KR100961170B1 - Automatic diagnostic system for power electronics device - Google Patents

Abstract

The present invention relates to a power device automatic diagnosis system, and more particularly, to a power device automatic diagnosis system comprising an LCR metering unit for testing performance before power is supplied to each device constituting each power device module used in a power system, A switch box having a connection terminal and a plurality of switches for interrupting a power supply provided to each element through a connection terminal to check performance after power is supplied to each element; And the LCR metering unit controls the operation of the LCR metering unit to check the performance before power supply to each device and controls the switch box and the diagnosis unit so that the performance after each power supply And a control unit for controlling the control unit. This makes it possible to efficiently perform individual diagnosis and characteristic analysis of each power device of the voltage source inverter for maintenance of the FACTS facility. In addition, it enables diagnosis and characterization of power device valves as well as individual diagnosis and characterization of power devices, thereby maximizing maintenance efficiency and maximizing accuracy and reliability of voltage source inverter inspection. .

FACTS, power device valve, power device module, auto, diagnosis, LCR meter, switch box

Description

[0001] The present invention relates to an automatic diagnostic system for a power device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power device automatic diagnosis system, and more particularly, to a power device automatic diagnosis system that can automatically diagnose and characterize each power device module constituting a voltage source inverter of an FACTS facility.

The FACTS (Flexible AC Transmission System) facility is a power control facility that performs reactive power compensation, voltage control, tidal control, stability control, and power quality control of a power system using continuous and rapid power control characteristics of a large-capacity voltage source inverter. Since the FACTS facility was developed in the US in the early 1990s, the installation has been expanding globally. Currently, there are installed 154kV 80MVA UPFC in Gangjin substation and 345kV 100MVA STATCOM in Mingeum substation in Korea.

In order to maximize the utilization rate and operational reliability of such FACTS facilities, continuous maintenance is indispensable. In particular, continuous and periodic soundness diagnosis and precise characteristic analysis of the voltage source inverter, which is a core facility of the FACTS facility, are required. Since the voltage source inverter is composed of 5 to 8 electric power element valves connected in series such as GTO, IGBT, etc., diagnosis of each power element module and valve is required for analyzing characteristics of the voltage source inverter.

In the past, diagnosis and characterization were performed manually for each individual power device, which resulted in too much time for individual power device characteristics analysis, resulting in a significant reduction in maintenance efficiency. For example, an 80 MVA UPFC consists of two voltage source inverters. Each inverter consists of six inverter poles and one DC clamp circuit. Each pole and DC clamp circuit has four And two valves. At this time, each valve consists of five series-connected GTO power module. Therefore, each inverter consists of 120 GTO power devices (6 poles x 20 modules / pole) and 10 GTO power devices (2 x 5 modules) for DC clamps, thus having a total of 130 GTO modules.

However, in the conventional passive power module test analysis method for the maintenance of the FACTS voltage source inverter, the test is performed for the power device, the anti-parallel diode, and the snubber circuit, which are the power device modules, Device DC conduction test, Impedance test for RC elements, Power element conduction on-drop test after power-on test, On-Drop test for reverse parallel diode conduction are tested individually using test equipment such as oscilloscope and DC power supply. I'm doing it manually. Therefore, individual diagnosis and characterization of each power device module is very inefficient when there are many power device modules of the FACTS facility.

It is an object of the present invention to provide a power device automatic diagnosis system which can automatically diagnose and characterize each power device module constituting a voltage source inverter of an FACTS facility.

An object of the present invention is to provide an LCR metering unit for checking performance before power is supplied to each element constituting each power element module used in a power system; A plurality of connection terminals connected to both ends of each of the elements; A switch box having a plurality of switches for interrupting a power supply provided to each element through the connection terminal to check performance after power supply to each of the elements; A diagnostic unit for analyzing performance of each of the devices according to voltage and current values measured from the devices when power is supplied through the switch box; And a control unit controlling the operation of the LCR metering unit to inspect the performance before power supply to each of the devices and controlling the switch box and the diagnosis unit to check the performance of each device after power is supplied Which can be achieved by a power device automatic diagnosis system.

And a storage unit for storing the result of the LCR metering unit and the result of the performance check of each of the elements from the diagnosis unit.

Wherein the switch box is connected to a pair of power lines connecting the power device module and each component element in the diagnostic device and a power supply unit for supplying power to the connection device to supply power to the power device module, And a reverse power supply relay mounted in parallel with the direct current power supply relay in a pair of cross lines interconnecting the respective power supply lines to intermittently supply the reverse power to the power device module.

The switch box includes a plurality of branch lines branched from the pair of power supply lines extending from the power supply unit and connected to the plurality of power device modules, And a relay for interrupting the power supply.

The controller may turn on the DC power source relay when the forward power is supplied to one of the plurality of power device modules, turn off the reverse power source relay, and turn on the relay that controls the power device module.

When the reverse power is supplied to one of the plurality of power module modules, the control unit turns the DC power source relay on, turns on the reverse power source relay, and turns on the relay that controls the power device module.

According to the power device automatic diagnosis system according to the present invention, module testing and characteristic analysis of each power device valve constituting the voltage source inverter of the FACT facility can be performed automatically and collectively. Accordingly, it is possible to efficiently perform individual diagnosis and characteristic analysis of each power device of the voltage source inverter for maintenance of the FACTS facility.

In addition, the computer performs all test items, records and displays the results, and stores the test results in a database so that the aging of the devices of each power device module can be tracked. This enables diagnosis and characterization of power device valves as well as individual diagnosis and characterization of each power device, thereby maximizing maintenance efficiency and maximizing accuracy and reliability of voltage source inverter inspection. .

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. It is to be understood that the following terms are defined in consideration of the functions of the present invention, and this may be changed according to the intention of the user, the operator, or the custom, so that the meaning of each term should be interpreted based on the content will be.

FIG. 1 is a schematic configuration diagram of a power device automatic diagnosis system according to the present invention, and FIG. 2 is a block diagram of the power device automatic diagnosis system of FIG.

The power device automatic diagnosis system includes a user terminal 10 operated by a user to control a diagnostic process of a power device module, a diagnostic device 20 performing diagnosis of the power device module, a power device module and a diagnostic device 20 And a connection device (30) for connection. Here, the diagnostic device 20 and the connection device 30 may be manufactured as one device or may be manufactured as a separate device.

In the embodiments described below, the present automatic power diagnosis system is used for diagnosis and test analysis of the power module constituting the voltage source inverter of the FACTS. However, It is of course also possible to use the device module or the circuit diagnosis and test analysis of various structures.

The user terminal 10 includes an input unit 11, a display unit 12, a storage unit 13, a control unit 15, and an interface unit 14.

The input unit 11 is used for controlling the test and diagnosis of the power device module by the user using the diagnostic device 20 and the connection device 30. The display unit 12 displays the operation state of the diagnostic device 20, 20). ≪ / RTI > The storage unit 13 stores the test result of the power device performed by the diagnostic unit 20. [ The interface unit 14 communicably connects the user terminal 10 and the diagnostic device 20 to exchange data with the diagnostic device 20. [ The control unit 15 controls the interface unit 14 to transmit the command inputted through the input unit 11 to the diagnosis unit 20 and displays the diagnosis result provided from the diagnosis unit 20 on the display unit 12, To be stored in the storage unit 13.

The connection device 30 is connected to the diagnostic device 20 and controls the power supply to the power device under the control of the diagnostic device 20 to perform the pre-compression test and the post-compression test, and the plurality of the connection terminals 35, An LCR metering section 31, and a switch box 33.

The plurality of connection terminals 35 are connected to both ends of a power device, a reverse-parallel diode, and a snubber circuit, which are respective elements to be inspected in each power device module constituting the voltage source inverter of the FACTS.

The LCR metering unit 31 measures the impedance, resistance, and capacitance of each passive element and analyzes characteristics of the passive elements before performing the pre-pressurization test before supplying power to each power element module. The pre-press test includes a power device DC conduction test, a DC resistance test for resistance elements, an impedance test for R-C elements, a capacitance test, and a reverse-parallel diode test. The result measured by the LCR metering unit 31 is transmitted to the user terminal 10 via the diagnostic unit 20. [

The switch box 33 is provided with a plurality of switches for controlling the supply of power to each connection terminal 35 and determining the test path for each power element in the post-pressurization test performed by supplying power to each power element module .

The diagnosis unit 20 includes a power supply unit 24, a first interface unit 21, a second interface unit 22, a diagnosis unit 23, and a control unit 25.

The power supply unit 24 supplies power to each component element and the connection device 30 in the diagnostic device 20. [

The first interface unit 21 is connected to the interface unit 14 of the user terminal 10 to enable communication between the user terminal 10 and the diagnostic device 20, (30) so that data can be exchanged.

The diagnosis unit 23 measures the cut-off voltage, the conduction voltage, the conduction current, and the like transmitted from the active elements of each power device module when the post-pressurization test of each power device module is performed through the connection device 30, The active element is determined based on the cut-off voltage, the conduction voltage, and the conduction current measured for the active element. The results of the determination by the diagnosis unit 23 are transmitted to the control unit 25.

The control unit 25 controls the LCR metering unit 31 and the switch box 33 of the connection device 30 in accordance with a command from the user terminal 10 so as to perform the pre-pressurization test and the post- do. The control unit 25 controls ON / OFF of each relay to be described later to selectively supply power to the GTO G1 and the anti-parallel diode D1 when conducting the post-pressurization test, thereby measuring the cutoff voltage, the conduction voltage, . The LCR metering unit 31 transmits information on the result of the passive element analyzed and whether there is an abnormality in the active element determined by the diagnosis unit 23 to the user terminal 10. [

3 is a circuit diagram of a power device module diagnosed by the power device automatic diagnosis system of the present invention.

The power element module includes a plurality of passive elements and active elements. The passive elements include resistors R1, R2, R3 and capacitors C1, C2. The active elements include a GTO (gate turn-off thyristor) G1, A parallel diode D1, and a snubber diode D2.

Here, the performance of the passive elements R1, R2, R3, capacitors C1 and C2 is tested by pre-pressurization test, and the performance of the active elements GTO G1, antiparallel diode D1, snubber diode D2, Test. This is because the functions of semiconductor devices such as GTO G1, antiparallel diode D1, and snubber diode D2 are precisely measured when a voltage is applied and current flows.

For the pre-pressurization test of the passive elements, the connection terminals 35 of the connection device 30 are connected to the power device module, respectively, as shown in Fig.

In FIG. 3, the pre-pressurization test of the passive element can measure C1 and R2 by measuring between point A and point B. At this time, R1, R3 and C2 have relatively large impedance, . Because R3 and C2 are relatively larger in impedance than R2, it is impossible to measure them in parallel with R2. Accordingly, after separating the D point, measure the C2 value between the C point and the E point, and measure the R3 value between the D point and the E point.

For the pre-pressurization test of the active element, as shown in Fig. 4, the connection terminals 35 of the connection device 30 are connected to four places of the power device module, respectively. Then, a voltage of 1000 V and a current of 100 A are applied, respectively, and then the cut-off voltage, the conduction voltage, and the conduction current are measured to judge the presence or absence of abnormality of each element.

First, positive voltage is applied between point A and point B, then current is applied to check GTO G1, negative voltage is applied, and reverse current is applied to check D1. Then, D2 is checked by alternately applying a positive voltage and a negative voltage between point C and point D.

On-drop test of GTO G1 and antiparallel diode D1 is performed by conducting the GTO device or the antiparallel diode and measuring the on-drop voltage and checking whether the value is within the specification range. . In the present invention, it is possible to analyze the aging change by storing not only the abnormality of the GTO G1 and the antiparallel diode D1 but also the diagnosis result in the storage unit 13 of the user terminal 10.

For the on-drop test of the GTO G1 and the antiparallel diode D1, as shown in FIG. 5, an anode and a cathode of a GTO are connected to a DC power source capable of applying a 1000 V direct voltage, and a di / dt inductor is connected to the anode And a 100 Ω resistor is connected to the cathode. At this time, a forward voltage of 1000V is applied to the GTO for the on-drop test of G1, and a reverse voltage of 1000V is applied for the on-drop test of the inverse parallel diode D1. To this end, a DC power supply relay for applying a forward voltage and a reverse power supply relay for applying a reverse voltage are connected in parallel between the DC power supply and each power device module.

Meanwhile, as shown in FIG. 6, one power element valve includes five power element modules, and a relay or a switch is mounted so that five power element modules can be sequentially inspected using one DC power source .

A DC power supply relay for applying a forward voltage is provided in a pair of power supply lines extending from the anode and the cathode of the DC power supply. A pair of reverse lines are formed on the power supply line provided with the DC power relay so as to cross-connect the power supply line connected to the anode and the power supply line connected to the cathode. Each reverse line is equipped with a reverse power relay, and the DC power relay and the reverse power relay are connected in parallel with each other. Here, the DC power supply relay connected to the DC power supply is indicated by S-G, and the reverse power supply relay is indicated by S-D.

On the other hand, the power supply lines are branched by the number of the power device modules to form a plurality of pairs of branch lines connecting the anode and the cathode of the GTO of each power device module to the DC power source. And each relay is mounted on each branch line. In the case where there are five power device modules, if the power device modules are named power device modules 1 to 5, respectively, a pair of relays S1 to S5 are mounted to the power device modules 1 to 5, respectively.

A process of performing the on-drop test of the GTO G1 and the antiparallel diode D1 of the power device modules 1 to 5 in the power device valve according to this configuration will be described with reference to Table 1 below.

First, when the on-drop test of the GTO G1 of the power element module 1 is performed, the controller 25 of the diagnostic device 20 turns on the relay S1 and turns off the relays S2 to S5. And turns on relay S-G to provide forward power to GTO G1, and turns off relay S-D. In this state, the control unit 25 turns on the GTO 1 ms later, and the conduction voltage across the GTO is measured 1 msec by the diagnosis unit 23 to determine whether or not the GTO is abnormal. The control unit 25 transmits information on the measured continuity voltage value and whether or not there is an abnormality to the user terminal 10. The user terminal 10 stores the received measurement value and information on the presence or absence of abnormality in the storage unit 13 and externally displays the information through the display unit 12 according to the user's selection. Then, the measured value is measured, then the GTO is turned off and the relay S-G is turned off.

When the on-drop test of the antiparallel diode D1 of the power device module 1 is performed, the controller 25 of the diagnostic device 20 turns off the relay SG while the relay S1 is turned on, turns on the relay SD, Diode D1 is provided with the power supplied to the GTO G1 and the power supplied in the reverse direction. Then, the diagnosis section 23 measures the conduction voltages at both ends of the diode D1 after 1 msec, and measures the conduction current flowing through the diode D1. The diagnosis unit 23 determines the presence or absence of an abnormality of the diode D1 by using the measured conduction current and conduction voltage, and the controller 25 transmits information on the presence or absence of the conduction voltage value and the conduction current value to the user terminal 10 ). And the relay S-D is turned off.

When on-drop testing of the GTO G1 and antiparallel diode D1 of the power device module 2 is performed, the relay S2 is turned on and the relays S1 and S3 to S5 are turned off. Then, when the on-drop test of the GTO G1 is performed, the relay S-G is turned on. When the on-drop test of the anti-parallel diode D1 is performed, the relay S-D is turned on.

In the on-drop test of the GTO G1 and the antiparallel diode D1 of the power device module 3, the relay S3 is turned on. In the on-drop test of the GTO G1 of the power device module 4 and the antiparallel diode D1, the relay S4 is turned on, In the on-drop test of the GTO G1 of the power device module 5 and the antiparallel diode D1, the relay S5 is turned on. In this state, the relay S-G is turned on when the on-drop test of the GTO G1 is performed, and the relay S-D is turned on when the on-drop test of the anti-parallel diode D1 is performed.

Exam contents Relay on / off S1 S2 S3 S4 S5 S-G S-D On-drop test of GTO G1 of power device module 1 On off off off off On off D1 on-drop test of power device module 1 On off off off off off On On-drop test of GTO G1 of power device module 2 off On off off off On off D1 on-drop test of power device module 2 off On off off off off On On-drop test of GTO G1 of power device module 3 off off On off off On off D1 on-drop test of power device module 3 off off On off off off On On-drop test of GTO G1 of power device module 4 off off off On off On off D1 on-drop test of power device module 4 off off off On off off On On-drop test of GTO G1 of power device module 5 off off off off On On off D1 on-drop test of power device module 5 off off off off On off On

As described above, when the present power device automatic diagnosis system is used, each connection terminal 35 is connected to the measurement position of the power device module for pre-pressurization and post-pressurization tests of the passive device and the active device in the power device module. Then, in the pre-pressing test, the connection terminals 35 connected to both ends of the respective passive elements are turned on so that the values of the passive elements, for example, the resistance value or the capacitance, can be detected. In the post-pressurization test, the DC power supply is connected to the DC power supply and the reverse power supply relay is provided to provide the DC power in the reverse direction and the reverse power supply relay is provided in the reverse direction. Thus, An on-drop test can be performed by supplying power. In addition, a plurality of power device modules can be automatically tested and diagnosed by providing a relay for interrupting a branch line branched from a DC power supply and a DC power supplied to each power device module.

The diagnostic result is transmitted to the user terminal 10 via the diagnostic unit 20. The user terminal 10 stores the diagnostic history and constructs the database so that the passive elements and the active elements of the power element module Interannual variability can be analyzed.

1 is a schematic block diagram of a power device automatic diagnosis system according to the present invention;

Fig. 2 is a block diagram of the power device automatic diagnosis system of Fig. 1,

FIG. 3 is a circuit diagram of a power device module in which a connection terminal position is shown in a pre-pressurization test using the power device automatic diagnosis system of FIG. 1;

4 is a circuit diagram of a power device module in which a connection terminal position is shown in a test after pressurization using the power device automatic diagnosis system of FIG.

FIG. 5 is a power supply circuit diagram for testing one power device module using the power device automatic diagnosis system of FIG. 1;

6 is a power supply circuit diagram for testing a plurality of power device modules using the power device automatic diagnosis system of FIG.

Description of the Related Art

10: user terminal 11: input unit

12: display section 13: storage section

14: interface unit 15: control unit

20: diagnosis unit 21: first interface unit

22: second interface section 23: diagnosis section

24: power supply unit 25:

30: connection device 31: LCR metering section

33: Switch box 35: Connection terminal

Claims (6)

An LCR metering unit for checking performance before power is supplied to each device constituting each power device module used in the power system; A plurality of connection terminals connected to both ends of each of the elements; A switch box having a plurality of switches for interrupting a power supply provided to each element through the connection terminal to check performance after power supply to each of the elements; A diagnostic unit for analyzing performance of each of the devices according to voltage and current values measured from the devices when power is supplied through the switch box; And And a control unit controlling the operation of the LCR metering unit to inspect the performance of each device before power supply and controlling the switch box and the diagnosis unit to check the performance of each device after power is supplied Power device automatic diagnosis system. The method according to claim 1, Further comprising a storage unit for storing the result of the performance check of the LCR metering unit and the respective elements from the diagnosis unit. The method according to claim 1, The switch box includes: A DC power supply relay mounted on a pair of power supply lines for connecting the power device module and each component element in the diagnostic device to a power supply unit for supplying power to the connection device to intermittently supply the forward power to the power device module; And a reverse power supply relay mounted in parallel with the direct current power supply relay in a pair of cross lines interconnecting the power supply lines to intermittently supply the reverse power to the power device module. . The method of claim 3, The switch box includes: A plurality of branch lines branched from the pair of power supply lines extended from the power supply unit and connected to the plurality of power device modules, respectively, and a power source provided to each of the power device modules and interrupted And a relay. 5. The method of claim 4, Wherein, Wherein the DC power supply relay turns on when the DC power is supplied to one of the plurality of power device modules, turns off the reverse power relay, and turns on the relay that controls the power device module. Diagnostic system. 5. The method of claim 4, Wherein, Wherein the controller turns on the relay for turning on the DC power source relay, turns on the reverse power relay, and turns on the relay for controlling the power device module when the reverse power is supplied to one of the plurality of power device modules. Diagnostic system.

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