KR0152889B1 - Simple function inspection method for digital protection relay - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simple performance test method for a digital protective relay. The present invention relates to a first process for inputting various information such as signal size, frequency and period, number of sampling and input contact number of a digital protective relay, etc. and; A second process of generating test data in the microprocessor according to the various information of the first process; A third step of storing the test data of the second process in a memory and converting the stored test data into a test signal and transmitting the stored test data to a digital protection relay if there is a transmission command for the test data; After the transmission in the third step, the fourth step of determining the normal operation by checking the operation state of the input contact of the digital protection relay, and properly checks the performance of the digital protection relay even if the measurement target of the digital protection relay changes. It is possible to generate transformer excitation inrush current, three-phase current and voltage as test signals, making the inspection process very convenient in three-phase testing.

Description

Simplified performance test method of digital protective relay.

1 is a block diagram of an apparatus used for carrying out a simple performance test method of a conventional digital protective relay.

2 is a block diagram of an apparatus used for carrying out the simple performance test method of the digital protective relay of the present invention.

3 is a flow chart of operation in FIG.

* Explanation of symbols for main parts of the drawings

10: key input unit 20: display unit

200: personal computer 201: microprocessor

202 RAM 203 Digital / Analog Converter

204: low pass filter 205: amplifier

206: control logic unit 207: flip-flop

The present invention relates to a simple performance test method of a digital protective relay for checking whether the digital protective relay is operating normally, in particular, the magnitude, frequency and period of the signal input from the digital relay by changing the measurement target of the digital protective relay and the digital / analog The present invention relates to a simple performance test method of a digital protection relay that can properly check whether the digital protection relay operates normally even if the number of sampling for the input of the converter and the number of input contacts of the digital protection relay vary.

In general, when the measurement target is changed in the digital protective relay, there are variations in the signal size, frequency and period, the number of sampling for the input of the digital / analog converter, and the number of input contacts of the digital protective relay. In order to properly check the digital protection relay for normal operation, it is necessary to generate a test signal that can adapt to the above fluctuations.

1 is a block diagram of a performance testing apparatus for a digital protection relay used in the practice of a simple performance testing method of a conventional digital protection relay.

The method for checking whether the digital protective relay operates normally by using the performance tester of the digital protective relay includes the magnitude, frequency, and period of the signal, and the number of sampling for the input of the digital / analog converter 103 and the digital protective relay. Regardless of the variation in the number of input contacts, the first process of generating constant test data according to the internal function of the microprocessor 201 and the test data generated in the first process are stored in the RAM 102. If there is a second process to store and a transmission command for test data from the outside through the key input unit 10, the test data stored in the RAM 102 in the second process is converted into a predetermined test signal and the digital protection relay A third process of transmitting to the second circuit; and an operation state of an input contact of the digital protection relay after the transmission in the third process, A fourth process for determining the operation status and, comprises a fifth step of displaying the determination result in the fourth step on the display (display) unit 20.

The operation will be described below.

The microprocessor 101 has a predetermined internal function, and according to the internal function, the microprocessor 101 performs signal magnitude, frequency, and period, and the number and sampling numbers for the input of the digital / analog converter 103. The test data is generated regardless of the variation of the number of input contacts of the protection relay, and is transmitted to the RAM 102 through the data bus B1 and stored therein.

After the test data is stored in the RAM 102 as described above, when a transfer command for notifying the transfer of the test data from the external key input unit 10 is input to the microprocessor 101, the microprocessor 101 previously stores the RAM ( The test data stored in 102 is read out and input to the digital / analog converter 103.

The digital / analog converter 103 converts the received test data into an analog signal and inputs it to the low pass filter 104. The low pass filter 104 removes the harmonic signal included in the analog signal to test it. A signal is generated and input to the amplifier 105. The amplifier 105 amplifies the input test signal appropriately, outputs it through the output terminal OUT, and transmits the signal to the digital protection relay under test.

In the digital protection relay receiving the test signal, the input contact is operated, and the microprocessor 101 checks the operation state of the input contact to determine whether the digital protection relay is in normal operation, and then displays the determination result. 20).

Such a simple performance test method of the conventional digital protective relay is to change the measurement target of the digital protective relay to change the signal size, frequency and period, the number of sampling for the input of the digital / analog converter and the number of input contacts of the digital protective relay If there is a change, it cannot adapt to the performance of the digital protective relay, and it is suitable for the single-phase test that generates and checks the test data. There was a problem with the hassle.

In view of such a conventional problem, the present invention changes the measurement target of a digital protective relay to change the signal size, frequency and period, the number of sampling for input of the digital / analog converter, the number of input contacts of the digital protective relay, and the like. It is an object of the present invention to provide a simple performance test method of a digital protective relay that can properly inspect the performance of the digital protective relay even if there is a change.

It is another object of the present invention to provide a simple performance test method of a digital protective relay suitable for performance testing of a relay requiring a six-phase (voltage three-phase, current three-phase) test, such as a ground fault selective relay. In the simplified performance test method of the digital protective relay of the present invention according to the above objects, referring to FIG. 2 showing the performance test apparatus of the digital protective relay used in the practice of the present invention, a signal is generated using the personal computer 200. A first step of inputting various types of information such as the size, the frequency and the period, and the number of sampling and the number of input contacts of the digital protection relay to the microprocessor 201; A second process of generating test data in the microprocessor 201 according to the various information of the first process; After storing the test data of the second process in the RAM 202 which is a memory and converting the stored test data into a test signal when there is a transmission command for the test data from the external key input unit 10, the digital signal is protected. Transmitting to a relay; After the transmission in the third process, a fourth process of determining whether or not normal operation is performed by checking the operation state of the input contact of the digital protection relay.

Hereinafter, the operation will be described in detail.

See FIG. 3.

First, the external personal computer 200 generates and edits various kinds of information such as signal size, frequency and period, sampling number for input of the digital / analog converter 203 and the number of input contacts of the digital protection relay. (ST1), the serial transmission is carried out via a serial communication interrupt (SCI; Serial Communication Interrupt) and input to the microprocessor 201 of the simplified performance inspection apparatus of the digital protective relay (ST2).

Accordingly, the microprocessor 201 generates test data from the above various information, and the RAM enable signal ( ) Is input to the RAM 202 and the light signal ( ) Is stored and transmitted to the RAM 202 via the data bus B1.

After the test data is stored in the RAM 202 as described above, when a transfer command for notifying the transfer of the test data from the external key input unit 10 is input to the microprocessor 201, the microprocessor 201 reads a read signal. ( ), The test data stored in the RAM 202 is read and input to the digital / analog converter 203 (ST3).

On the other hand, the microprocessor 201 is a RAM enable signal (through the control logic unit 206) Converter enable signal with signal state opposite to ) Is inputted to the digital / analog converter 203, and the address signals A1 and A2 are outputted and input together. Accordingly, the digital / analog converter 203 is previously used by the microprocessor 201. The input test data is converted into an analog signal and input to the low pass filter 204.

At this time, the RAM enable signal ( ) And the converter enable signal ( (Or flip-flop 207) have opposite states, so the access timing of the RAM 202 and the access timing of the digital / analog converter 203 are reversed.

Meanwhile, the low pass filter 204 generates a test signal by removing a harmonic signal having a predetermined order (for example, '10') or more in the analog signal input from the digital / analog converter 203 and generating an test signal. Reference numeral 205 amplifies the test signal, outputs it through the output terminal OUT, and transmits the signal to the digital protective relay side under test (ST4).

After the transmission of the test signal is completed, the microprocessor 201 is in a standby state for measuring the digital relay operation time (ST5) (ST6).

On the other hand, in the digital protection relay receiving the test signal, an input contact is operated, and the microprocessor 101 checks the operation state of the input contact to determine whether the digital protection relay is normally operated, and then displays the determination result. (20) (ST7) (ST8).

On the other hand, the present invention inputs the information for generating the transformer inrush current (inrush current) or three-phase current, voltage in the personal computer 200 to the microprocessor 201, by using the microprocessor 201 predetermined By generating the test data for the test, it is possible to check whether the transformer protection relay or the ground circuit selection relay is in normal operation.

In particular, when inspecting the ground line selection relay, the digital / analog converter 203 latches the test data of the six phases in the internal register when the microprocessor 201 inputs the test data of the six phases. Is converted into an analog signal to control signals from the microprocessor 201. ) Is inputted at the same time and inputted to the low pass filter 204. At this time, of course, the number of output channels of the digital / analog converter 203 is plural, and the selection thereof is made by the addresses A1 and A2 output from the microprocessor 201.

As described in detail above, the present invention generates a test signal according to the size, frequency and period of the signal, the number of sampling for input of the digital / analog converter and the number of input contacts of the digital protection relay. Even if the measurement object is changed, the performance of the digital protection relay can be properly inspected, and the inrush current and the three-phase current and voltage can be generated at the same time as the test signal, so the inspection process is very convenient in the three-phase test.

Claims (2)

A first step of inputting a variety of information, such as the size, frequency and period of the signal, the number of sampling and the number of input contacts of the digital protection relay to the microprocessor; for testing in the microprocessor according to the information of the first process A second process of generating data; and storing the test data of the second process in a memory and converting the stored test data into a test signal if the transfer command for the test data is received from the outside to the digital protection relay. And a fourth process of determining whether the digital protection relay is normally operated by checking an operation state of an input contact of the digital protection relay after the transmission in the third process. Simple performance test method of relay. The method of claim 1, wherein the first process inputs information on transformer excitation inrush current or three-phase current and voltage generation to the microprocessor to inspect whether the transformer protection relay or the ground circuit selection relay is normally operated. Simple performance test method of digital protective relay.