CN110609190A - A relay protection device outlet calibration instrument and method thereof - Google Patents

Abstract

The invention relates to the technical field of power systems, in particular to an outlet calibration instrument and method for a relay protection device in a power system relay protection device regular calibration outlet calibration link. The LED intelligent alarm device comprises a shell, and a power supply circuit, an outlet voltage acquisition circuit, a signal transmission isolation circuit, a central processing unit, an LED driving display circuit, a liquid crystal display circuit, a buzzer alarm circuit and a key input circuit which are arranged in the shell; the LED alarm device is characterized in that the outlet voltage acquisition circuit, the signal transmission isolation circuit and the central processing unit are sequentially connected, the central processing unit is further respectively connected with the LED driving display circuit, the liquid crystal display circuit, the buzzer alarm circuit, the key input circuit and the power circuit, and the power circuit is further respectively connected with the LED driving display circuit, the liquid crystal display circuit and the buzzer alarm circuit. The method comprises the step that the outlet voltage acquisition circuit divides the voltage of the high resistance in the circuit. The invention reduces auxiliary instruments, simplifies the test process and improves the test accuracy.

Description

A relay protection device outlet calibration instrument and method thereof

technical field

The invention relates to the technical field of power systems, in particular to a relay protection device outlet calibration instrument and a method thereof for the regular inspection outlet verification link of a power system relay protection device.

Background technique

With the rapid development of the power system today, relay protection devices play an important role in ensuring the reliable operation of the power grid. According to the "China Electric Power Industry Standard DL/T 995-2006 Inspection Regulations for Relay Protection Devices": "When conducting all inspections of relay protection devices, the on-off status of the output contacts (outlets) that are put into use must be checked in sequence. "

At present, due to various reasons such as various types of substation protection devices, heavy regular inspection workload, staff misuse, device failure and other reasons, the outlet verification of substation protection devices has "false detection" and "missing detection", resulting in "sick operation" of protection devices. ", "misoperation", "action not exported" and other accidents occur from time to time.

The protective device outlet calibrator is mainly used in the transmission process of the protective device to detect the potential and time of the lower end of the outlet pressure plate in the protective outlet link, and independently judge whether it is consistent with the setting of the protective device. When the order and time of protection exits are different from the setting of protection settings, it will cause wrong exits and cause large-scale power outages.

Existing relay protection testers (such as Onli, Relay Protection Star D7000, Bodian) can only complete the verification of the internal action logic of the protection device by adding time-limited current and voltage to the device, and none of them involve To the calibration of the protection outlet pressure plate, the potential of the lower end of the outlet pressure plate during the transmission process is usually measured with the help of a multimeter, and the successive actions of each outlet are determined by visually observing the successive changes of the indications.

Using a manual multimeter requires at least two people to complete the test, which is redundant and inefficient. For a protection device with a single outlet, it is easy to realize the calibration by observing the multi-meter indication; for a protection device with multiple outlets, multiple multimeters are required to measure the potential at the lower end of the outlet pressure plate at the same time. First, multiple multimeters measure the corresponding outlet pressure plate at the same time, which is easy There is a phenomenon of poor contact. Secondly, multiple multimeters must be of the same model. Different types of meters have different inherent delays in the acquisition process, and there are errors that will affect the final judgment result. Due to the fast action of the internal nodes of the protection device, the check of the potential of the outlet pressure plate needs to be completed in a very short time, and the observation level of the human eye is limited. Observing the potential of multiple protection outlet pressure plates at the same time is prone to inaccurate observation results and miscalibration test phenomenon. Usually the calibration process requires multiple measurements, and finally the test results are summarized to obtain the maximum distribution.

Therefore, the existing test method of the outlet verification link of the protection device is purely manual operation, which is prone to poor connection between the instrument and the outlet pressure plate, resulting in inaccurate test results; the test process has high requirements for the observation level of the instrument and human eyes. Larger; at the same time, the test process requires multiple measurements, which has disadvantages such as low efficiency.

Contents of the invention

In view of the above-mentioned prior art, the object of the present invention is to provide a relay protection device outlet calibration instrument, which can accurately judge and calculate the potential and time of the lower end of the outlet platen during the transmission process of the protection device, and can perform detection and calculation Results are displayed in real time.

In order to achieve the above object, the present invention has taken the following technical solutions:

An export calibration instrument for a relay protection device, comprising a casing and a power supply circuit arranged in the casing, an exit voltage acquisition circuit, a signal transmission isolation circuit, a central processing unit, an LED drive display circuit, a liquid crystal display circuit, and a buzzer alarm circuit and button input circuit; the outlet voltage acquisition circuit, signal transmission isolation circuit and central processing unit are sequentially connected, and the central processing unit is also respectively connected to an LED drive display circuit, a liquid crystal display circuit, and a buzzer alarm circuit , key input circuit and power supply circuit, described power supply circuit is also respectively connected with LED drive display circuit, liquid crystal display circuit, buzzer alarm circuit;

The operating panel of the device shell is provided with a power switch, a grounding terminal plug, an AC input plug, a test button, a liquid crystal display, LED lights and several detection input terminals for connecting the lower end of the outlet pressure plate.

Further, the central processing unit includes a microprocessor and a filter circuit, which are used to complete the logic algorithm processing of the collected signals and control the LED drive display circuit, liquid crystal display circuit, and buzzer alarm circuit; the microprocessor Includes timer.

Further, the power supply circuit includes a power switch, an AC output interface and an AC/DC module for converting and adapting the required power for the instrument.

Further, the outlet voltage acquisition circuit includes a voltage dividing resistor that uses a large resistor to divide the voltage at the front end of the acquisition to reduce the impact on the signal source, and an operational amplifier that connects the signal source that is divided by the large resistor to the microprocessor.

Further, the key input circuit includes four keys using the "common cathode" connection, which are respectively the "confirmation" key to open or close any detection channel, the "up" key and the "down" key to switch the detection channel back and forth. "Flip" key, and "Reset" key for clearing the test results.

Further, the signal transmission isolation circuit is an optocoupler isolation circuit, including a current limiting resistor and an optocoupler isolation circuit.

Further, the power module also includes a spare storage lithium battery.

Further, the microprocessor is an STM32F103 single-chip microcomputer; the LED lamp adopts a high-power, waterproof lamp bead; the liquid crystal display in the liquid crystal display circuit adopts a color liquid crystal screen based on the USART protocol; the detection input terminal adopts a test lead clip.

Beneficial effect:

(1) Use calibration instrument of the present invention and need not rely on human eye and multimeter to observe completely, when carrying out multi-outlet calibration, greatly reduced auxiliary equipment, simplified testing process; When the test results are caused by errors, the detection is inaccurate.

(2) The inspection instrument of the present invention adopts an outlet voltage acquisition circuit, which can simultaneously collect multiple outlet voltages, carry out the isolation of the transmission process through the optocoupler, transmit to the microprocessor for identification and judgment, and minimize the interference factors, and save The human observation and judgment link in the middle is eliminated to improve the accuracy of the testing process.

(3) At least two people are required to carry out the export verification in the traditional way; one of them is responsible for the output of the relay tester, and the other is connected to the multimeter pen, and observes the change of the multimeter. The inspection instrument of the present invention adopts an integrated design, and the outlet calibrator independently completes the potential detection of each outlet pressure plate, and realizes the judgment of the action sequence of each pressure plate through the program inside the microprocessor, and performs real-time display through the liquid crystal display and LED lights .

(4) The inspection instrument of the present invention calculates the time from the transmission start to the output stage of the pressing plate by means of the timer inside the microprocessor, so as to achieve the purpose of checking with the set value setting of the device, and further improve the reliability of the device operation.

(5) The outlet voltage acquisition circuit adopted by the inspection instrument of the present invention will not induce a "DC loop closure" fault when the outlet verification of the protection devices powered by two sets of DC power supplies is carried out at the same time, and the verification process will not affect the DC voltage of the substation. The system is functioning normally.

Aiming at the prior art, the present invention also provides a calibration method based on the above-mentioned outlet calibration instrument of the relay protection device.

In order to achieve the above object, the present invention takes the following technical solutions:

A calibration method based on the above-mentioned outlet calibration instrument of the relay protection device, comprising the following steps:

(1) The outlet voltage acquisition circuit divides the high resistance in the circuit to reduce the influence of the acquisition circuit on the signal source and ensure the integrity of the signal to the greatest extent;

(2) Use optocoupler isolation to transmit to the microprocessor for calculation and judgment: the microprocessor performs coefficient calculation on the collected analog signal through its own analog acquisition channel, and finally obtains the voltage at the lower end of the pressure plate during the action process and performs Judging whether the verified outlet voltage is within the normal setting range; if it is not within the normal setting range, the microprocessor sends out a signal to drive the buzzer control circuit to give an alarm;

(3) The microprocessor then uses the internal timer to count, and performs logic operations and sorting on a number of detection channel values received from the optocoupler isolation circuit, so as to obtain the action time and sequence of action of the above-mentioned several pressing plates;

(4) Drive the LED light to realize the synchronous lighting of the logic operation result and the corresponding LED lamp beads; at the same time, control the LCD screen to display the current acquisition channel situation, including: action time, action sequence, and real-time voltage;

(5) "Reset" the above inspection results, clear the results of the current round of verification, and prepare for the next round of seconds verification.

Further, in step (1), when the signal input impedance is greater than 10 megaohms, perform high-impedance voltage division.

Further, the microprocessor is a STM32F103 single-chip microcomputer, which has the following functions: analog quantity sampling, internal calculation, data storage, reading clock, logic judgment, signal output, liquid crystal, LED display drive, fault judgment output.

Furthermore, the LED drive display circuit is used to synchronously display whether the outlet pressure plate is moving in real time. It is driven by a Darlington power tube and connected by "common cathode"; Next round of testing.

Further, the connection between the microprocessor and the buzzer is realized through a triode.

Beneficial effect:

(1) The use of high-impedance operational amplifiers and the application of optocoupler isolation in the transmission process ensure the integrity of the signal to the greatest extent and ensure the accuracy of signal acquisition from the source;

(2) With the help of the timer inside the microprocessor, the full-scale accurate recording of the potential change of the lower end of the pressure plate during the transmission process is realized, and the accurate judgment of the action sequence of the protection pressure plate is realized, which avoids the hidden danger of human error calibration and misjudgment, and improves the protection device. operational reliability;

(3) One-button operation, automatic inspection, greatly reducing manpower input, reducing intermediate links, and greatly shortening the time spent in the export verification process, thereby shortening the time for the entire protection and inspection;

(4) With the help of the high-speed and precise processing of the microprocessor, the sequence of each exit action can be accurately judged.

Description of drawings

Figure 1 is a plan view of the calibration instrument at the outlet of the protective device;

Fig. 2 is a system block diagram of the outlet calibration instrument of the protection device;

Fig. 3 is a schematic diagram of the internal circuit of the microprocessor;

Fig. 4 is a schematic diagram of the outlet voltage acquisition circuit;

Fig. 5 is a schematic diagram of the button circuit;

6 is a schematic diagram of a signal transmission isolation circuit;

FIG. 7 is a schematic diagram of an LED drive display circuit;

Fig. 8 is a schematic diagram of the buzzer alarm circuit;

Fig. 9 is a schematic diagram of a power supply circuit;

Figure 10 is a schematic diagram of liquid crystal display circuit wiring;

Figure 11 is a schematic diagram of the main flow of the software;

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

Embodiment one

Figures 1 to 11 show a kind of relay protection device export calibration instrument, including the shell and some circuits inside the shell, the shell is made of magnesium aluminum alloy, as shown in Figure 1, in the figure: 16 LED lights 1. The magnesium-aluminum alloy shell of the calibration instrument 2, the liquid crystal display screen 3, 4 metal waterproof buttons 4, the detection input terminal at the lower end of the 1-16 way exit pressure plate 5, the DC negative terminal 6, the power switch 7, and the grounding terminal socket 8. AC input socket 9.

As shown in Figure 2, the circuits in the magnesium-aluminum alloy casing 22 of the calibration instrument include a power supply circuit, an outlet voltage acquisition circuit, a signal transmission isolation circuit, a central processing unit, an LED drive display circuit, a liquid crystal display circuit, and a buzzer alarm circuit and button 4 input circuit; the outlet voltage acquisition circuit, the signal transmission isolation circuit and the central processing unit are sequentially connected, and the central processing unit is also respectively connected to the LED drive display circuit, the liquid crystal display circuit, and the buzzer alarm circuit, button 4 input circuit and power supply circuit, and the power supply circuit is also connected with LED drive display circuit, liquid crystal display circuit and buzzer alarm circuit respectively.

The central processing unit includes a microprocessor STM32F103 and a filter circuit to complete the logic algorithm processing of the collected signals and control the LED drive display circuit, liquid crystal display circuit, and buzzer alarm circuit. The internal circuit of the microprocessor is shown in FIG. 3 .

As shown in FIG. 9, the power supply circuit includes a power switch 7, an AC output interface and an AC/DC module for converting and adapting the required power for the instrument. When the power switch 7 is turned on, the AC 220V input device is converted into 12V by the AC/DC module to supply power for the instrument, the 12V DC is regulated into +3.3V DC for the microprocessor, and the 12V DC is regulated into +3.3V through the voltage regulator chip. +5V DC is used for the LCD screen.

As shown in Figure 4, the outlet voltage acquisition circuit includes a voltage divider resistor and an operational amplifier to complete 16 analog quantity sampling circuits. The impact on the signal source is minimized, and the integrity of the signal is guaranteed to the greatest extent. Since the GND of the ±110V signal source of the power equipment is generally grounded with high resistance, the use of a large resistance to divide the voltage can ensure that the most real voltage signal is sampled. And when the outlet verification of the protection devices powered by two sets of DC systems are carried out at the same time, the "DC loop closure" alarm will not be induced, and the operation of the DC system in the station will not be affected.

The impedance of the signal source after voltage division by a large resistor is too high, so it cannot directly enter the analog sampling port of the microprocessor, which will cause the impedance of the signal source to not match the impedance of the analog port of the microprocessor, and the voltage value sampled by the microprocessor is Abnormal ones will affect the accuracy of the final export verification. This instrument uses the TLC2274 operational amplifier to do a first-level impedance matching, transforming the high-impedance signal into a low-impedance signal and then entering the analog sampling port of the microprocessor, which ensures the integrity of the sampling signal transmission to the greatest extent and ensures the sampling of the microprocessor. to the voltage accuracy.

The use of TLC2274 not only plays the role of impedance matching in the signal transmission process, but also plays the role of signal isolation, so that there is an additional level of protection between the external interface and the pins of the single-chip microcomputer, which can avoid static electricity or instantaneous high voltage introduced into the circuit board by the external port. Cause damage to the pins of the microcontroller.

As shown in Figure 5, the button 4 input circuit includes four buttons 4 using the "common cathode" connection method, which are respectively the "confirmation" button for opening or closing any detection channel, and the "turn up" button for switching the detection channel back and forth. " key and "scroll down" key, and the "reset" key for clearing the test results. Press the "Reset" button to clear the test result and enter the 30-second test process.

As shown in Figure 6, the signal transmission isolation circuit includes a current-limiting resistor and an optocoupler. For the voltage acquisition circuit, the small voltage signal after internal resistance division cannot be directly sent to the logic operation unit, and electromagnetic interference and signal fluctuations Both will affect the operation and judgment of the logic operation unit on the small voltage signal. Using the optocoupler isolation circuit, the external output voltage signal drives the light-emitting diode, and the internal detection of light is transmitted to the microprocessor after amplification to realize the isolation of the external signal from the voltage acquisition signal. interference.

As shown in Figure 7, the LED drive display circuit includes: a Darlington power amplifier, which is connected to an external 12V direct current for power amplification, and a digital signal is output by a microprocessor to drive an LED lamp with a high-power current at the output end. 1 bead.

As shown in FIG. 8, the buzzer alarm circuit includes: a triode drive circuit, a buzzer, and a microprocessor input circuit. When the microprocessor detects that the outlet voltage is less than 80V or greater than 140V, it will send a signal to drive the buzzer to inform the operator that the DC voltage is abnormal, please check it in time.

The liquid crystal display circuit is used to display the test results in real time. The display content includes the voltage of each acquisition channel, the action time, and the action sequence of each outlet during the transmission process. With the button 4 input circuit, each acquisition channel can be closed or closed. open. The liquid crystal display screen 3 is directly connected with the output control of the microprocessor, as shown in FIG. 10 .

The shell 2 is made of magnesium-aluminum alloy; the LED lamp 1 is a high-power, waterproof lamp bead; the liquid crystal display 3 is a color liquid crystal screen based on the USART protocol; the detection input terminal 5 is a test wire clip; The power module also includes a 12V lithium battery. When the outlet inspection is carried out at the outdoor protection device control cabinet, when the AC 220v is inconvenient, the built-in lithium battery can be used for short-term export verification.

The main software flow of the software program module is:

1. The system initializes for self-test, lights up 16 LED lights 1, displays the initial screen after power-on, delays for about 3 seconds, turns off 16 LED lights 1, and displays the main screen.

2. Enter the main loop, switch-case statement branch detection: (1) whether the up button 4 is pressed, (2) whether the down button 4 is pressed, (3) whether the confirmation button 4 is pressed, (4) the reset button 4 Whether it is pressed, (5) whether the AD sampling flag arrives (once in 1ms), (6) whether the round of verification end flag arrives (arrives 30 seconds after the reset is pressed), as shown in Figure 11.

In summary, the beneficial effects of this embodiment are:

(1) Use calibration instrument of the present invention and need not rely on human eye and multimeter to observe completely, when carrying out multi-outlet calibration, greatly reduced auxiliary equipment, simplified testing process; When the test results are caused by errors, the detection is inaccurate.

(2) The inspection instrument of the present invention adopts an outlet voltage acquisition circuit, which can simultaneously collect multiple outlet voltages, carry out the isolation of the transmission process through the optocoupler, transmit to the microprocessor for identification and judgment, and minimize the interference factors, and save The human observation and judgment link in the middle is eliminated to improve the accuracy of the testing process.

(3) At least two people are required to carry out the export verification in the traditional way; one of them is responsible for the output of the relay tester, and the other is connected to the multimeter pen, and observes the change of the multimeter. The inspection instrument of the present invention adopts an integrated design, and the outlet calibrator independently completes the potential detection of each outlet pressure plate, and realizes the judgment of the action sequence of each pressure plate through the program inside the microprocessor, and performs real-time monitoring through the liquid crystal display 3 and the LED light 1. display.

(4) The inspection instrument of the present invention calculates the time from the transmission start to the output stage of the pressing plate by means of the timer inside the microprocessor, so as to achieve the purpose of checking with the set value setting of the device, and further improve the reliability of the device operation.

(5) The outlet voltage acquisition circuit adopted by the inspection instrument of the present invention will not induce a "DC loop closure" fault when the outlet verification of the protection devices powered by two sets of DC power supplies is carried out at the same time, and the verification process will not affect the DC voltage of the substation. The system is functioning normally.

(6) The shell 2 of the panel of the device is made of an aluminum-magnesium alloy shell 2, which has a strong ability to resist electromagnetic interference and improves the stability of the device.

Embodiment two

A calibration method based on the above-mentioned outlet calibration instrument of the relay protection device, comprising the following steps:

(1) The outlet voltage acquisition circuit divides the high resistance in the circuit to reduce the influence of the acquisition circuit on the signal source and ensure the integrity of the signal to the greatest extent;

(2) Use optocoupler isolation to transmit to the microprocessor for calculation and judgment: the microprocessor performs coefficient calculation on the collected analog signal through its own analog acquisition channel, and finally obtains the voltage at the lower end of the pressure plate during the action process and performs Judging whether the verified outlet voltage is within the normal setting range, if not within the normal setting range, the microprocessor will send a signal to drive the buzzer control circuit to give an alarm;

(3) The microprocessor then uses the internal timer to count, and performs logic operations and sorting on a number of detection channel values received from the optocoupler isolation circuit, so as to obtain the action time and sequence of action of the above-mentioned several pressing plates;

(4) Drive the LED lamp 1 to realize the synchronous lighting of the logic operation result and the corresponding LED lamp 1 beads; at the same time, control the LCD screen to display the current acquisition channel situation, including: action time, action sequence, and real-time voltage;

(5) "Reset" the above inspection results, clear the results of the current round of verification, and prepare for the next round of seconds verification.

In step (1), when the signal input impedance is greater than 10 megaohms, perform high-impedance voltage division.

The microprocessor is STM32F103 single-chip microcomputer, which has the following functions: analog quantity sampling, internal calculation, data storage, reading clock, logic judgment, signal output, liquid crystal, LED display drive, fault judgment output.

The LED drive display circuit is used to synchronously display whether the outlet pressure plate is moving in real time. It is driven by a Darlington power tube and connected with a "common cathode"; after the detection is started, the LED light 1 will be self-locking and keep on, and it will go out after reset and wait for the next step. round of testing.

The connection between the microprocessor and the buzzer is realized through a triode.

In summary, the beneficial effects of this embodiment are:

(1) The use of high-impedance operational amplifiers and the application of optocoupler isolation in the transmission process ensure the integrity of the signal to the greatest extent and ensure the accuracy of signal acquisition from the source;

(2) With the help of the timer inside the microprocessor, the full-scale accurate recording of the potential change of the lower end of the pressure plate during the transmission process is realized, and the accurate judgment of the action sequence of the protection pressure plate is realized, which avoids the hidden danger of human error calibration and misjudgment, and improves the protection device. operational reliability;

(3) The integrated design and one-button operation greatly reduce the manpower input, reduce the intermediate links, and greatly shorten the time for the export verification process, so that the time for the entire protection and inspection is shortened. According to statistics, the instrument has completed The average time for all the export verification links of a group of 220kV transformer protection devices is 1.9 hours. Compared with the traditional method, the average saving time is 1.7 hours.

(4) The logical judgment adopts the industry's first "protection exit node action judgment algorithm". Through software simulation, machine simulation, and with the help of the high processing speed of the microprocessor, the exit node action judgment algorithm is creatively developed to accurately judge each The sequence of export actions fills the gap in the industry and provides valuable experience for subsequent continuous development and application, which has a strong reference value.

In short, the "integrated design" of the outlet calibrator of the protection device of the present invention can greatly reduce the participation of maintenance personnel, and the "one-key operation" shortens the redundant links in the middle and reduces interference factors; it is realized through the assistance of the microprocessor High-precision collection and high-efficiency calculation and judgment are achieved, redundant test operations are saved, the test time is greatly shortened, and the accuracy of the detection process is improved; an alarm circuit is added to test the change of DC system voltage in the detection station during the whole process; the outlet potential Check with the time to improve the reliability of the protection device operation.

The above are only preferred specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto, any person familiar with the technical field within the technical scope disclosed in the present invention, according to the technical scheme of the present invention and Any equivalent replacement or modification of the inventive concept falls within the protection scope of the present invention.

Claims (10)

1. An outlet calibration instrument of a relay protection device is characterized by comprising a shell, and a power supply circuit, an outlet voltage acquisition circuit, a signal transmission isolation circuit, a central processing unit, an LED driving display circuit, a liquid crystal display circuit, a buzzer alarm circuit and a key input circuit which are arranged in the shell; the output voltage acquisition circuit, the signal transmission isolation circuit and the central processing unit are sequentially connected, the central processing unit is also respectively connected with the LED driving display circuit, the liquid crystal display circuit, the buzzer alarm circuit, the key input circuit and the power circuit, and the power circuit is also respectively connected with the LED driving display circuit, the liquid crystal display circuit and the buzzer alarm circuit; the device shell is provided with a power switch, a grounding terminal plug, an alternating current input plug, a test button, a liquid crystal display screen, an LED lamp and a plurality of paths of detection input terminals for connecting the lower end of the outlet pressing plate.

2. The calibration instrument of claim 1, wherein said central processing unit includes a microprocessor and a filter circuit for performing logic algorithm processing of the collected signals and controlling of the LED driving display circuit, the liquid crystal display circuit, the buzzer alarm circuit; the microprocessor includes a timer.

3. A verification instrument as claimed in claim 1, wherein said power circuit includes a power switch, an AC output interface and an AC/DC module for adapting the required power for instrument conversion.

4. The prover of claim 1 wherein the outlet voltage acquisition circuit includes a voltage divider resistor and an operational amplifier for coupling the divided signal source to the microprocessor.

5. The checking instrument according to claim 1, wherein the key input circuit includes four keys using a "common negative" connection, a "confirm" key for opening or closing any one of the detection channels, an "flip up" key and a "flip down" key for switching the detection channels back and forth, and a "reset" key for clearing the detection result.

6. The calibration instrument of claim 1, wherein said signal transmission isolation circuit is an opto-isolator circuit comprising a current limiting resistor and an opto-isolator loop.

7. A method for verifying an outlet verification instrument of a relay protection device according to claim 2, comprising the steps of:

(1) the outlet voltage acquisition circuit divides the acquired voltage by adopting a high resistance, reduces the influence of the acquisition circuit on a signal source and ensures the integrity of the signal to the greatest extent;

(2) and (3) utilizing the optical coupling isolation to transmit to a microprocessor for operation judgment: the microprocessor performs coefficient matching on the acquired analog signals through a self-contained analog quantity acquisition channel to finally obtain the voltage at the lower end of the pressing plate in the action process and judge whether the checked outlet voltage is in a normal setting range; if the signal is not in the normal setting range, the microprocessor sends a signal to drive a buzzer control circuit to give an alarm;

(3) the microprocessor counts by using an internal timer, and performs logical operation and sequencing on a plurality of detection channel values transmitted by the optical coupling isolation circuit to obtain the action time and the action sequence of the plurality of pressing plates;

(4) driving the LED lamp to realize synchronous lighting of a logic operation result and the corresponding LED lamp bead; and simultaneously controlling the liquid crystal screen to display the condition of the current acquisition channel, comprising the following steps: the time of the action, the sequence of the action, and the voltage in real time;

(5) and resetting the test result, resetting the test result in the current round, and carrying out second test preparation in the next round.

8. The verification method of claim 7, wherein in step (1), the high impedance voltage division is performed when the signal input impedance is greater than 10 mega ohms.

9. The verification method according to claim 7, wherein the microprocessor is an STM32F103 single chip microcomputer and has the following functions: analog quantity sampling, internal calculation, data storage, clock reading, logic judgment, signal output, liquid crystal display, LED display driving and fault judgment output.

10. The calibration method according to claim 7, wherein the LED driving display circuit is used for synchronously displaying whether the outlet pressure plate acts in real time, and is driven by a Darlington power tube, and the connection of the common cathode is adopted; after the detection is started, the LED lamp beads are kept normally on in a self-locking mode, and the LED lamp beads are extinguished to wait for the next round of test after reset.