CN211426651U - A relay protection device outlet calibration instrument - Google Patents

Abstract

The utility model relates to the technical field of electric power systems, in particular to a relay protection device outlet calibration instrument for the regular inspection outlet calibration link of a relay protection device of an electric power system. It includes a casing and 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, a buzzer alarm circuit and a key input circuit arranged in the casing; the outlet voltage acquisition circuit The circuit, the signal transmission isolation circuit and the central processing unit are connected in sequence, and the central processing unit is also connected to the LED drive display circuit, the liquid crystal display circuit, the buzzer alarm circuit, the key input circuit and the power supply circuit, respectively. The circuit is also connected to the LED driving display circuit, the liquid crystal display circuit and the buzzer alarm circuit respectively. The utility model reduces auxiliary instruments, simplifies the testing process, and improves the testing accuracy.

Description

A relay protection device outlet calibration instrument

technical field

The utility model relates to the technical field of electric power systems, in particular to a relay protection device outlet calibration instrument for the regular inspection outlet calibration link of a relay protection device of an electric power system.

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 all the relay protection devices are inspected, the on-off status of the output contacts (outlets) that are put into use must be checked in turn. "

At present, due to various reasons such as various types of substation protection devices, large workload of regular inspection, misoperation of staff, device failure, etc., the export verification of substation protection devices has resulted in "misdetection" and "missing inspection", resulting in the protection device "running with illness". ”, “misoperation”, “no export” and other accidents occur from time to time.

The protection device outlet calibrator is mainly used to detect the potential and time of the lower end of the outlet pressure plate in the protection outlet link during the transmission process of the protection device, and independently judge whether it is consistent with the setting of the protection device. When the order and time of the protection outlet are different from the setting of the protection setting, the wrong outlet will be caused, resulting in a large-scale power failure.

Existing relay protection testers (such as Onli, Relay 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. To the verification of the protection outlet pressure plate, usually use a multimeter to measure the potential of the lower end of the outlet pressure plate during the transmission process, and rely on the visual observation of the successive changes of the numbers to determine the successive actions of each outlet.

Using a manual multimeter requires at least two people to complete the test work, which is redundant and inefficient. For a protection device with a single outlet, it is easy to use the observation multimeter for verification; for a protection device with multiple outlets, multiple multimeters are required to measure the potential of 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. The phenomenon of poor contact occurs. Secondly, multiple multimeters must be of the same model. The inherent delay of the different models of meters in the acquisition process is different, and there are errors that affect the final judgment result. Because the internal nodes of the protection device act quickly, 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. When observing the potential of multiple protection outlet pressure plates at the same time, the observation results are prone to inaccuracy and miscalibration. test phenomenon. Usually the verification process requires multiple measurements, and the final summary test results take the maximum distribution.

Therefore, the existing testing 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 testing process requires a high level of observation of the instrument and the human eye, which is limited It is relatively large; at the same time, the test process requires multiple measurements, which has disadvantages such as low efficiency.

Utility model content

Aiming at the above-mentioned prior art, the purpose of this utility model is to provide a relay protection device outlet calibration instrument, an instrument that accurately judges and calculates the potential and time of the lower end of the outlet pressure plate during the transmission process of the protection device, and detects and calculates The calculation results are displayed in real time.

In order to achieve the above object, the utility model has adopted the following technical solutions:

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

The operating panel of the casing is provided with a power switch, a grounding terminal plug, an AC input plug, a test button, a liquid crystal display screen, an LED light and a number of 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 the control of the LED drive display circuit, the liquid crystal display circuit, and the 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 supply 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 divided by the large resistor to the microprocessor.

Further, the described key input circuit includes four keys using the "common cathode" connection method, which are respectively the "confirm" key for opening or closing any detection channel, and the "up" key and the "down" key for switching the detection channel back and forth. "Turn" key, and "Reset" key to clear the test result.

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 backup 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 wire clip.

Beneficial effects:

(1) The use of the calibration instrument of the present utility model does not need to rely entirely on the observation of the human eye and the multimeter. When performing multi-outlet calibration, the auxiliary instruments are greatly reduced, and the testing process is simplified; Delay, resulting in inaccurate detection caused by errors in test results.

(2) The testing instrument of the utility model adopts the outlet voltage collection circuit, which can collect multiple outlet voltages at the same time, isolate the transmission process through the optocoupler, and transmit it to the microprocessor for identification and judgment, so as to minimize the interference factors, and The human observation and judgment link in the middle is omitted, and the accuracy of the test process is improved.

(3) At least two people are required to perform the export verification in the traditional way; one of them is to perform the output of the relay tester, and the other is to connect the multimeter pen and observe the change of the multimeter. The testing instrument of the utility model adopts an integrated design, and the outlet calibrator independently completes the potential detection of each outlet pressure plate, realizes the judgment of the action sequence of each pressure plate through the internal program of the microprocessor, and performs real-time monitoring through the liquid crystal display screen and the LED light. show.

(4) With the help of the timer inside the microprocessor, the testing instrument of the present utility model calculates the time from the start of transmission to the output stage of the pressure plate, so as to achieve the purpose of checking with the setting value of the device, and further improve the reliability of the device operation.

(5) The outlet voltage acquisition circuit adopted by the testing instrument of the present utility model will not induce the “DC closed loop” fault when performing the outlet verification of the protection devices powered by two sets of DC power sources at the same time, and the verification process will not affect the substation’s operation. The DC system operates normally.

Description of drawings

Fig. 1 is the plan view of the protection device outlet calibration instrument;

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

Figure 3 is a schematic diagram of the internal circuit of the microprocessor;

Figure 4 is a schematic diagram of an outlet voltage acquisition circuit;

5 is a schematic diagram of a key circuit;

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

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

Figure 8 is a schematic diagram of a buzzer alarm circuit;

9 is a schematic diagram of a power supply circuit;

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

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

Detailed ways

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

Example 1

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

As shown in Figure 2, the circuit in the magnesium-aluminum alloy casing 22 of the calibration instrument includes 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 connected in sequence, and the central processing unit is also 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, 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, which are used to complete the logic algorithm processing of the collected signals and control the LED drive display circuit, the liquid crystal display circuit, and the 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 supply for the instrument. When the power switch 7 is closed, the AC 220V supply device is converted into 12V through the AC/DC module to supply power to the instrument, the 12V DC is regulated to +3.3V DC for the microprocessor, and the 12V DC is regulated by the voltage regulator chip to become +5V DC power supply for 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 sampling circuits. The acquisition front end uses a large resistor to divide the voltage (signal input impedance exceeds 10 megaohms), and the sampling circuit can be divided The impact on the signal source is minimized and the integrity of the signal is ensured to the greatest extent. Since the GND of the power equipment ±110V signal source is generally grounded with high resistance, the use of large resistance voltage divider processing can ensure that the most real voltage signal is sampled. And when the two sets of DC systems are powered by the protection device outlet verification at the same time, the "DC closed loop" 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 divided by the large resistance is too high, so it cannot directly enter the analog sampling port of the microprocessor. This will cause the impedance of the signal source to not match the impedance of the analog port of the microprocessor. The voltage value sampled by the microprocessor is Abnormal, affecting the final export verification accuracy. This instrument uses TLC2274 operational amplifier for first-level impedance matching, which converts high-impedance signals into low-impedance signals and then enters 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 achieves the effect of impedance matching during 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. lead to damage to the pins of the microcontroller.

As shown in Figure 5, the described key 4 input circuit includes four keys 4 using the "common cathode" connection method, which are respectively the "confirm" key for opening or closing any detection channel, and the "upturn" key for switching the detection channel back and forth. " key and "down" key, and "reset" key for clearing the test result. Press the "Reset" button to clear the test results 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 being divided by the internal resistance cannot be directly sent to the logic operation unit, resulting in electromagnetic interference and signal fluctuations. All will affect the operation and judgment of the logic operation unit on the small voltage signal. The optocoupler isolation circuit is used, and the external output voltage signal drives the light-emitting diode. The internal detection of light emission is amplified and transmitted to the microprocessor to isolate the external signal from the voltage acquisition signal. interference.

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

As shown in FIG. 8 , the buzzer alarm circuit includes: a transistor 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 and action time of each acquisition channel, as well as the action sequence of each outlet during the transmission process. With the input circuit of button 4, the closing or operation of each acquisition channel can be completed. open. The liquid crystal display screen 3 is directly connected with the output control of the microprocessor, as shown in FIG. 10 .

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

The main software flow of the software program module is as follows:

1. The system is initialized and self-checked, and the 16-channel LED light 1 is turned on to display the initial power-on screen. After a delay of about 3 seconds, the 16-channel LED light 1 is turned off to display 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) confirm whether the button 4 is pressed, (4) the reset button 4 is pressed, (5) whether the AD sampling mark arrives (every 1ms), (6) whether the round verification end mark arrives (30 seconds after the reset is pressed), as shown in Figure 11.

To sum up, the beneficial effects of this embodiment are:

(1) The use of the calibration instrument of the present utility model does not need to rely entirely on the observation of the human eye and the multimeter. When performing multi-outlet calibration, the auxiliary instruments are greatly reduced, and the testing process is simplified; Delay, resulting in inaccurate detection caused by errors in test results.

(2) The testing instrument of the utility model adopts the outlet voltage collection circuit, which can collect multiple outlet voltages at the same time, isolate the transmission process through the optocoupler, and transmit it to the microprocessor for identification and judgment, so as to minimize the interference factors, and The human observation and judgment link in the middle is omitted, and the accuracy of the test process is improved.

(3) At least two people are required to perform the export verification in the traditional way; one of them is to perform the output of the relay tester, and the other is to connect the multimeter pen and observe the change of the multimeter. The testing instrument of the utility model 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 internal program of the microprocessor. real-time display.

(4) With the help of the timer inside the microprocessor, the testing instrument of the present utility model calculates the time from the start of transmission to the output stage of the pressure plate, so as to achieve the purpose of checking with the setting value of the device, and further improve the reliability of the device operation.

(5) The outlet voltage acquisition circuit adopted by the testing instrument of the present utility model will not induce the “DC closed loop” fault when performing the outlet verification of the protection devices powered by two sets of DC power sources at the same time, and the verification process will not affect the substation’s operation. The DC system operates normally.

(6) The shell 2 of the device panel adopts the aluminum-magnesium alloy shell 2, which has strong anti-electromagnetic interference ability and improves the stability of the device.

Embodiment 2

A calibration method based on the above-mentioned relay protection device outlet calibration instrument, 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 operation 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 carries out the calculation. Judging whether the verified outlet voltage is within the normal setting range, if it is not within the normal setting range, the microprocessor sends a signal to drive the buzzer control circuit to give an alarm;

(3) The microprocessor then uses the internal timer to count, performs logical operation and sorting on the values of several detection channels transmitted by the optocoupler isolation circuit, and obtains the action time and sequence of actions of the above-mentioned several pressure plates;

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

(5) "Reset" the above test results, clear the current round of test results, and prepare for the next round of second test.

In step (1), when the signal input impedance is greater than 10 megaohms, a high-resistance voltage divider is performed.

The microprocessor is STM32F103 single-chip microcomputer, which has the following functions: analog 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 the "common cathode" connection method; after starting the detection, the LED light 1 bead is self-locking and keeps on, and after resetting, it goes out and waits for the next round test.

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

To sum up, the beneficial effects of this embodiment are:

(1) The use of high-impedance and 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 whole process of the potential change of the lower end of the pressure plate during the transmission process can be accurately recorded, and the accurate judgment of the action sequence of the protection pressure plate can be realized, avoiding the hidden danger of human error verification and misjudgment, and improving the protection device. operational reliability;

(3) It adopts integrated design and one-button operation, which greatly reduces manpower input, reduces intermediate links, and greatly shortens the time required for the export verification link, thereby shortening the time for the entire protection inspection. According to statistics, the instrument has completed The average time for all the outlet verification links of a group of 220kV transformer protection devices is 1.9 hours. Compared with the traditional method, the average time saved is 1.7 hours.

(4) The logic judgment adopts the first "protection exit node action judgment algorithm" in the industry. Through software simulation, machine simulation, and 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 strong reference significance.

In short, the "integrated design" of the protection device exit calibrator of the present invention can greatly reduce the participation of maintenance personnel, and the "one-key operation" can shorten the intermediate redundant links and reduce interference factors; It realizes high-precision acquisition and high-efficiency calculation and judgment, saves the unnecessary number of test operations, greatly shortens the test time, and improves the accuracy of the detection process; adds an alarm loop to test the change of the DC system voltage in the station during the whole process; export Potential and time check to improve the reliability of the protection device operation.

The above are only preferred specific embodiments of the present utility model, but the protection scope of the present utility model is not limited thereto. The technical solution and the utility model concept of the invention are equivalently replaced or changed, which are all included in the protection scope of the present invention.

Claims (6)

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; and the operating panel of the 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.

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