CN117110797A - Multi-criterion-based single-phase earth fault positioning method and device for power distribution network - Google Patents
Multi-criterion-based single-phase earth fault positioning method and device for power distribution network Download PDFInfo
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Abstract
The invention relates to a method and a device for locating single-phase earth faults of a power distribution network based on multiple criteria, wherein the method comprises the following steps: acquiring zero sequence voltages and zero sequence currents of a plurality of buses and a plurality of branches corresponding to each bus before and after a fault in real time; determining a first criterion based on the zero sequence current, the zero sequence voltage and the fundamental wave phase corresponding to the zero sequence current and the zero sequence voltage of each branch; extracting transient characteristics of the zero sequence voltage and the zero sequence current based on a prony filtering algorithm, and determining a second criterion; determining a third data based on the zero sequence current mutation quantity waveform and a wavelet packet filtering algorithm of each branch in the line; based on analytic hierarchy process or Bayesian probability, comprehensively judging the fault line of each bus through the first criterion, the second criterion and the third criterion. The invention improves the line selection success rate of the low-current grounding system and adapts to various scenes by adopting a multi-criterion fault positioning algorithm combining steady-state analysis and transient analysis.
Description
Technical Field
The invention belongs to the technical field of power detection, and particularly relates to a method and a device for positioning single-phase earth faults of a power distribution network based on multiple criteria.
Background
Most of the power distribution network adopts a small current grounding mode, and is characterized in that: when single-phase earth fault occurs, short circuit is not formed, fault current is smaller, the protection device does not act, and the fault can automatically disappear and restore insulation under most conditions. However, when a permanent earth fault occurs, a sustained increase in the voltage of the non-faulty phase leads to an increase in the fault, and therefore the faulty line must be accurately and timely determined. For a long time, the problem is not solved well, and the line selection accuracy of the on-site line selection device is generally low.
When the single-phase grounding is carried out, the transient process comprises a characteristic quantity which is much larger than that of the steady-state process, and the accuracy of line selection can be greatly improved by utilizing the transient algorithm for line selection. The traditional signal processing method such as a fourier algorithm, an FFT and the like can only process steady-state signals basically, but cannot process transient signals. The wavelet analysis method is a time-domain localization analysis method with changeable time window and frequency window. The method has higher frequency resolution and lower time resolution in the low frequency part; the high frequency part has higher time resolution and lower frequency resolution.
With the popularization and progress of edge computation of smart grids, it has become a trend to obtain intrinsic feature information of the waveforms of the grids in multiple dimensions.
Disclosure of Invention
In order to improve the line selection success rate of the arc suppression coil grounding system and the adaptability of the single-phase grounding fault of the power distribution network, the first aspect of the invention provides a multi-criterion-based single-phase grounding fault positioning method of the power distribution network, which comprises the following steps: acquiring zero sequence voltages and zero sequence currents of a plurality of buses and a plurality of branches corresponding to each bus before and after a fault in real time; determining a first criterion based on the zero sequence current, the zero sequence voltage and the fundamental wave phase corresponding to the zero sequence current and the zero sequence voltage of each branch; extracting transient characteristics of the zero sequence voltage and the zero sequence current based on a prony filtering algorithm, and determining a second criterion; determining a third criterion based on zero sequence current mutation quantity waveforms and wavelet packet filtering algorithm of each branch in the bus; based on analytic hierarchy process or Bayesian probability, comprehensively judging the fault line of each bus through the first criterion, the second criterion and the third criterion.
In some embodiments of the invention, the first criterion comprises:
determining three branches with the largest current amplitude change, and judging whether each branch has faults or not according to zero flows and zero pressures of the three branches and respective fundamental wave phases; and constructing differential current and braking current according to zero sequence currents of all branches of the same-section bus, and judging whether each branch has faults or not by adopting a ratio braking principle.
Further, the constructing differential current and braking current according to the zero sequence current of all the branches of the same bus, and judging whether each branch has faults by adopting a ratio braking principle comprises: determining differential current and braking current of the same-section bus, and determining an action equation according to the differential current and the braking current; and judging whether each branch has faults or not based on the action equation.
In some embodiments of the invention, the second criterion comprises: calculating the Lyapunov exponent of the zero sequence current or zero sequence voltage after each branch is filtered by a LongGregory tower method; judging whether each branch has faults or not based on the Lyapunov exponent: if the Lyapunov exponent of a certain branch is larger than a preset value, judging that the branch has faults.
Further, the calculating the lyapunov exponent of the zero sequence current or zero sequence voltage after filtering by the longgrid tower method includes: acquiring circuit parameters of a plurality of branches corresponding to each bus, and determining a dynamic equation of a circuit model according to the circuit parameters of the plurality of branches and the filtered zero sequence current data; calculating the track of the dynamic equation by a Dragon-Gregory tower method; the Lyapunov exponent is calculated from the Wolf method and the trajectory of the dynamic equation.
In some embodiments of the invention, the third criterion comprises: determining a decomposition order and an energy entropy of a wavelet packet transform based on the Hilbert transform; according to the decomposition order and the energy entropy, decomposing the zero sequence current mutation quantity waveform through a wavelet packet filtering algorithm to obtain a fundamental wave and a plurality of harmonic waves; judging whether each branch has faults or not according to the amplitude, the phase and the energy entropy of the fundamental wave and the harmonic wave.
In a second aspect of the present invention, there is provided a single-phase earth fault locating device for a power distribution network based on multiple criteria, including: the acquisition module is used for acquiring the zero sequence voltage and the zero sequence current of the buses and the corresponding branches before and after the fault in real time; the first criterion module is used for determining a first criterion based on the zero sequence current and the zero sequence voltage of each branch and the fundamental wave phase corresponding to the zero sequence current and the zero sequence voltage; the second criterion module is used for extracting transient characteristics of the zero sequence voltage and the zero sequence current based on a prony filtering algorithm and determining a second criterion; the third criterion module is used for determining a third criterion based on the zero sequence current mutation quantity waveform and the wavelet packet filtering algorithm of each branch in the bus; the judging module is used for comprehensively judging the fault line of each bus through the first criterion, the second criterion and the third criterion based on the analytic hierarchy process or the Bayesian probability.
In a third aspect of the present invention, there is provided an electronic apparatus comprising: one or more processors; and the storage device is used for storing one or more programs, and when the one or more programs are executed by the one or more processors, the one or more processors are enabled to realize the multi-criterion-based single-phase grounding fault positioning method for the power distribution network provided by the first aspect.
In a fourth aspect of the present invention, a computer readable medium is provided, on which a computer program is stored, wherein the computer program, when executed by a processor, implements the multi-criterion based single-phase earth fault localization method for a power distribution network provided in the first aspect of the present invention.
The beneficial effects of the invention are as follows:
according to the invention, by adopting a plurality of line selection algorithms combining steady-state analysis and transient analysis, the distribution condition of steady-state and transient signals of each branch zero sequence loop in the ground fault process is calculated, so that the ground line is accurately judged. By the line selection method based on the ground fault parameter identification sensor, the zero sequence loop parameter of the power distribution network fault line is distinguished from the non-fault line, the line selection success rate of the low-current grounding system can be greatly improved, constant value self-adaption is realized, and each scene can be self-adapted without configuring a constant value.
Drawings
FIG. 1 is a basic flow diagram of a multi-criterion based single-phase earth fault localization method for a power distribution network in accordance with some embodiments of the present invention;
FIG. 2 is a schematic diagram of a multi-criterion based single-phase earth fault localization method for a power distribution network in accordance with some embodiments of the present invention;
FIG. 3 is a waveform schematic of zero sequence current before filtering in some embodiments of the invention;
FIG. 4 is a schematic waveform diagram of a filtered zero sequence current in some embodiments of the invention;
FIG. 5 is a schematic diagram of a single-phase earth fault locating device for a power distribution network based on multiple criteria in some embodiments of the invention;
fig. 6 is a schematic structural diagram of an electronic device in some embodiments of the invention.
Detailed Description
The principles and features of the present invention are described below with reference to the drawings, the examples are illustrated for the purpose of illustrating the invention and are not to be construed as limiting the scope of the invention.
Referring to fig. 1 and 2, in a first aspect of the present invention, there is provided a method for locating a single-phase earth fault of a power distribution network based on multiple criteria, including: s100, acquiring zero sequence voltages and zero sequence currents of a plurality of buses and a plurality of branches corresponding to each bus before and after a fault in real time; s200, determining a first criterion based on the zero sequence current, the zero sequence voltage and the fundamental wave phase corresponding to the zero sequence current and the zero sequence voltage of each branch; s300, extracting transient characteristics of zero sequence voltage and zero sequence current based on a prony filtering algorithm, and determining a second criterion; s400, determining a third criterion based on zero sequence current mutation quantity waveforms and wavelet packet filtering algorithm of each branch in the bus; s500, comprehensively judging the fault line of each bus through the first criterion, the second criterion and the third criterion based on an analytic hierarchy process or Bayesian probability.
It can be understood that in the embodiment of the invention, because the real-time wave recording is based on high sampling rate and full synchronization, the system calculates whether the zero sequence voltage of each bus and the zero sequence current of each line of the system are over-limited in real time, if any zero sequence voltage and zero sequence current are over-limited, the system is considered to possibly generate single-phase grounding faults, and after voltage abnormality caused by faults such as non-PT disconnection, ferromagnetic resonance and the like is eliminated and single-phase grounding is confirmed, the grounding line selection is started. For various single-phase earth faults, three algorithms are started simultaneously, and the system can select an earth line according to the characteristics of an earth signal by adopting a proper line selection algorithm in a targeted manner.
In step S100 of some embodiments of the present invention, the zero sequence voltages and zero sequence currents of the plurality of buses and the plurality of branches corresponding to each bus before and after the fault are obtained in real time. Specifically, the current data in the above period of time may be understood as a signal or a waveform, and thus the above current data may be processed by a waveform or a signal processing method; and acquiring zero sequence current according to a preset time interval and step length. For example, the board card can be flexibly configured through 60-way opening and 48-way opening (including 5-way hard contact alarm opening). The collecting or positioning device has the action modes of line selection tripping, wheel cutting, post acceleration and the like, so that the fault line is ensured to be rapidly and accurately cut off, and the further expansion of accidents is prevented. The device has the functions of multipoint ground fault identification, intermittent ground fault identification, fault type identification (distinguishing resistors and arc ground), fault statistics and the like, and provides data support for operation and maintenance of the power distribution network.
In step S200 of some embodiments of the present invention, the determining whether each branch is the first fault line according to the zero-sequence current and the zero-sequence voltage of each branch and the fundamental phases corresponding to the zero-sequence current and the zero-sequence voltage includes:
s201, determining three branches with the largest current amplitude change, and judging whether each branch is a first fault line according to zero flow and zero voltage of the three branches and respective fundamental wave phases;
s202, constructing differential current and braking current according to zero sequence currents of all branches of the same-section bus, and judging whether each branch is a first fault branch or not by adopting a ratio braking principle.
Further, in step S201, the determining whether each branch is the first fault line according to the zero flows and the zero voltages of the three branches and the respective fundamental phases includes: comparing the zero flow and zero voltage of the three branches and the respective fundamental wave phases, and judging the branch as a first fault line if any branch meets any one of the following conditions: zero flow of the branch with the largest zero flow amplitude is delayed by 90 degrees or is opposite to zero flow of the other two branches; zero flow of the branch with the largest amplitude change is delayed by 90 degrees or is opposite to zero flow of the other two branches.
It can be appreciated that the zero sequence power direction: and when the bus zero sequence voltage leads the zero sequence current (the maximum sensitive angle is 90 degrees and the action range is 150 degrees) of a certain circuit of the bus of the same section, judging the circuit as a grounding circuit.
Optionally, the method for positioning the ground fault based on the ratio brake characteristic comprises: and constructing differential current and braking current according to zero sequence currents of all branches of the same-section bus, and accurately positioning whether a fault point is on a branch of the section bus by adopting a ratio braking principle.
The ratio braking principle is that the operating current of the relay automatically increases with an increase in the external short-circuit current, and the operating current increases faster than the unbalanced current. Basic principle of ratio brake type current protection: the sum of all currents flowing into and out of the bus bar in the case of an internal fault is not zero. Thus: differential protection can correctly distinguish between internal and external faults of the bus. Bus differential protection with ratio braking characteristics introduces two main quantities: reflecting the operation amount of the differential current and reflecting the braking amount of the crossing current at the time of external short circuit. The calculation formula is as follows:
action amount:，
the braking amount is as follows:，
wherein i1, i2, & in represents the current of each branch; the criteria are as follows:,
,/>and->Representing the automatic coefficient and differential current thresholds (thresholds), respectively.
Referring to fig. 3 and 4, in step S300 of some embodiments of the present invention, the second criterion includes:
s301, calculating Lyapunov indexes of zero-sequence current or zero-sequence voltage after filtering of each branch by a Longgugar tower method;
s302, judging whether each branch has faults or not based on the Lyapunov exponent: if the Lyapunov exponent of a certain branch is larger than a preset value, judging that the branch has faults.
Further, in step S301, the calculating the lyapunov exponent of the filtered zero sequence current or zero sequence voltage by the longlattice tower method includes: acquiring circuit parameters of a plurality of branches corresponding to each bus, and determining a dynamic equation of a circuit model according to the circuit parameters of the plurality of branches and the filtered zero sequence current data; calculating the track of the dynamic equation by a Dragon-Gregory tower method; the Lyapunov exponent is calculated from the Wolf method and the trajectory of the dynamic equation.
Specifically, by the longgrid tower method, calculating the trajectory of the dynamic equation includes: calculating a jacobian matrix of the dynamic equation based on a line model; and calculating the track of the dynamic equation according to a preset boundary condition and the jacobian matrix.
Then, based on the physical characteristics of the grid, such as resistance, inductance, capacitance, generator dynamics, etc., related differential equations are established, which are typically nonlinear. Discretization time: selecting a proper time step according to the required precision and the characteristics of the power gridTo discretize the time. Wherein the jacobian matrix is expressed as:
，
f represents a waveform function of the power grid, X represents a state vector, and n represents a vector magnitude. x (t): is a state vector of the power grid and may include the following parameters: x is x 1 (t): the voltage of a certain node. X is X 2 (t): the voltage of the other node. X is X 3 (t): zero sequence current of a certain node.
The differential equation is approximately solved using the Runge-Kutta method, particularly the conventional fourth-order Runge-Kutta method. The method mainly carries out four estimations on the current state of the differential equation, and then updates the state by using the four estimations. And (3) iteration solution: starting from a certain initial state, the state of the system at each time step is obtained by utilizing a Runge-Kutta method to carry out stepwise iterative solution, so as to obtain the track of the system.
Alternatively, the Lyapunov exponent is calculated based on the Wolf method and the trajectory of the dynamic equation.
First, a reference trace point of the grid state is selected, and then the nearest neighbors thereof are found in the time series. The distance between the reference point and its neighboring frame at the next time step is calculated.
Repeating the steps to obtain the average index increase rate, namely the Lyapunov index.
Alternatively, the Lyapunov exponent is calculated using the Rosenstein method: an average period of the time series is estimated and an average distance of each pair of neighbors is calculated. The logarithmic growth rate of the distance over time is the Lyapunov exponent.
Alternatively, the Kantz method is used: similar to the Wolf method, but taking into account the entire future trajectory of the reference trajectory point and its neighbors, not just the next time step.
Finally, average and verify: in order to improve accuracy and robustness, the lyapunov exponent obtained by the above method may be averaged and the reliability verified by comparing the results obtained by different methods.
Optionally, in step S302, the visible proby filtering algorithm is replaced with extracting transient features based on infinite impulse filtering: and extracting transient characteristics of the zero-sequence voltage and the zero-sequence current through an infinite pulse filtering algorithm, and then calculating transient zero-sequence power of each branch, wherein the directions of the transient zero-sequence power of the fault branch and the transient zero-sequence power of the non-fault branch are opposite.
It can be understood that the decomposition of the zero sequence current mutation waveform by the wavelet packet filtering algorithm is used for judging whether each branch is a fault line. In step S400 of some embodiments of the present invention, the third criterion includes: s401, determining a decomposition order and an energy entropy of wavelet packet transformation based on Hilbert transformation; s402, decomposing the zero sequence current mutation waveform through a wavelet packet filtering algorithm according to the decomposition order and the energy entropy to obtain a fundamental wave and a plurality of harmonic waves;
s403, judging whether each branch is a third fault line according to the amplitude, the phase and the energy entropy of the fundamental wave and the harmonic wave.
In step S500 of some embodiments of the present invention, the fault line of each bus is comprehensively determined by the first criterion, the second criterion and the third criterion based on the analytic hierarchy process or the bayesian probability.
Specifically, when the judging results of the first criterion, the second criterion and the third criterion are consistent, constructing a hierarchical matrix or a judging matrix according to a hierarchical analysis method, and determining the weight of each criterion according to the probability of occurrence of various faults; if the results of the first criterion, the second criterion and the third criterion are inconsistent, one of the criteria is used as a condition, the fault probability determined by the other two criteria is calculated according to the Bayesian probability, and the criterion of the maximum probability is taken as the optimal result.
It can be understood that the first criterion, the second criterion, the third criterion can be deleted or expanded according to the fundamental wave criterion, the transient criterion and the like, so as to improve the accuracy and the robustness of judgment.
Example 2
Referring to fig. 5, in a second aspect of the present invention, there is provided a single-phase earth fault locating device 1 for a power distribution network based on multiple criteria, including: the acquisition module 11 is used for acquiring zero sequence voltages and zero sequence currents of the buses and the corresponding branches before and after the fault in real time; a first criterion module 12, configured to determine a first criterion based on the zero sequence current and the zero sequence voltage of each branch and the fundamental wave phase corresponding to the zero sequence current and the zero sequence voltage; the second criterion module 13 is used for extracting transient characteristics of the zero sequence voltage and the zero sequence current based on a prony filtering algorithm and determining a second criterion; a third criterion module 14, configured to determine a third criterion based on the zero sequence current mutation waveform and the wavelet packet filtering algorithm of each branch in the bus; the judging module 15 is configured to comprehensively judge the fault line of each bus through the first criterion, the second criterion and the third criterion based on the analytic hierarchy process or the bayesian probability.
Further, the first judging module 12 includes: the determining unit is used for determining three branches with the largest current amplitude change and judging whether each branch is a first fault line according to zero flow and zero voltage of the three branches and respective fundamental wave phases; and the judging unit is used for constructing differential current and braking current according to zero sequence current of all the branches of the same-section bus and judging whether each branch is a first fault branch or not by adopting a ratio braking principle.
Example 3
Referring to fig. 6, a third aspect of the present invention provides an electronic device, including: one or more processors; and storage means for storing one or more programs which, when executed by the one or more processors, cause the one or more processors to implement the method of the present invention in the first aspect.
The electronic device 500 may include a processing means (e.g., a central processing unit, a graphics processor, etc.) 501 that may perform various appropriate actions and processes in accordance with programs stored in a Read Only Memory (ROM) 502 or loaded from a storage 508 into a Random Access Memory (RAM) 503. In the RAM 503, various programs and data required for the operation of the electronic apparatus 500 are also stored. The processing device 501, the ROM 502, and the RAM 503 are connected to each other via a bus 504. An input/output (I/O) interface 505 is also connected to bus 504.
The following devices may be connected to the I/O interface 505 in general: input devices 506 including, for example, a touch screen, touchpad, keyboard, mouse, camera, microphone, accelerometer, gyroscope, etc.; an output device 507 including, for example, a Liquid Crystal Display (LCD), a speaker, a vibrator, and the like; storage 508 including, for example, a hard disk; and communication means 509. The communication means 509 may allow the electronic device 500 to communicate with other devices wirelessly or by wire to exchange data. While fig. 6 shows an electronic device 500 having various means, it is to be understood that not all of the illustrated means are required to be implemented or provided. More or fewer devices may be implemented or provided instead. Each block shown in fig. 6 may represent one device or a plurality of devices as needed.
In particular, according to embodiments of the present disclosure, the processes described above with reference to flowcharts may be implemented as computer software programs. For example, embodiments of the present disclosure include a computer program product comprising a computer program embodied on a computer readable medium, the computer program comprising program code for performing the method shown in the flowcharts. In such an embodiment, the computer program may be downloaded and installed from a network via the communication means 509, or from the storage means 508, or from the ROM 502. The above-described functions defined in the methods of the embodiments of the present disclosure are performed when the computer program is executed by the processing device 501. It should be noted that the computer readable medium described in the embodiments of the present disclosure may be a computer readable signal medium or a computer readable storage medium or any combination of the two. The computer readable storage medium can be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or a combination of any of the foregoing. More specific examples of the computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In an embodiment of the present disclosure, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. Whereas in embodiments of the present disclosure, the computer-readable signal medium may comprise a data signal propagated in baseband or as part of a carrier wave, with computer-readable program code embodied therein. Such a propagated data signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination of the foregoing. A computer readable signal medium may also be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to: electrical wires, fiber optic cables, RF (radio frequency), and the like, or any suitable combination of the foregoing.
The computer readable medium may be contained in the electronic device; or may exist alone without being incorporated into the electronic device. The computer readable medium carries one or more computer programs which, when executed by the electronic device, cause the electronic device to:
computer program code for carrying out operations of embodiments of the present disclosure may be written in one or more programming languages, including an object oriented programming language such as Java, smalltalk, C ++, python and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any kind of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computer (for example, through the Internet using an Internet service provider).
The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
The foregoing description of the preferred embodiments of the invention is not intended to limit the invention to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and scope of the invention are intended to be included within the scope of the invention.
Claims (10)
1. A method for locating single-phase earth faults of a power distribution network based on multiple criteria is characterized by comprising the following steps:
acquiring zero sequence voltages and zero sequence currents of a plurality of buses and a plurality of branches corresponding to each bus before and after a fault in real time;
determining a first criterion based on the zero sequence current, the zero sequence voltage and the fundamental wave phase corresponding to the zero sequence current and the zero sequence voltage of each branch;
extracting transient characteristics of the zero sequence voltage and the zero sequence current based on a prony filtering algorithm, and determining a second criterion;
determining a third criterion based on zero sequence current mutation quantity waveforms and wavelet packet filtering algorithm of each branch in the bus;
based on analytic hierarchy process or Bayesian probability, comprehensively judging the fault line of each bus through the first criterion, the second criterion and the third criterion.
2. The multi-criterion based single-phase earth fault location method of a power distribution network of claim 1, wherein the first criterion comprises:
determining three branches with the largest current amplitude change, and judging whether each branch has faults or not according to zero flows and zero pressures of the three branches and respective fundamental wave phases;
and constructing differential current and braking current according to zero sequence currents of all branches of the same-section bus, and judging whether each branch has faults or not by adopting a ratio braking principle.
3. The method for locating single-phase earth faults of a power distribution network based on multiple criteria according to claim 2, wherein the constructing differential current and braking current according to zero sequence current of all branches of the same-section bus, and judging whether each branch has faults by adopting a ratio braking principle comprises:
determining differential current and braking current of the same-section bus, and determining an action equation according to the differential current and the braking current;
and judging whether each branch has faults or not based on the action equation.
4. The multi-criterion based single-phase earth fault location method of a power distribution network of claim 1, wherein the second criterion comprises:
calculating the Lyapunov exponent of the zero sequence current or zero sequence voltage after each branch is filtered by a LongGregory tower method;
judging whether each branch has faults or not based on the Lyapunov exponent: if the Lyapunov exponent of a certain branch is larger than a preset value, judging that the branch has faults.
5. The multi-criterion based single-phase earth fault location method of power distribution network according to claim 4, wherein calculating the lyapunov exponent of the filtered zero sequence current or zero sequence voltage by the longgnus tower method comprises:
acquiring circuit parameters of a plurality of branches corresponding to each bus, and determining a dynamic equation of a circuit model according to the circuit parameters of the plurality of branches and the filtered zero sequence current data;
calculating the track of the dynamic equation by a Dragon-Gregory tower method;
the Lyapunov exponent is calculated from the Wolf method and the trajectory of the dynamic equation.
6. The multi-criterion based single-phase earth fault location method of a power distribution network of claim 1, wherein the third criterion comprises:
determining a decomposition order and an energy entropy of a wavelet packet transform based on the Hilbert transform;
according to the decomposition order and the energy entropy, decomposing the zero sequence current mutation quantity waveform through a wavelet packet filtering algorithm to obtain a fundamental wave and a plurality of harmonic waves;
judging whether each branch has faults or not according to the amplitude, the phase and the energy entropy of the fundamental wave and the harmonic wave.
7. A multi-criterion-based single-phase earth fault locating device for a power distribution network, comprising:
the acquisition module is used for acquiring the zero sequence voltage and the zero sequence current of the buses and the corresponding branches before and after the fault in real time;
the first criterion module is used for determining a first criterion based on the zero sequence current and the zero sequence voltage of each branch and the fundamental wave phase corresponding to the zero sequence current and the zero sequence voltage;
the second criterion module is used for extracting transient characteristics of the zero sequence voltage and the zero sequence current based on a prony filtering algorithm and determining a second criterion;
the third criterion module is used for determining a third criterion based on the zero sequence current mutation quantity waveform and the wavelet packet filtering algorithm of each branch in the bus;
the judging module is used for comprehensively judging the fault line of each bus through the first criterion, the second criterion and the third criterion based on the analytic hierarchy process or the Bayesian probability.
8. The multi-criterion based single-phase earth fault locating device of a power distribution network of claim 7, wherein the first criterion module comprises:
the determining unit is used for determining three branches with the largest current amplitude change and judging whether each branch is a first fault line according to zero flow and zero voltage of the three branches and respective fundamental wave phases;
and the judging unit is used for constructing differential current and braking current according to zero sequence current of all the branches of the same-section bus and judging whether each branch is a first fault branch or not by adopting a ratio braking principle.
9. An electronic device, comprising: one or more processors; storage means for storing one or more programs which when executed by the one or more processors cause the one or more processors to implement the multi-criterion based single phase earth fault localization method of a power distribution network as claimed in any one of claims 1 to 6.
10. A computer readable medium having stored thereon a computer program, wherein the computer program when executed by a processor implements a multi-criterion based single phase earth fault localization method of a power distribution network as claimed in any one of claims 1 to 6.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117590282A (en) * | 2024-01-19 | 2024-02-23 | 武汉格蓝若智能技术股份有限公司 | Ground fault parameter identification sensor and line selection method thereof |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101022216A (en) * | 2007-02-07 | 2007-08-22 | 燕山大学 | Small earthing current electric network single phase fault wire selecting method and apparatus |
| CN102654553A (en) * | 2012-05-07 | 2012-09-05 | 河南省电力公司南阳供电公司 | Method for line selection and positioning |
| US20160041216A1 (en) * | 2013-03-29 | 2016-02-11 | Beijing Inhand Networks Technology Co., Ltd. | Method and system for detecting and locating single-phase ground fault on low current grounded power-distribution network |
| CN105974254A (en) * | 2016-05-16 | 2016-09-28 | 国网江苏省电力公司连云港供电公司 | Transient and steady state line selection method based on voltage calculation comprehensive weight |
| CN110596530A (en) * | 2019-09-06 | 2019-12-20 | 国网山东省电力公司寿光市供电公司 | Low-current ground fault line selection method |
| CN110687395A (en) * | 2019-09-23 | 2020-01-14 | 南京理工大学 | Fault line selection method for power distribution network with distributed power supply based on deep belief network |
| CN111929611A (en) * | 2020-07-20 | 2020-11-13 | 南方电网科学研究院有限责任公司 | Distribution line ground fault positioning method and system based on zero-mode current difference |
| CN112255493A (en) * | 2020-09-07 | 2021-01-22 | 西安理工大学 | Multi-criterion comprehensive voting power distribution network fault line selection method |
| US20210382103A1 (en) * | 2018-11-01 | 2021-12-09 | University Of Manitoba | Method for Determining Conductors Involved in a Fault on a Power Transmission Line and Fault Location Using Local Current Measurements |
| WO2022121138A1 (en) * | 2020-12-09 | 2022-06-16 | 山东大学 | Method and system for high-resistance fault line selection and segment localization in resonant grounding system |
| CN116482571A (en) * | 2023-05-10 | 2023-07-25 | 云南电网有限责任公司红河供电局 | CNN-based low-current single-phase earth fault multi-criterion fusion line selection method |
| CN116609610A (en) * | 2023-05-05 | 2023-08-18 | 天津大学 | Single-phase earth fault phase selection method based on self-adaptive wavelet packet transformation |
| CN116908605A (en) * | 2023-04-27 | 2023-10-20 | 国网浙江省电力有限公司瑞安市供电公司 | Fault line identification method, device, terminal and medium based on transient small current |
-
2023
- 2023-10-23 CN CN202311373798.XA patent/CN117110797B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101022216A (en) * | 2007-02-07 | 2007-08-22 | 燕山大学 | Small earthing current electric network single phase fault wire selecting method and apparatus |
| CN102654553A (en) * | 2012-05-07 | 2012-09-05 | 河南省电力公司南阳供电公司 | Method for line selection and positioning |
| US20160041216A1 (en) * | 2013-03-29 | 2016-02-11 | Beijing Inhand Networks Technology Co., Ltd. | Method and system for detecting and locating single-phase ground fault on low current grounded power-distribution network |
| CN105974254A (en) * | 2016-05-16 | 2016-09-28 | 国网江苏省电力公司连云港供电公司 | Transient and steady state line selection method based on voltage calculation comprehensive weight |
| US20210382103A1 (en) * | 2018-11-01 | 2021-12-09 | University Of Manitoba | Method for Determining Conductors Involved in a Fault on a Power Transmission Line and Fault Location Using Local Current Measurements |
| CN110596530A (en) * | 2019-09-06 | 2019-12-20 | 国网山东省电力公司寿光市供电公司 | Low-current ground fault line selection method |
| CN110687395A (en) * | 2019-09-23 | 2020-01-14 | 南京理工大学 | Fault line selection method for power distribution network with distributed power supply based on deep belief network |
| CN111929611A (en) * | 2020-07-20 | 2020-11-13 | 南方电网科学研究院有限责任公司 | Distribution line ground fault positioning method and system based on zero-mode current difference |
| CN112255493A (en) * | 2020-09-07 | 2021-01-22 | 西安理工大学 | Multi-criterion comprehensive voting power distribution network fault line selection method |
| WO2022121138A1 (en) * | 2020-12-09 | 2022-06-16 | 山东大学 | Method and system for high-resistance fault line selection and segment localization in resonant grounding system |
| CN116908605A (en) * | 2023-04-27 | 2023-10-20 | 国网浙江省电力有限公司瑞安市供电公司 | Fault line identification method, device, terminal and medium based on transient small current |
| CN116609610A (en) * | 2023-05-05 | 2023-08-18 | 天津大学 | Single-phase earth fault phase selection method based on self-adaptive wavelet packet transformation |
| CN116482571A (en) * | 2023-05-10 | 2023-07-25 | 云南电网有限责任公司红河供电局 | CNN-based low-current single-phase earth fault multi-criterion fusion line selection method |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117590282A (en) * | 2024-01-19 | 2024-02-23 | 武汉格蓝若智能技术股份有限公司 | Ground fault parameter identification sensor and line selection method thereof |
| CN117590282B (en) * | 2024-01-19 | 2024-05-31 | 武汉格蓝若智能技术股份有限公司 | Ground fault parameter identification sensor and line selection method thereof |
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|---|---|
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