KR101717223B1 - On-line Remote Diagnosis System for DC Bus Capacitor of Power Converters Using Zigbee Communication and method thereof - Google Patents
On-line Remote Diagnosis System for DC Bus Capacitor of Power Converters Using Zigbee Communication and method thereof Download PDFInfo
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- KR101717223B1 KR101717223B1 KR1020150072007A KR20150072007A KR101717223B1 KR 101717223 B1 KR101717223 B1 KR 101717223B1 KR 1020150072007 A KR1020150072007 A KR 1020150072007A KR 20150072007 A KR20150072007 A KR 20150072007A KR 101717223 B1 KR101717223 B1 KR 101717223B1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R22/00—Arrangements for measuring time integral of electric power or current, e.g. electricity meters
- G01R22/06—Arrangements for measuring time integral of electric power or current, e.g. electricity meters by electronic methods
- G01R22/061—Details of electronic electricity meters
- G01R22/063—Details of electronic electricity meters related to remote communication
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- G01R31/028—
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- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B21/00—Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
- G08B21/18—Status alarms
- G08B21/185—Electrical failure alarms
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- G—PHYSICS
- G08—SIGNALLING
- G08C—TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
- G08C17/00—Arrangements for transmitting signals characterised by the use of a wireless electrical link
- G08C17/02—Arrangements for transmitting signals characterised by the use of a wireless electrical link using a radio link
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- G—PHYSICS
- G08—SIGNALLING
- G08C—TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
- G08C19/00—Electric signal transmission systems
- G08C19/02—Electric signal transmission systems in which the signal transmitted is magnitude of current or voltage
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- Inverter Devices (AREA)
- Testing Electric Properties And Detecting Electric Faults (AREA)
Abstract
The present invention processes a specific switching frequency in real time for each power conversion device by using a simple method of estimating the ESR from the loss of AC power after signal processing process of the AC coupling to the ripple voltage and current component of the capacitor The present invention relates to an on-line remote fault diagnosis system for a DC-bus capacitor of a power conversion device using a Zigbee communication, and is provided with a power conversion system, A DC bus capacitor failure detecting device for outputting the result; And an ESR monitoring and analysis device for monitoring and monitoring the state of the DC bus capacitor based on the ESR value estimated from the DC bus capacitor failure detection device and outputting a failure notification message to the outside when the DC bus capacitor fails in the analysis result . Accordingly, it is possible to realize a real-time implementation by a simple method of estimating the ESR from the loss of AC power after signal processing process of the AC coupling with the ripple voltage and current component of the capacitor.
Description
The present invention relates to a system and method for on-line remote fault diagnosis of a DC-bus capacitor of a power conversion device using Zigbee communication. More particularly, the present invention relates to a system and method for on-line remote fault diagnosis of a DC- A simple method of estimating ESR (Equivalent Series Resistance, hereinafter abbreviated as "ESR") from a loss of AC power after the process is performed, To a system and method for on-line remote fault diagnosis of a DC-bus capacitor of a power conversion device using Zigbee communication.
The development of power electronics technologies based on power semiconductor devices and embedded systems has led to a surge in the use of nonlinear loads, such as increased use of custom power conversion devices.
This is exemplified not only by increasing the capacity of various power conversion devices, but also by the surge of inverter use such as variable speed drive of motors, expansion of new renewable energy equipment, and continuous use of nonlinear loads such as SMPS.
In this power conversion device, a large capacity electrolytic capacitor is used in the DC Bus stage to store DC energy, to reduce the switching ripple current, and to smooth the voltage. However, such a DC electrolytic capacitor is accompanied by an increase in the period of use, an increase in the evaporation, deterioration, and loss increase of the electrolyte due to a rise in temperature, leading to an accident of explosion, thereby remarkably lowering the operational reliability of the apparatus.
The failure of the DC capacitor can be a risk factor not only for simple parts accident of the DC Bus but also for the power system accident. Therefore, it is necessary to develop a diagnosis system that can prevent this.
So far, fault diagnosis techniques for electrolytic capacitors have been based on the ESR value estimation method of capacitors. Most of the fault diagnosis techniques that judge the start of abnormality when the degradation of the capacitor is about twice the normal value do. As a concrete estimation technique of this, Afroz M. Imam preferred the indirect estimation technique using frequency analysis. This method estimates the ESR as a result of the FFT analysis after passing the voltage / current signal of the capacitor ripple component in the DC / DC converter model through the signal processing (band pass filter) in the specific switching frequency domain. However, this method has a problem that it is difficult to process in real time online.
In order to solve such a problem, the present invention provides a method of estimating the ESR from the loss of AC power after signal processing of the AC coupling by using the pulsating voltage and the current component of the capacitor, And an object of the present invention is to provide a system and method for on-line remote fault diagnosis of a DC-bus capacitor of a power conversion apparatus using Zigbee communication that can process a switching frequency of the DC-
The on-line remote fault diagnosis system of the DC-bus capacitor of the power conversion apparatus using the Zigbee communication according to the embodiment of the present invention is provided in the power conversion system, and based on the power loss of the DC-bus capacitor included in the power conversion system, A DC-bus capacitor failure detecting device for estimating an output of the DC-bus capacitor; And an ESR monitoring and analysis device for monitoring and monitoring the state of the DC bus capacitor based on the ESR value estimated from the DC bus capacitor failure detection device and outputting a failure notification message to the outside when the DC bus capacitor fails in the analysis result .
The on-line remote fault diagnosis system of the DC-bus capacitor of the power conversion apparatus using Zigbee communication according to another embodiment of the present invention is provided in the power conversion system, and based on the power loss of the DC-bus capacitor included in the power conversion system DC bus capacitor failure detecting devices for estimating an ESR, matching an ESR estimation result value with identification information (ID), and outputting the result; And an ESR value matching the identification information (ID) output from the DC bus capacitor failure detecting devices, and stores the estimated ESR value in correspondence with the identification information (ID), and based on the estimated ESR value, And an ESR monitoring and analyzing apparatus for monitoring and analyzing the state of the DC bus capacitor and outputting a failure notification message to the outside when an abnormality occurs in the DC bus capacitor.
As an embodiment related to the present invention, the DC-bus capacitor failure detecting device and the ESR monitoring and analyzing device each include a Zigbee communication module, and the ESR value can be mutually transmitted and received through the Zigbee communication module.
As an embodiment related to the present invention, a DC-bus capacitor failure detecting apparatus includes a ripple voltage detecting unit connected to both (+) and (-) terminals of a DC-bus capacitor and detecting a ripple voltage of the DC-bus capacitor, A ripple current detector for detecting a ripple current of the DC bus capacitor; and a control unit for calculating a power loss using the ripple voltage detected by the ripple voltage detector and the ripple current detected by the ripple current detector, And an ESR estimating unit for estimating and outputting an ESR based on the power loss calculated by the power loss calculating unit.
As an embodiment related to the present invention, the ESR monitoring and analyzing apparatus determines whether or not the ID exceeds the set maximum value, and if the ID is exceeded, the ID is initialized and the status result value of the DC bus capacitor is received .
An on-line remote fault diagnosis method of a DC-bus capacitor of a power conversion apparatus using Zigbee communication according to an embodiment of the present invention is characterized in that the ESR monitoring and analyzing apparatus includes a step of reading predetermined setting values; Wherein the ESR monitoring and analyzing apparatus comprises: initializing a Zigbee communication module; The ESR monitoring and analysis apparatus requesting the transfer of the status result value of the measured DC bus capacitor; Wherein the ESR monitoring and analyzing device checks whether a status result value of the DC bus capacitor is received and determines whether the status result value is received; The ESR monitoring and analyzing apparatus reads the ripple voltage, the ripple current, and the ESR estimated value from the resultant value of the received DC-bus capacitor and stores it in the storage unit; The ESR monitoring and analyzing device checks whether the DC bus capacitor is faulty based on the ESR estimation value. If the DC bus capacitor is normal, it increases the ID for matching the status result value. If it is determined that the DC bus capacitor is abnormal, ; The ESR monitoring and analyzing apparatus determines whether or not the increased ID exceeds the set maximum value. If the ID is exceeded, the ESR monitoring and analyzing apparatus returns to the step of receiving the status result value of the DC bus capacitor after initializing the ID, And if it does not exceed the value, the step of receiving the status result of the DC-bus capacitor may be repeated.
The present invention has the effect of realizing a real-time implementation in a simple way of estimating the ESR from the loss of its AC power after signal processing the AC-coupled pulse voltage and current component of the capacitor.
In addition, the present invention uses a module of Zigbee wireless communication method which has advantages of low power and low price, and the adoption of main MCU is STM32F series which is a 32 bit device of ST Microelectronics based on ARM Cortex-M3 which is a low- So that the system can be implemented at a low cost.
1 is a view for explaining a structure of an electrolytic capacitor and an electrolyte leakage path.
2 is a failure mode analysis diagram of an electrolytic capacitor.
3 is a diagram for explaining an on-line remote fault diagnosis system of a DC-bus capacitor of a power conversion device using Zigbee communication according to the present invention.
4 is a circuit diagram schematically showing an ESR failure detection method according to the present invention.
Fig. 5 is another embodiment of Fig.
6 is a flowchart illustrating an on-line remote fault diagnosis method for a DC-bus capacitor of a power conversion apparatus using Zigbee communication according to the present invention.
It is noted that the technical terms used in the present invention are used only to describe specific embodiments and are not intended to limit the present invention. In addition, the technical terms used in the present invention should be construed in a sense generally understood by a person having ordinary skill in the art to which the present invention belongs, unless otherwise defined in the present invention, Should not be construed to mean, or be interpreted in an excessively reduced sense. In addition, when a technical term used in the present invention is an erroneous technical term that does not accurately express the concept of the present invention, it should be understood that technical terms can be understood by those skilled in the art. In addition, the general terms used in the present invention should be interpreted according to a predefined or prior context, and should not be construed as being excessively reduced.
Furthermore, the singular expressions used in the present invention include plural expressions unless the context clearly dictates otherwise. In the present invention, terms such as "comprising" or "comprising" and the like should not be construed as encompassing various elements or stages of the invention, Or may further include additional components or steps.
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like or similar elements throughout the several views, and redundant description thereof will be omitted.
FIG. 1 is a view for explaining the structure of an electrolytic capacitor and an electrolyte leakage path, in which the load of a power electronic device, that is, the continuous use of a nonlinear load, is increased by a DC bus for AC / DC coupling and voltage smoothing, ) Means increasing the use of electrolytic capacitors. Low-cost, low-cost aluminum electrolytic capacitors are mainly used for DC-bus capacitors. High purity aluminum foil is used for the aluminum electrolytic capacitor electrode and a thin oxide film is used for the dielectric. An anode foil, which is a (+) electrode, forms a dielectric oxide film (Al 2 O 3 ) on the surface, and the (-) electrode of the cathode is etched to enlarge the surface area. Between the two electrodes is composed of an electrolytic solution and electrolytic solution.
Fig. 1 (a) is a view showing the structure of an aluminum electrolytic capacitor, Fig. 1 (b) is a view for explaining a diffusion path for evaporation of a capacitor electrolytic solution by three routes, (2) is the passage between the sealing rubber and the lead wire gap, and (3) is the passage between the sealing rubber and the aluminum case gap.
FIG. 2 is a failure mode analysis diagram of the electrolytic capacitor. The failure mode of the electrolytic capacitor can be largely divided into electrical performance deterioration and mechanical failure. The mechanical failure can be represented by a short circuit and an open circuit, and an open circuit rarely occurs in a faulty circuit connection, and the short circuit is caused by shorting of the electrode or dielectric breakdown of the oxide film or insulating paper as shown in FIG.
The deterioration of electrical performance is mostly due to the electrochemical reaction, that is, the evaporation of the electrolyte due to the temperature rise. This is caused by a decrease in electrolyte, an ejection of electrolyte vapor, and a decrease in capacitance, which are caused by excessive temperature, voltage, and ripple current (ripple current). In particular, the excess of temperature is directly related to electrolyte performance and increases the temperature rise due to the increase of ripple current (ripple current).
Also, the reverse voltage of the capacitor, the number of charge / discharge duty cycles, and the ripple current (pulsating current) exceed the dielectric constant due to the decrease of the capacitance due to the electrochemical reaction (tan delta) Resulting in an increase in leakage current. Since the aluminum electrolytic capacitor uses the electrolytic solution in this way, the electrolytic solution evaporates after a lapse of time, and the characteristic defects gradually appear due to the temperature and deterioration. This leads to a decrease in capacitance and an increase in ESR, thereby forming a deterioration failure mode.
( Example 1 )
3 is a diagram for explaining an on-line remote fault diagnosis system of a DC-bus capacitor of a power conversion device using Zigbee communication according to the present invention.
3, an on-line remote fault diagnosis system for a DC-bus capacitor of a power conversion apparatus using ZigBee communication to which the present invention is applied includes a DC-bus capacitor
A DC-bus capacitor failure detecting apparatus (100) is provided in a power conversion system, estimates an ESR based on a power loss of a DC-bus capacitor provided in the power conversion system, and outputs the result.
The DC bus capacitor
The ESR monitoring and analyzing
The DC-bus capacitor
FIG. 4 is a circuit diagram schematically illustrating an ESR failure detection method according to the present invention. The complex impedance is greatly changed in accordance with the frequency variation of the input, and the impedance value within the range of the use of the switching frequency is It is very dominant in the ESR value inside the electrolytic capacitor. Therefore, the fault signal detection technique of most electrolytic capacitors is performed by measuring its ESR.
The fault diagnosis of the electrolytic capacitor can be calculated from the total AC average power loss for the electrolytic capacitor, and the ESR value of the capacitor is estimated from the calculated result by the procedure shown in FIG. The pulsating current I C for a DC bus electrolytic capacitor of a power conversion device such as an inverter or a converter shown in FIG. 4 is generally expressed as a current I C of a DC component, a current I C of a DC component, C, and AC , which are shown in Equation (1).
When the ripple current signal of the converter is signaled by AC coupling, it is an open circuit for the DC source. Therefore , only the current (I C, AC ) component of the AC component of the electrolytic capacitor appears on the capacitor do. This can estimate the ESR by blocking the DC component and determining the AC power loss only by the signal of the AC coupling component.
That is, the RESR is calculated by
Therefore, the instantaneous power losses P C, AC (V C, AC I C, AC ) and (I C, AC ) 2 ? Pass filter (LPF) to obtain signals of P C, F and (I C, F ) 2 , and it is possible to easily estimate the RESR average value using Equation (2). Since the average value of the RESR thus obtained is limited by the low-pass filter (LPF) and the high-frequency component by the AC coupling, the conventional band-pass filtering It is easier to implement.
A detailed description of the interaction of the respective components will be given in the second embodiment.
( Example 2 )
Fig. 5 is another embodiment of Fig.
As shown in FIG. 5, the on-line remote fault diagnosis system for a DC-bus capacitor of a power conversion apparatus using Zigbee communication according to another embodiment of the present invention includes a plurality of DC-bus capacitor
A plurality of DC-bus capacitor
The ESR monitoring and analyzing
The DC-bus capacitor
The configuration of the DC-bus capacitor
The detailed description of the DC-bus capacitor
The ESR monitoring and analyzing
An on-line remote fault diagnosis method of the DC-bus capacitor of the power conversion apparatus using the Zigbee communication will be described below.
6 is a flowchart illustrating an on-line remote fault diagnosis method for a DC-bus capacitor of a power conversion apparatus using Zigbee communication according to the present invention.
As shown in FIG. 6, the ESR monitoring and
The ESR monitoring and analyzing
The ESR monitoring and analyzing
Then, the ESR monitoring and analyzing
The ESR monitoring and analyzing
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or essential characteristics thereof. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.
100: DC bus capacitor failure detection device
110: DC bus capacitor 120: ripple voltage detector
130: power
150: ripple current detection unit 160: ripple current calculation unit
180: ESR estimating unit
200: ESR monitoring and analysis device
Claims (6)
The ESR value matching the identification information (ID) from the DC bus capacitor failure detecting devices is received and stored, and the ESR value is matched to the identification information (ID), and the stored ESR value is stored on the basis of the estimated ESR value. And an ESR monitoring and analyzing device for monitoring and analyzing the state of the DC bus capacitor and outputting a fault notification message to the outside when an abnormality occurs in the DC bus capacitor,
Wherein the ESR monitoring and analyzing apparatus determines whether or not the identification information (ID) has exceeded a set maximum value, and if the maximum value is exceeded, initializes the identification information (ID) And the remote fault diagnosis system of the DC-bus capacitor of the power conversion device using the Zigbee communication.
Wherein the ESR monitoring and analyzing apparatus comprises: initializing a ZigBee communication module;
The ESR monitoring and analyzing apparatus requesting the status result of the measured DC bus capacitor to be transmitted;
Wherein the ESR monitoring and analyzing unit checks whether a status result value of the DC bus capacitor is received and determines whether a status result value of the DC bus capacitor is received;
Wherein the ESR monitoring and analyzing apparatus reads the ripple voltage, the ripple current, and the ESR estimated value from the state result value of the received DC-bus capacitor and stores the ripple voltage, the ripple current, and the ESR estimated value in the storage unit;
The ESR monitoring and analyzing apparatus checks whether the DC bus capacitor is faulty based on the ESR estimation value and increases the ID for matching the status result value when the DC bus capacitor is normal. If it is determined that the DC bus capacitor is abnormal, Outputting;
The ESR monitoring and analyzing apparatus determines whether the increased ID exceeds a set maximum value, and when the maximum value is exceeded, the ESR monitoring and analyzing apparatus returns to the step of receiving a status result value of the DC bus capacitor after initializing the ID Repeating the step of receiving the status result value of the DC-bus capacitor when the maximum value is not exceeded;
And a third step of detecting the on-line remote fault of the DC-bus capacitor of the power conversion device using the Zigbee communication.
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CN106771783B (en) * | 2017-02-14 | 2023-08-18 | 英孚康(浙江)工业技术有限公司 | Health monitoring circuit of direct current bus capacitor bank |
CN109917222B (en) * | 2019-03-06 | 2020-12-18 | 湖北工业大学 | Device and method for comprehensive online monitoring and health state diagnosis of capacitor assembly |
CN112540223A (en) * | 2020-11-23 | 2021-03-23 | 珠海格力电器股份有限公司 | Intelligent ammeter and electricity taking method and device thereof |
CN114285164A (en) * | 2021-12-24 | 2022-04-05 | 江苏国科智能电气有限公司 | State monitoring method for direct-current bus capacitor of wind power converter based on variable discharge network |
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KR20100009191U (en) * | 2009-03-11 | 2010-09-24 | 손진근 | Real Time Fault Monitoring System of Electrolytic Capacitor for Power Conversion System |
KR101019342B1 (en) | 2009-05-04 | 2011-03-07 | 손진근 | Online Failure Detection System of DC Output Filtering Capacitors in Power Converters |
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