locked, it is detected that the overcurrent protection function of stage I is enabled, and the real-time detection of the second bridge arm current is less than the second set current, and the duration is greater than the second set time, the temporary overcurrent protection action returns, the single bridge arm locking flag is cleared, and the temporary overcurrent protection action signal, current value, and bridge arm locking times are sent to the logic judgment unit. The logic judgment unit performs a two-out-of-three judgment, and sends the judgment result to the unlocking signal to unlock the bridge arm.

It can be understood that in order to determine the reliability of the overcurrent protection of the energy storage valve, the energy storage valve can be hardware graded, and the overcurrent protection device can be implemented in a segmented manner. That is, the first operating parameters of the bridge arm of the converter are measured by three measuring units, and the collected first operating parameters are sent to the corresponding local valve protection units respectively, and on-site protection is performed by the valve protection units.

In one embodiment, if at least two valve protection units detect that the corresponding first bridge arm current value is greater than the first set current of the temporary overcurrent protection, and the overcurrent duration of the first bridge arm current value is greater than the first set duration of the temporary overcurrent protection, at least two candidate temporary overcurrent protection signals are generated; the at least two candidate temporary overcurrent protection signals are sent to the logic judgment unit, and the logic judgment unit makes a judgment based on the at least two temporary overcurrent protection signals to generate a temporary overcurrent protection signal. The temporary overcurrent protection signal is sent to the valve control unit, and the bridge arm of the converter is temporarily locked by the valve control unit. Among them, the valve protection unit and the logic judgment unit belong to different functional layers of the energy storage valve control system respectively, and the valve protection unit can also be called an overcurrent detection unit. The logic judgment unit can adopt "three out of two judgment logic" when making a judgment. The number of valve control units can be two, and the two valve control units are redundant with each other.

Specifically, when the energy storage valve control system is operating normally, it is detected that the overcurrent protection function of stage I is enabled, and the first operating parameter of the bridge arm is detected in real time. If the first bridge arm current value of the first operating parameter is greater than the first set current and the duration is greater than the first set duration, the temporary overcurrent protection is activated, the single bridge arm locking flag is set, and the number of bridge arm locking times is accumulated. At the same time, the overcurrent detection chassis sends the temporary overcurrent protection action signal, current value, and bridge arm locking times of the chassis to the logic judgment unit. The logic judgment unit performs a three-out-of-two logic judgment based on the temporary overcurrent action signal of the three logic judgment units and then sends the action signal to the valve control unit to temporarily lock the single bridge arm converter valve. Otherwise, the detection and judgment are continued. Detection is performed by at least two overcurrent detection devices to generate at least two candidate temporary overcurrent protection signals. The logic judgment device judges the at least two candidate temporary overcurrent protection signals to generate a temporary overcurrent protection signal, thereby improving the reliability of temporary overcurrent protection.

As shown in FIG5 , it is a schematic diagram of the steps of a temporary overcurrent protection method in an embodiment, wherein the energy storage valve control system can be a new energy storage valve control system, and the temporary overcurrent protection can be understood as overcurrent I-stage protection. After the new energy storage valve control system is powered on and initialized, it operates normally, the bridge arm locking times N=0, the overcurrent I-stage protection is enabled, and the bridge arm current is detected in real time. If the bridge arm current is greater than the first set current Iset1, and the duration is greater than the first set duration It1, the temporary overcurrent protection is activated, the single bridge arm locking flag is set, and the bridge arm locking times N=N+1 are accumulated. At the same time, the overcurrent detection chassis sends the temporary overcurrent protection action signal, current value, and bridge arm locking times of the chassis to the logic judgment unit. The logic judgment unit performs a three-out-of-two logic judgment based on the temporary overcurrent action signals of the three valve protection units and sends the action signal to the valve control unit for temporary locking of the single bridge arm converter valve. Otherwise, the detection and judgment are continued.

If a single bridge arm temporary overcurrent protection action occurs, the bridge arm is locked, and it is detected that the overcurrent protection function of stage I is enabled. The real-time detection of the bridge arm current is less than the second set current Iset2, and the duration is greater than the second set duration It2. The temporary overcurrent protection action returns, the single bridge arm locking flag is cleared, and the temporary overcurrent protection action signal, current value, and bridge arm locking times are sent to the logic judgment unit for three-out-of-two judgment, and the judgment result is sent to the unlocking signal to unlock the bridge arm.

In the above embodiment, when the bridge arm of the converter is temporarily overcurrented, it is locked, and by further judging whether the overcurrent protection is released, the temporary lock is unlocked considering the recovery ability of the energy storage valve itself, so as to avoid the temporary lock directly tripping the line switch and causing the whole station to stop operating.

In another embodiment, as shown in FIG6 , an overcurrent protection method for an energy storage valve is provided, which is described by taking the application environment in FIG1 as an example, and includes the following steps:

Step 602, when the bridge arm of the converter is released from temporary blocking, obtain the real-time operating parameters of the bridge arm of the converter; the real-time operating parameters include the number of temporary blocking times.

The temporary closing times are the times the bridge arm is temporarily closed. Each time the energy storage valve is temporarily closed, the temporary closing times of the corresponding bridge arm will be updated, and the updating method may be to accumulate the temporary closing times of the bridge arm.

Step 604: If it is detected that the number of temporary blocking times is greater than a set threshold, a permanent over-current protection signal is generated.

The threshold value can be preset according to actual needs, which is the threshold of the number of lockouts. It can be manually set according to project needs. When the number of temporary lockouts N during operation is greater than the set threshold M, it will be permanently locked. The set threshold value can be 50 times, and the set threshold value is not greater than 120 times. The permanent lockout of the bridge arm can be understood as the permanent lockout of a single bridge arm.

Step 606: Send the permanent over-current protection signal to the logic judgment unit for judgment. If the judgment result is that the bridge arm of the converter is permanently over-current, the bridge arm of the converter is permanently locked.

In one embodiment, if at least two valve protection units detect that the number of temporary lockouts is greater than a set threshold, at least two candidate permanent overcurrent protection signals are generated; at least two candidate permanent overcurrent protection signals are sent to the logic judgment unit, and the logic judgment unit makes a judgment based on at least two temporary and permanent protection signals to generate a permanent overcurrent protection signal. The temporary overcurrent protection signal is sent to the valve control unit, and the bridge arm of the converter is permanently locked by the valve control unit. In other words, local permanent overcurrent protection is performed locally at the energy storage valve by at least two valve protection units, and the generated candidate permanent overcurrent protection signal is sent to the logic judgment unit for judgment, and the single-bridge-arm converter valve is permanently locked by the valve control unit, the energy storage valve protection hardware is graded, and segmented protection is performed, the overcurrent protection method is improved, and the reliability of overcurrent protection is improved.

In the above embodiment, in the case of unlocking after temporary blocking, by counting the number of temporary blocking times, when the number of temporary blocking times is greater than a set threshold, the bridge arm of the converter is permanently blocked. By performing segmented overcurrent protection on the bridge arm of the converter, the overcurrent protection method is increased, thereby improving the reliability of the overcurrent protection.

In one embodiment, as shown in FIG. 7 , a permanent overcurrent protection step is provided, which is described by taking the method applied to the application environment in FIG. 1 as an example, including the following:

Step 702, obtaining real-time operating parameters of the bridge arm of the converter.

Specifically, when the bridge arm of the converter is released from temporary blocking, the real-time operating parameters of the bridge arm of the converter are obtained. Alternatively, the real-time operating parameters of the bridge arm of the converter are directly obtained.

Step 704: If it is detected that the number of temporary blocking times in the real-time operating parameters is greater than a set threshold, the bridge arm of the converter is permanently blocked.

Specifically, when the energy storage valve is operating normally, permanent overcurrent protection is enabled. If it is detected that the number of temporary lockouts is greater than the set threshold, a permanent overcurrent protection signal is generated, and a single bridge arm permanent lockout flag is set for the bridge arm corresponding to the real-time bridge arm current value, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment. If it is judged that the bridge arm corresponding to the real-time bridge arm current value is permanently overcurrent, the permanent overcurrent protection signal is sent to the valve control unit for control, and the bridge arm of the converter is permanently locked based on the permanent overcurrent protection signal.

Step 706: If it is detected that the real-time bridge arm current value and the duration in the real-time operation parameters meet the bridge arm permanent blocking condition of the permanent overcurrent protection, the bridge arm of the converter is permanently blocked.

Among them, the permanent arm locking condition of the permanent overcurrent protection can be that the real-time arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection, the third set current value range is 1.5 to 2.0 rated current value, and the third set duration value range is 0us to 1000us. 1.5 to 2.0 rated current value can be understood as (1.5 to 2.0) rated current value, that is, 1.5 to 2.0 times the rated current value. Specifically, when the energy storage valve is operating normally, permanent overcurrent protection is enabled. If it is detected that the real-time bridge arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the bridge arm corresponding to the real-time bridge arm current value is set with a single bridge arm permanent locking flag, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment. If it is judged that the bridge arm corresponding to the real-time bridge arm current value is permanently overcurrent, the permanent overcurrent protection signal is sent to the valve control unit for control, and the bridge arm of the converter is permanently locked based on the permanent overcurrent protection signal.

Furthermore, in view of the fact that the existing energy storage valve overcurrent protection mode is single and the reliability of the overcurrent protection is not high, the overcurrent protection is implemented by layering the hardware of the energy storage valve, the overcurrent protection is improved, and the reliability of the overcurrent protection is improved.

In one embodiment, if at least two valve protection units detect that the corresponding real-time bridge arm current value is greater than the third set current of permanent overcurrent protection and the duration is greater than the third set duration of permanent overcurrent protection, at least two candidate permanent overcurrent protection signals are generated; at least two candidate permanent overcurrent protection signals are sent to the logic judgment unit, and the logic judgment unit makes a judgment based on at least two candidate permanent overcurrent protection signals to generate a permanent overcurrent protection signal. The permanent overcurrent protection signal is sent to the valve control unit to permanently lock the bridge arm of the converter. When performing permanent overcurrent protection, the valve protection unit performs on-site protection in a hardware graded and overcurrent protection segmented manner. After generating the candidate permanent overcurrent protection signal, the logic judgment unit performs a logic judgment to determine the final permanent overcurrent protection signal to send to the valve control unit to permanently lock the bridge arm. The energy storage valve can be protected from overcurrent at multiple levels and in multiple directions, thereby improving the reliability of the energy storage valve.

In the above embodiment, whether permanent overcurrent protection is triggered is judged by obtaining the number of temporary locking times of the bridge arm of the converter, or detecting the bridge arm current value and the duration of the bridge arm current value in real time. The reliability of the overcurrent protection of the energy storage valve is improved by stratifying the system hardware and segmenting the overcurrent protection.

In another embodiment, an overcurrent protection method for an energy storage valve is provided, which is described by taking the application environment in FIG. 1 as an example, as shown in FIG. 8 , including the following steps:

Step 802, obtaining real-time operating parameters of the bridge arm of the converter; the real-time operating parameters at least include the real-time bridge arm current value and the duration of the real-time bridge arm current value.

Step 804: When the real-time operating parameters of the bridge arm of the converter meet the permanent arm permanent blocking condition of the permanent overcurrent protection, a permanent overcurrent protection signal is generated and sent to the logic judgment unit for judgment.

Among them, the temporary over-current protection and permanent over-current protection of the energy storage valve can be achieved by the above-mentioned method, which will not be described in detail here.

Step 806: If the judgment result is that the bridge arm of the converter is permanently overcurrent, the bridge arm of the converter is permanently locked.

Step 808: If it is detected that all bridge arms of the converter are not in the state of permanent bridge arm blocking, obtain the third operating parameter of the bridge arm of the converter in the state of permanent bridge arm blocking.

The third operating parameter includes a third bridge arm current value of the bridge arm of the converter and a duration of the third bridge arm current value. The third operating parameter can be obtained by a measuring unit.

It can be understood that the permanent overcurrent protection of the whole bridge arm is after the permanent overcurrent protection of the single bridge arm is executed. If it is detected that all the bridge arms of the converter are not in the permanent lockout of the bridge arm, in order to avoid three-phase imbalance and serious impact on the other two bridge arms, the circuit breaker should be tripped in time to prevent the expansion of the fault.

Step 810: If the third operating parameter satisfies the permanent overcurrent protection condition of the entire bridge arm, the entire converter is locked and the line switch is tripped.

Among them, the permanent overcurrent protection condition for the whole bridge arm can be that after the permanent overcurrent protection of a single bridge arm, the bridge arm current value detected in real time is greater than the fourth set current of the permanent overcurrent protection of the whole bridge arm and the duration is greater than the fourth set duration of the permanent overcurrent protection of the whole bridge arm. The fourth set current value range is 2.0 to 3.0 rated current values, and the fourth set duration value range is 0us to 1000us. The fourth set current value and the fourth set duration are determined based on the electrical and insulation tolerance time of other bridge arms in the energy storage system, which can avoid the impact on the system caused by the expansion of the scope of the accident. The rated current value of 2.0 to 3.0 can be understood as (2.0 to 3.0) rated current values, that is, 2.0 to 3.0 times the rated current value.

It is understandable that the energy storage valve has more than one bridge arm. After detecting the permanent overcurrent protection of a single bridge arm, if it is detected that the third operating parameter of any bridge arm meets the permanent overcurrent protection condition of the entire bridge arm, the entire converter is locked and the line switch is jumped.

Specifically, when the energy storage valve is operating normally, the protection function of the permanent overcurrent protection of the whole bridge arm is enabled, and it is detected whether there is a permanent overcurrent action of the bridge arm. If not, it is continuously detected. If yes, it is determined whether all the bridge arms are locked. If they are all locked, the overcurrent protection ends. If the converter valves of the whole bridge arm are not all locked, the third bridge arm current value of the locked bridge arm is detected in real time. If the third bridge arm current value is greater than the fourth set current and the duration is greater than the fourth set time, the three-phase full bridge arm converter is locked at this time, the permanent lock flag of the full bridge arm converter is set, and the line switch is jumped to wait for shutdown and maintenance.

In the above embodiment, by segmenting the overcurrent protection of the energy storage valve, temporary overcurrent protection is used to implement overcurrent protection caused by temporary interference of the bridge arm, and the valve body is temporarily locked. After the overcurrent disappears, the valve body is unlocked, which does not affect the operation of the energy storage valve, and the valve control system has the ability of self-recovery; on the basis of temporary overcurrent protection, the time limit and the set value are extended, and after the requirements of the set value and the time limit are met, the single bridge arm permanent valve is locked to protect the bridge arm flow control valve; on the basis of permanent overcurrent protection, after the permanent locking of the single bridge arm is detected, the whole bridge arm is locked and the incoming line switch is opened according to the electrical and insulation tolerance time of other bridge arms, thereby avoiding the impact on the system caused by the expansion of the accident scope, improving the overcurrent protection method, and improving the reliability of the energy storage valve.

On the basis of segmenting the overcurrent protection mode of the energy storage valve, by grading the system hardware and realizing permanent overcurrent protection of the whole bridge arm on the logic judgment unit or the valve control unit side, the overcurrent protection mode is further improved, and the reliability of the energy storage system is improved.

In one embodiment, if the logic judgment unit or the valve control unit detects that the current value of the third bridge arm is greater than the fourth set current of the permanent overcurrent protection of the full bridge arm and the duration of the current value of the third bridge arm is greater than the fourth set duration of the permanent overcurrent protection of the full bridge arm, the entire converter is locked and the line switch is jumped.

Specifically, when the energy storage valve operates normally, after the permanent overcurrent protection is triggered, the protection function of the permanent overcurrent protection of the whole bridge arm is enabled, and the permanent overcurrent protection of the whole bridge arm is performed through the logic judgment unit or the valve control unit. If the logic judgment unit or the valve control unit detects that the current value of the third bridge arm is greater than the fourth set current of the permanent overcurrent protection of the whole bridge arm and the duration of the current value of the third bridge arm is greater than the fourth set duration of the permanent overcurrent protection of the whole bridge arm, the three-phase full-bridge arm converter is locked, the permanent locking flag of the full-bridge arm converter is set, and the line switch is jumped to wait for shutdown and maintenance.

In one embodiment, a data interaction diagram of an overcurrent protection method for an energy storage valve is shown in FIG9 , including a valve control unit A and a valve control unit B, a logic judgment unit A and a logic judgment unit B, a valve protection unit A, a valve protection unit B and a valve protection unit C, and a measurement unit A, a measurement unit B and a measurement unit C. The valve control unit A and the valve control unit B are mutually redundant, and the logic judgment unit A and the logic judgment unit B are mutually redundant. The overcurrent protection of the energy storage valve in stage I and stage II is realized by the valve protection unit, and the overcurrent protection in stage III is realized by the logic judgment unit or the valve control unit. The energy storage valve control system operates normally after power-on initialization. The bridge arm current of the converter in the energy storage valve control system is measured by three measuring units. The three valve protection units detect the first operating parameter of the bridge arm in real time. If the first bridge arm current value of the first operating parameter is greater than the first set current and the duration is greater than the first set duration, the temporary overcurrent protection is activated, the single bridge arm locking flag is set, and the number of bridge arm locking times is accumulated. At the same time, the overcurrent detection chassis sends the temporary overcurrent protection action signal, current value, and bridge arm locking times of the chassis to the logic judgment unit. The logic judgment unit performs a three-out-of-two logic judgment based on the temporary overcurrent action signals of the three logic judgment units based on the three-out-of-two judgment logic, and then sends the action signal to the valve control unit. The single bridge arm converter valve is temporarily locked through the valve control unit. Otherwise, the detection and judgment are continued.

If a single bridge arm temporary overcurrent protection action occurs and the bridge arm is locked, the three valve protection units detect that the overcurrent I protection function is enabled, and the three valve protection units detect that the second detection bridge arm current is less than the second set current Iset2, and the duration is greater than the second set duration It2, the temporary overcurrent protection action returns, the single bridge arm locking flag is cleared, and the temporary overcurrent protection action signal, current value, and bridge arm locking times are sent to the logic judgment unit for three-out-of-two judgment, and the judgment result is sent to the unlocking signal, and the bridge arm is unlocked through the valve control unit. On the basis of overcurrent section I, under the normal operation of the energy storage valve control system, the protection of overcurrent section II is enabled. If the three valve protection units detect that the number of temporary lockouts is greater than the set threshold, or the real-time bridge arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection, three single-bridge arm permanent overcurrent protection actions are generated, and the single-bridge arm lockout flag is set. At the same time, the valve protection unit sends the permanent overcurrent protection action signal, current value, and bridge arm lockout times to the logic judgment unit, and after a two-out-of-three logic judgment is performed based on the permanent overcurrent action signals of the three valve protection units, the action signal is sent to the valve control unit for permanent locking of the single-bridge arm converter valve. Otherwise, continuous detection and judgment are performed.

When the energy storage valve control system operates normally, after the permanent overcurrent protection is triggered, the protection function of the permanent overcurrent protection of the whole bridge arm is enabled, and the permanent overcurrent protection of the whole bridge arm is performed through the logic judgment unit or the valve control unit. If the logic judgment unit or the valve control unit detects that the current value of the third bridge arm is greater than the fourth set current of the permanent overcurrent protection of the whole bridge arm and the duration of the current value of the third bridge arm is greater than the fourth set duration of the permanent overcurrent protection of the whole bridge arm, the three-phase full bridge arm converter is locked, the permanent locking flag of the full bridge arm converter is set, and the line switch is jumped to wait for shutdown and maintenance.

It can be understood that overcurrent section I is a low set value and a low time limit. After the temporary overcurrent protection is activated, the overcurrent section I protection can be exited when the current returns to the normal value; when the lockout exceeds the limit value in overcurrent section I, or exceeds the high set value and time limit of overcurrent protection II, it is permanently locked; overcurrent section III is to lock other bridge arms after overcurrent section II is activated and exceeds the high current set value and time limit to avoid expanding the scope of the accident. That is, by dividing the bridge arm overcurrent protection into section III, overcurrent section I and overcurrent section II are protected by the valve protection unit, overcurrent section III is protected by the logic judgment unit or the valve control unit, the energy storage valve protection hardware is graded, the software is segmented for protection, and the overcurrent protection is carried out in all directions and at multiple levels, which realizes the selective fault isolation at the time point after the fault occurs, improves the overcurrent protection strategy, and enhances the reliability of the energy storage valve.

Based on the same inventive concept, the embodiment of the present application also provides an energy storage valve for implementing the above-mentioned energy storage valve overcurrent protection method. The implementation scheme for solving the problem provided by the system is similar to the implementation scheme recorded in the above-mentioned method, so the specific limitations in the overcurrent protection system embodiment of one or more energy storage valves provided below can refer to the above-mentioned limitations on the overcurrent protection method of the energy storage valve, and will not be repeated here.

In one embodiment, as shown in FIG. 10 , an overcurrent protection system for an energy storage valve is provided, the system comprising an overcurrent detection module 1002 , a logic judgment module 1004 and a valve control module 1006 , wherein:

The overcurrent detection module 1002 is used to perform overcurrent detection on the real-time operating parameters of the bridge arm of the converter; if it is detected that the real-time operating parameters meet the permanent locking condition of the bridge arm of the permanent overcurrent protection of the valve control module, a permanent overcurrent protection signal is generated and sent to the logic judgment module.

The logic judgment module 1004 is used to judge the received permanent over-current protection signal and obtain a judgment result; if the judgment result is that the bridge arm is permanently over-current, the permanent over-current protection signal is sent to the valve control module 1006.

The valve control module 1006 is used to respond to the permanent overcurrent protection signal and permanently lock the bridge arm of the converter.

In the above embodiment, overcurrent protection is performed by real-time detection of the operating parameters of the converter. When it is detected in real time that the real-time bridge arm current value and the duration of the converter meet the permanent arm permanent locking condition of the permanent overcurrent protection, the permanent overcurrent protection signal is sent to the logic judgment unit to achieve permanent arm locking of the converter. When the permanent arm locking condition of the permanent overcurrent protection is met, the converter is locked, and the corresponding bridge arm of the converter is protected from overcurrent, instead of directly locking the entire converter and jumping the line switch. The overcurrent protection of the converter is segmented, thereby improving the reliability of the overcurrent protection.

Optionally, in one embodiment, the overcurrent detection module 1002 is also used to perform overcurrent detection on the first operating parameter of the bridge arm of the converter. If the first operating parameter meets the temporary overcurrent protection start-up condition, a temporary overcurrent protection signal is generated, the number of temporary locking times of the bridge arm of the converter is recorded, and the temporary overcurrent protection signal is sent to the logic judgment module.

Optionally, in one embodiment, the logic judgment module 1004 is also used to judge the received temporary over-current protection signal to obtain a judgment result; if the judgment result is temporary over-current, the temporary over-current protection signal is sent to the valve control module.

Optionally, in one embodiment, the valve control module 1006 is further configured to respond to a temporary overcurrent protection signal to temporarily lock the bridge arm of the converter.

Optionally, in one embodiment, the overcurrent detection module 1002 is also used to perform overcurrent detection on the second operating parameter of the bridge arm of the converter. If the second operating parameter meets the overcurrent protection release condition, an overcurrent protection release signal is generated and sent to the logic judgment module 1004.

Optionally, in one embodiment, the logic judgment module 1004 is also used to judge the received overcurrent protection release signal to obtain a judgment result; if the judgment result is that the overcurrent is released, the overcurrent protection release signal is sent to the valve control module.

Optionally, in one embodiment, the valve control module 1006 is further configured to respond to a release overcurrent protection signal and unlock a bridge arm of the converter.

Optionally, in one embodiment, the logic judgment module 1004 is also used to perform overcurrent detection on the third operating parameter of the bridge arm of the converter that is in permanent bridge arm locking when it is detected that all bridge arms of the converter are not in permanent bridge arm locking; if the third operating parameter meets the permanent overcurrent protection condition of the entire bridge arm, a permanent overcurrent protection signal for the entire bridge arm is generated; and the permanent overcurrent protection signal for the entire bridge arm is sent to the valve control module 1006.

Optionally, in one embodiment, the valve control module 1006 is further configured to respond to a permanent overcurrent protection signal of the entire bridge arm, lock the entire converter and trip the line switch.

Optionally, in one embodiment, the valve control module 1006 is also used to perform overcurrent detection on the third operating parameter of the bridge arm of the converter that is in permanent bridge arm locking when it is detected that all bridge arms of the converter are not in permanent bridge arm locking. If the third operating parameter meets the permanent overcurrent protection condition of the entire bridge arm, the entire converter is locked and the line switch is tripped.

Optionally, in one embodiment, the overcurrent detection module 1002 is also used to generate at least two candidate temporary overcurrent protection signals if at least two valve protection modules detect that the corresponding first bridge arm current value is greater than the first set current of the temporary overcurrent protection, and the overcurrent duration of the first bridge arm current value is greater than the first set duration of the temporary overcurrent protection; and send the at least two candidate temporary overcurrent protection signals to the logic judgment module.

Optionally, the logic judgment module 1004 is further configured to make a judgment based on at least two temporary over-current protection signals to generate a temporary over-current protection signal.

Optionally, the valve control module 1006 is further configured to temporarily lock a bridge arm of the converter.

Optionally, in one embodiment, the overcurrent detection module 1002 is further configured to generate a permanent overcurrent protection signal if it is detected that the number of temporary blocking times is greater than a set threshold.

Optionally, in one embodiment, the overcurrent detection module 1002 is also used to generate a permanent overcurrent protection signal when the number of temporary lockout times is less than a set threshold and if the real-time bridge arm current value and duration meet the permanent lockout condition of the bridge arm for permanent overcurrent protection.

Optionally, in one embodiment, the overcurrent detection module 1002 is also used to generate a permanent overcurrent protection signal if the real-time bridge arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection, and send the permanent overcurrent protection signal to the logic judgment module for judgment.

Optionally, in one embodiment, the logic judgment module 1004 is also used to make a judgment based on at least two candidate permanent overcurrent protection signals generated by the overcurrent detection module 1002 if at least two candidate permanent overcurrent protection signals are received; if at least one candidate permanent overcurrent protection signal indicates that the bridge arm of the converter is permanently overcurrent, it is determined that the bridge arm of the converter is permanently overcurrent.

Optionally, in one embodiment, the valve control module 1006 is further configured to permanently lock the bridge arm of the converter based on the permanent overcurrent protection signal.

Optionally, in one embodiment, the valve control module 1006 is further used to lock the entire converter and jump the line switch if the third operating parameter meets the permanent overcurrent protection condition of the whole bridge arm. Each module of the overcurrent protection system of the above energy storage valve can be implemented in whole or in part by software, hardware and a combination thereof. The above modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be shown in FIG11. The computer device includes a processor, a memory, a communication interface, a display screen, and an input device connected via a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner may be implemented through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, an overcurrent protection method for an energy storage valve is implemented. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covered on the display screen, or a key, a trackball or a touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

Those skilled in the art will understand that the structure shown in FIG11 is merely a block diagram of a partial structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

In one embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiments when executing the computer program.

In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchain, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, etc., but are not limited to this.

The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be noted that, for a person of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present patent application shall be subject to the attached claims.

Claims

An overcurrent protection method for an energy storage valve, characterized in that the method comprises:

Acquire real-time operating parameters of the bridge arm of the converter; the real-time operating parameters at least include a real-time bridge arm current value and a duration of the real-time bridge arm current value;

If the real-time operating parameters of the bridge arm of the converter meet the permanent arm permanent locking condition of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment;

If the judgment result is that the bridge arm of the converter is permanently overcurrent, the bridge arm of the converter is permanently locked.
The method according to claim 1, characterized in that before obtaining the real-time operating parameters of the bridge arm of the converter, the method further comprises:

Acquire a first operating parameter of a bridge arm of the converter;

If the first operating parameter meets the temporary over-current protection start condition, a temporary over-current protection signal is generated;

Temporarily blocking the bridge arm of the converter based on the temporary overcurrent protection signal, and recording the number of temporary blocking times of the bridge arm of the converter;

Acquire a second operating parameter of the bridge arm of the converter;

If the second operating parameter satisfies the overcurrent protection release condition, generating an overcurrent protection release signal;

The bridge arm of the converter is unlocked based on the overcurrent protection release signal.
The method according to claim 2, characterized in that the first operating parameter includes a first bridge arm current value and a duration of the first bridge arm current value, and if the first operating parameter satisfies a temporary overcurrent protection start condition, generating a temporary overcurrent protection signal comprises:

If at least two valve protection units detect that the corresponding first bridge arm current value is greater than the first set current of temporary overcurrent protection, and the overcurrent duration of the first bridge arm current value is greater than the first set duration of the temporary overcurrent protection, at least two candidate temporary overcurrent protection signals are generated;

At least two of the candidate temporary over-current protection signals are sent to a logic judgment unit, and the logic judgment unit makes a judgment based on the at least two temporary over-current protection signals to generate a temporary over-current protection signal.
The method according to claim 3, characterized in that the temporarily locking the bridge arm of the converter based on the temporary overcurrent protection signal comprises:

The temporary over-current protection signal is sent to the valve control unit, and the bridge arm of the converter is temporarily locked by the valve control unit.
The method according to claim 2 is characterized in that the first set current has a value range of 1.2 to 2.0 rated current values, and the first set duration has a value range of 0 to 500 us.
The method according to claim 2 is characterized in that the temporary overcurrent protection release condition includes a second set current and a second set time, the first set current is greater than the second set current, the first set time is less than the second set time, the second set current value range is 0 to 1.0 rated current value, and the second set time value range is 0 to 3000us.
The method according to claim 1, characterized in that the real-time operating parameters further include the number of temporary blocking times, and if the real-time operating parameters of the bridge arm of the converter meet the permanent blocking condition of the bridge arm of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, comprising:

If it is detected that the temporary blocking times are greater than a set threshold, a permanent over-current protection signal is generated.
The method according to claim 1, characterized in that the real-time operating parameters further include the number of temporary blocking times, and if the real-time operating parameters of the bridge arm of the converter meet the permanent blocking condition of the bridge arm of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, comprising:

When the number of temporary lockouts is less than a set threshold, if the real-time bridge arm current value and the duration meet the bridge arm permanent lockout condition of permanent overcurrent protection, a permanent overcurrent protection signal is generated.
The method according to claim 1 is characterized in that if the real-time operating parameters of the bridge arm of the converter meet the permanent arm permanent locking condition of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment, comprising:

If the real-time bridge arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection, a permanent overcurrent protection signal is generated and sent to the logic judgment unit for judgment.
The method according to claim 9 is characterized in that if the real-time bridge arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to a logic judgment unit for judgment, comprising:

If at least two valve protection units detect that the corresponding real-time bridge arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection, at least two candidate permanent overcurrent protection signals are generated;

Sending at least two of the candidate permanent over-current protection signals to a logic judgment unit, and the logic judgment unit makes a judgment based on the at least two candidate permanent over-current protection signals;

If at least one of the candidate permanent overcurrent protection signals indicates that the bridge arm of the converter is permanently overcurrent, it is determined that the bridge arm of the converter is permanently overcurrent.
The method according to claim 10, characterized in that if the bridge arm of the converter is permanently overcurrent, the bridge arm of the converter is permanently locked, comprising:

The permanent overcurrent protection signal is sent to the valve control unit, and the bridge arm of the converter is permanently locked by the valve control unit.
The method according to claim 9 is characterized in that the third set current value ranges from 1.5 to 2.0 rated current values, and the third set time length ranges from 0 to 1000 us.
The method according to any one of claims 1, 8 or 9, characterized in that the method further comprises:

If it is detected that all bridge arms of the converter are not in the state of permanent arm locking, obtaining a third operating parameter of the bridge arm of the converter in the state of permanent arm locking; the third operating parameter includes a third bridge arm current value of the bridge arm of the converter and a duration of the third bridge arm current value;

If the third operating parameter satisfies the permanent overcurrent protection condition of the entire bridge arm, the entire converter is locked and the line switch is tripped.
The method according to claim 13, characterized in that if the third operating parameter satisfies the permanent overcurrent protection condition of the entire bridge arm, the entire converter is locked and the line switch is tripped, comprising:

If the logic judgment unit or the valve control unit detects that the current value of the third bridge arm is greater than the fourth set current of the permanent overcurrent protection of the full bridge arm and the duration of the third bridge arm current value is greater than the fourth set duration of the permanent overcurrent protection of the full bridge arm, the entire converter is locked and the line switch is jumped.
The method according to claim 14 is characterized in that the fourth set current value range is 2.0 to 3.0 rated current values, and the fourth set time value range is 0 to 1000 us.
An overcurrent protection system for an energy storage valve, characterized in that the system comprises a valve control module, an overcurrent detection module and a logic judgment module, wherein:

The overcurrent detection module is used to perform overcurrent detection on the real-time operating parameters of the bridge arm of the converter; if it is detected that the real-time operating parameters meet the permanent locking condition of the bridge arm of the permanent overcurrent protection of the valve control module, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment module;

The logic judgment module is used to judge the received permanent over-current protection signal to obtain a judgment result; if the judgment result is that the bridge arm is permanently over-current, the permanent over-current protection signal is sent to the valve control module;

The valve control module is used to respond to the permanent overcurrent protection signal and permanently lock the bridge arm of the converter.
The system according to claim 16 is characterized in that the overcurrent detection module is used to perform overcurrent detection on the first operating parameter of the bridge arm of the converter, and if the first operating parameter meets the temporary overcurrent protection start condition, a temporary overcurrent protection signal is generated, the number of temporary blocking times of the bridge arm of the converter is recorded, and the temporary overcurrent protection signal is sent to the logic judgment module;

The logic judgment module is used to judge the received temporary over-current protection signal to obtain a judgment result; if the judgment result is temporary over-current, the temporary over-current protection signal is sent to the valve control module;

The valve control module is used to respond to the temporary over-current protection signal and temporarily lock the bridge arm of the converter;

The overcurrent detection module is further used to perform overcurrent detection on the acquired second operating parameter of the bridge arm of the converter, and if the second operating parameter meets the overcurrent protection release condition, generate an overcurrent protection release signal, and send the overcurrent protection release signal to the logic judgment module;

The logic judgment module is used to judge the received overcurrent protection release signal to obtain a judgment result; if the judgment result is that the overcurrent is released, the overcurrent protection release signal is sent to the valve control module;

The valve control module is used to respond to the overcurrent protection release signal to unlock the bridge arm of the converter.
The system according to claim 16, characterized in that the logic judgment module is further used to perform overcurrent detection on the third operating parameter of the bridge arm of the converter that is in the permanent arm lock when it is detected that all bridge arms of the converter are not in the permanent arm lock;

If the third operating parameter satisfies the full-bridge arm permanent overcurrent protection condition, a full-bridge arm permanent overcurrent protection signal is generated; and the full-bridge arm permanent overcurrent protection signal is sent to the valve control module;

The valve control module is used to respond to the permanent over-current protection signal of the full-bridge arm, lock the entire converter and jump the line switch.
The system according to claim 16 is characterized in that the valve control module is also used to perform overcurrent detection on the third operating parameter of the bridge arm of the converter that is in permanent bridge arm locking when it is detected that all bridge arms of the converter are not in permanent bridge arm locking, and if the third operating parameter meets the permanent overcurrent protection condition of the entire bridge arm, the entire converter is locked and the line switch is tripped.
A computer device comprises a memory and a processor, wherein the memory stores a computer program, and wherein the processor implements the steps of any one of the methods of claims 1 to 16 when executing the computer program.
A computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the steps of the method described in any one of claims 1 to 16 are implemented.
A computer program product, comprising a computer program, characterized in that when the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 16 are implemented.