Circuit breaker transmission test protection analyzer and working method thereof

Abstract

The invention discloses a circuit breaker transmission test protection analyzer and a working method thereof, and relates to the technical field of electronic instruments.The circuit breaker transmission test protection analyzer comprises a shell, a Hall sensor, a processing module, a protection module and a display screen are arranged in the shell, the input end of the Hall sensor is connected with a circuit breaker opening and closing loop, and the output end of the Hall sensor is connected with the processing module; the processing module is connected with the protection module which is connected with the circuit breaker opening and closing loop, and the processing module is connected with the display screen. The device is mainly applied to the transmission test of the high-voltage circuit breaker, the tripping and closing coil of the circuit breaker is protected and analyzed, and the tripping and closing coil of the circuit breaker is convenient to overhaul, maintain and replace.

Description

Technical Field

[0001] The invention relates to the technical field of electronic instruments and meters, and in particular to a circuit breaker transmission test protection analyzer and a working method thereof. Background Art

[0002] A circuit breaker is a switching device that can close, carry and interrupt current under normal circuit conditions and can close, carry and interrupt current under abnormal circuit conditions within a specified time.

[0003] The circuit breaker tripping and closing coil is mainly composed of a coil, an iron core, and an armature. When the coil is energized, an electromagnetic force is generated to attract the armature. Through the simplification of the physical model, the coil can be regarded as an RL series circuit. When the circuit breaker tripping and closing coil is aged, damaged, or the circuit breaker is stuck, the operating current characteristics of the tripping and closing coil will also change. Although the waveform of the coil after aging is very similar to the waveform in the normal state, the overall amplitude is reduced; when the circuit breaker mechanism is stuck, the waveform is flat and lacks peak and valley characteristics.

[0004] During the transmission and remote control tests of substation circuit breakers, circuit breakers may trip due to reasons such as mechanism jamming, coil aging, and improper human operation. At this time, the circuit breaker tripping and closing coils are energized and conductive for a long time, which can easily burn the coils. At the same time, in many substations that have been in operation for a long time, the circuit breaker tripping and closing coils have varying degrees of aging and damage, and it is difficult for operation and maintenance personnel to determine whether the coils are aged and damaged through appearance and routine tests. If the aged or damaged coils are not replaced in time, it will pose a huge hidden danger to the safe and stable operation of the power grid.

[0005] In order to prevent the tripping and closing coil from burning out during the circuit breaker transmission test and to analyze whether the circuit breaker tripping and closing coil is aging and damaged, a circuit breaker transmission test protection analyzer was developed. Summary of the invention

[0006] The technical problem to be solved by the present invention is to solve the deficiencies in the prior art and to design a new circuit breaker transmission test protection analyzer. The circuit breaker transmission test protection analyzer has a perfect structure and solves the problem that when the circuit breaker is in motion, the circuit breaker tripping and closing coil is energized for a long time and the coil is easily damaged. At the same time, it solves the problem that the circuit breaker is aging or damaged, but the operation and maintenance personnel fail to discover it in time, which poses a huge hidden danger to the safe and stable operation of the power grid.

[0007] The solution adopted by the present invention to solve the technical problem is:

[0008] A circuit breaker transmission test protection analyzer comprises a housing, wherein a Hall sensor, a processing module, a protection module and a display screen are arranged inside the housing;

[0009] The Hall sensor is used to collect the circuit current of the circuit breaker.

[0010] The processing module is used to convert the collected current and process the converted current.

[0011] The protection module is used to control the circuit breaker control circuit breakage and protect the tripping and closing coil from being burned.

[0012] The display screen outputs the current of the circuit breaker opening and closing circuit in the form of a waveform.

[0013] The input end of the Hall sensor is connected to the circuit breaker opening and closing circuit, the output end of the Hall sensor is connected to the processing module, the processing module is connected to the protection module, the protection module is connected to the circuit breaker opening and closing circuit, and the processing module is connected to the display screen.

[0014] As a preferred implementation manner of the present invention, the Hall sensor is provided with a first input end and a second input end, the first input end is connected to a circuit breaker closing circuit, and the second input end is connected to a circuit breaker opening circuit.

[0015] As a preferred embodiment of the present invention, the processing module includes an AD analog-to-digital converter and an STM32 single-chip microcomputer, the input end of the AD analog-to-digital converter is connected to the output end of the Hall sensor, and the output end of the AD analog-to-digital converter is connected to the input end of the STM32 single-chip microcomputer;

[0016] The AD converter performs analog-to-digital conversion on the collected current.

[0017] The STM32 single chip microcomputer processes the converted current.

[0018] As a preferred embodiment of the present invention, the protection module comprises a common cathode diode, a time-delay protection relay and an optical coupling relay, the anode of the common cathode diode is respectively connected in parallel with the circuit breaker closing circuit and the circuit breaker opening circuit, the cathode of the common cathode diode is connected in series with the time-delay protection relay, the time-delay protection relay is connected in series with the negative current of the circuit breaker control circuit, and the optical coupling relay is connected in series with the circuit breaker control circuit;

[0019] As a preferred embodiment of the present invention, the time delay protection relay is provided with normally closed nodes SJ, SJ, and the optocoupler relay is provided with normally closed nodes GO and GO;

[0020] The normally closed node SJ of the time delay relay is connected in series to the circuit breaker closing circuit, the normally closed node SJ of the time delay relay is connected in series to the circuit breaker opening circuit, the normally closed node GO of the optocoupler relay is connected in series to the circuit breaker closing circuit, and the normally closed node GO of the optocoupler relay is connected in series to the circuit breaker opening circuit.

[0021] As a preferred implementation manner of the present invention, the STM32 single chip microcomputer is connected to an amplifier circuit, and the amplifier circuit is connected to the optocoupler relay.

[0022] As a preferred implementation manner of the present invention, the STM32 single-chip microcomputer auxiliary interface is connected to a mobile memory.

[0023] As a preferred embodiment of the present invention, a working method of a circuit breaker transmission test protection analyzer comprises the following steps:

[0024] S1. The Hall sensor collects current and transmits the digital value of the current to the STM32 microcontroller through AD digital-to-analog conversion;

[0025] S2. If the current is normal and has not exceeded the time limit, the circuit breaker control circuit is normal and the circuit breaker operates normally. If the current exists for a long time, the time-delay protection relay reaches the time setting value and operates, the normally closed node is disconnected, and the circuit breaker control circuit is disconnected;

[0026] S3. The STM32 microcontroller outputs a high level or a low level by judging the current. When the current is too large, the STM32 microcontroller outputs a high level, controls the action of the optocoupler relay through the amplifier circuit, disconnects the normally closed node, and breaks the control circuit.

[0027] The stream is recorded and processed, and sent to the display screen to display the waveform. The experimental data is stored in the mobile storage device, and can also be connected to the computer through the serial port for human-computer interaction.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. Connect a common cathode diode in parallel in the circuit of the circuit breaker, connect a delay relay between the cathode of the common cathode diode and the negative power of the control circuit, and connect the normally closed node of the delay relay in series to the circuit of the circuit breaker. If the circuit breaker needs to be driven but the circuit breaker moves within a certain period of time, the normally closed node of the delay relay will be disconnected and the circuit breaker control circuit will be disconnected, thereby achieving the effect of delaying the protection of the circuit breaker tripping and closing coil.

[0030] 2. Connect the normally closed nodes of the optocoupler relay in series to the circuit breaker opening and closing circuits. The STM32 microcontroller outputs a high / low level to control the optocoupler relay. When the current input by the STM32 microcontroller is large, it outputs a high level to trigger the optocoupler relay. The normally closed node of the optocoupler relay is disconnected, and the circuit breaker control circuit is disconnected, thereby achieving the effect of protecting the circuit breaker from tripping the closing coil due to excessive impact current.

[0031] 3. The STM32 microcontroller is connected to a display screen. The STM32 microcontroller can process the collected current and output it to the display screen in the form of an image. It can be intuitively compared with the normal current waveform when the coil is energized, helping the inspection personnel to analyze whether the coil is aging or damaged.

[0032] 4. The STM32 microcontroller is connected to a mobile memory. The STM32 microcontroller can process the collected current and store it through the mobile memory. It can save multiple test results, which is conducive to comparative analysis and improves the inspection personnel's judgment on the coil characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of an existing circuit breaker control circuit;

[0034] Figure 2 A schematic diagram of a circuit breaker transmission test protection analyzer proposed by the present invention;

[0035] Figure 3 A logic diagram of the circuit breaker transmission test protection analyzer proposed by the present invention;

[0036] Figure 4 A physical picture of the circuit breaker transmission test protection analyzer proposed by the present invention;

[0037] Figure 5 This is a physical picture of the circuit breaker transmission test protection analyzer proposed in the present invention.

[0038] Reference numerals

[0039] 1-Hall sensor, 2-processing module, 3-protection module, 4-display screen, 5-amplification circuit, 6-mobile memory, 20-AD analog-to-digital converter 20, 21-STM32 microcontroller 21, 30-common cathode diode, 31-delay protection relay. DETAILED DESCRIPTION

[0040] The specific implementation of the present invention is described below in conjunction with the accompanying drawings and embodiments:

[0041] It should be noted that the structures, colors, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them, and are not used to limit the conditions under which the present invention can be implemented. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0042] At the same time, in the description of the present invention, it should be understood that the terms "one end", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "two ends" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0043] In addition, the terms "first", "second", "third" and "fourth" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first", "second", "third" and "fourth" may explicitly or implicitly include at least one of such features.

[0044] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0045] like Figure 1 As shown in the figure, in the circuit breaker control circuit, the protection part of the coil is only the circuit breaker auxiliary node. When the circuit breaker refuses to operate, the corresponding auxiliary node of the tripping and closing coil is not disconnected, and the protection coil loses its function. Especially for old equipment, it is easy to burn out the coil during the transmission process. According to the characteristics of the circuit breaker tripping and closing coil, and considering the risk of burning out the coil in the circuit breaker transmission test, it is decided to develop a Figure 2 Circuit breaker transmission test protection analyzer shown.

[0046] like Figure 2 As shown, the circuit breaker transmission test protection analyzer of the present invention comprises a shell, and a Hall sensor 1, a processing module 2, a protection module 3 and a display screen 4 are arranged inside the shell, the input end of the Hall sensor 1 is connected to the circuit breaker opening and closing circuit, the output end of the Hall sensor 1 is connected to the processing module 2, the processing module 2 is connected to the protection module 3, the protection module 3 is connected to the circuit breaker opening and closing circuit, and the processing module 2 is connected to the display screen 4;

[0047] The Hall relay is installed in the opening and closing circuit, collects the current of the opening and closing circuit, and sends the processed data to the processing module 2. The processing module 2 analyzes and processes the data sent by the Hall sensor 1, and sends a signal to the protection module 3 after processing. The protection module 3 controls the circuit breaker control circuit and sends the processed data to the display screen 4 at the same time. The state of the coil can be judged intuitively, which helps the operation and maintenance personnel analyze whether the coil is aged or damaged. The display screen 4 outputs the current of the opening and closing circuit in the form of a waveform.

[0048] The Hall sensor 1 is provided with a first input end and a second input end, the first input end is connected to the closing circuit of the circuit breaker, and the second input end is connected to the opening circuit of the circuit breaker. The Hall sensor 1 is provided with the first input end and the second input end to accurately detect the state of the circuit breaker. By connecting the two input ends of the Hall sensor 1 to the closing circuit and the opening circuit of the circuit breaker respectively, the opening and closing states of the circuit breaker can be accurately detected, thereby better protecting the circuit breaker. At the same time, it can respond quickly and detect the opening and closing states of the circuit breaker in a short time, thereby taking protective measures in time.

[0049] The processing module 2 includes an AD analog-to-digital converter 20 and an STM32 single-chip microcomputer 21. The input end of the AD analog-to-digital converter 20 is connected to the output end of the Hall sensor 1, and the output end of the AD analog-to-digital converter 20 is connected to the input end of the STM32 single-chip microcomputer 21. The combination of the AD analog-to-digital converter 20 and the STM32 single-chip microcomputer 21 can realize accurate processing of signals, reduce errors and interference, and improve the self-protection ability and fault diagnosis ability of the equipment, making the entire system more stable and reliable.

[0050] The AD converter performs analog-to-digital conversion on the collected current and converts the data into a format readable by the STM32 single-chip microcomputer 21. The STM32 single-chip microcomputer 21 processes the converted current. The STM32 single-chip microcomputer 21 has the characteristics of high performance and low power consumption, can process data quickly and accurately, and improves data processing efficiency. At the same time, the STM32 single-chip microcomputer 21 has rich peripheral interfaces, which can be more conveniently connected and communicated with other components, so that the device can expand more functions and applications.

[0051] The protection module 3 comprises a common cathode diode 30, a time-delay protection relay 31 and an optocoupler relay. The anode of the common cathode diode 30 is respectively connected in parallel with the circuit breaker closing circuit and the circuit breaker opening circuit. The cathode of the common cathode diode 30 is connected in series with the time-delay protection relay 31. The time-delay protection relay 31 is connected in series with the negative current of the circuit breaker power supply circuit. The optocoupler relay is connected in series with the circuit breaker control circuit.

[0052] (1) The common cathode diode 30 can prevent the circuit breaker from malfunctioning due to the reverse potential of the circuit breaker opening and closing circuit;

[0053] (2) The time-delay protection relay 31 cooperates with its normally closed node to prevent the tripping and closing coil from burning out due to long-term power failure;

[0054] (3) The optocoupler relay receives data transmitted by the STM32 microcontroller 21 and cooperates with its normally closed node to prevent the tripping coil from burning out due to a large current.

[0055] The protection module 3 is provided with triple protection to realize multiple protections for the circuit breaker.

[0056] The time delay protection relay 31 is provided with normally closed nodes SJ1 and SJ2, and the optocoupler relay is provided with normally closed nodes GO1 and GO2;

[0057] The normally closed node SJ1 of the time delay protection relay 31 is connected in series to the circuit breaker closing circuit, the normally closed node SJ2 of the time delay protection relay 31 is connected in series to the circuit breaker opening circuit, the normally closed node GO1 of the optocoupler relay is connected in series to the circuit breaker closing circuit, and the normally closed node GO2 of the optocoupler relay is connected in series to the circuit breaker opening circuit.

[0058] The time delay protection relay 31 is provided with normally closed nodes SJ1 and SJ2, and the optocoupler relay is provided with normally closed nodes GO1 and GO2. The cathode corresponding to the common cathode diode 30 is connected to the circuit breaker opening and closing circuit. At the same time, the normally closed nodes corresponding to the time-delay protection relay 31 and the optocoupler relay are connected to the circuit breaker opening and closing circuits, and the common cathode diode 30 and the time-delay protection relay 31 are connected in parallel to the opening and closing circuits. When the opening and closing time exceeds the fixed time, the time-delay protection relay 31 is activated to disconnect the opening and closing circuits to protect the tripping and closing coils from burning; the input end of the Hall sensor 1 is connected to the opening and closing circuits, and the output end is connected to the STM32 single-chip microcomputer 21 after conversion by the AD converter. The collected data is analyzed by the STM32 single-chip microcomputer 21, and the signal is released through the output port to start the optocoupler relay. The normally closed contacts GO1 and GO2 of the optocoupler relay are respectively connected to the closing circuit and the opening circuit. When the current collected by the Hall sensor 1 is greater than the fixed value, the STM32 single-chip microcomputer 21 drives the optocoupler relay, the normally closed node of the optocoupler relay is opened, the opening and closing circuits are disconnected, and the tripping and closing coils are protected from burning.

[0059] The output port of the STM32 single-chip computer 21 is connected to an amplifier circuit 5, and the amplifier circuit 5 is connected to an optocoupler relay. The pin 21 of the STM32 single-chip computer can output a current of 4-20mA. Directly connecting the optocoupler relay may affect the reliability of control. Connecting the amplifier circuit 5 can amplify the signal output by the STM32 single-chip computer 21, so that the signal can effectively control the optocoupler relay. Since the control signal of the optocoupler relay often requires a large current, the control ability of the signal can be enhanced by the amplifier circuit 5, so that the optocoupler relay can operate reliably.

[0060] The auxiliary interface of the STM32 single-chip computer 21 is connected to a mobile memory 6, which can store the current data of the opening and closing circuits in batches and save multiple test results, which is conducive to comparative analysis and improves the inspection personnel's judgment on the coil characteristics. In addition, connecting the mobile memory 6 through the auxiliary interface can also improve the flexibility and maintainability of the present invention. When a device fails, the backup data in the mobile storage device can be used to perform fault analysis, thereby solving the equipment failure problem more quickly and improving the reliability and stability of the equipment.

[0061] Advantages of using common cathode diode 30:

[0062] (1) The common cathode diode 30 has relatively stable performance and can effectively prevent malfunction caused by voltage fluctuation, electromagnetic interference, etc.

[0063] (2) The common cathode diode 30 has good temperature characteristics and can ensure stable operation under various temperature conditions.

[0064] (3) The common cathode diode 30 has a fast response time and can quickly absorb overvoltage and overcurrent, thereby protecting the circuit breaker from damage.

[0065] (4) Since the common cathode diode 30 has a relatively simple structure, it can be easily replaced and repaired when a fault occurs, thereby improving the maintainability of the equipment.

[0066] The STM32 microcontroller 21 preferably selects models that can realize serial port communication, such as STM32F103C8T6, STM32F407ZGT6, etc. Through serial port communication, the STM32 microcontroller 21 can communicate with the computer to realize human-computer interaction, which is convenient for direct analysis of coil characteristics on site.

[0067] like Figure 1 As shown in the figure, in the circuit breaker control circuit, the protection part of the coil only has the circuit breaker auxiliary node. When the circuit breaker refuses to operate, the corresponding auxiliary node of the tripping and closing coil is not disconnected, and the protection coil loses its function. Figure 2 This is the circuit breaker control circuit diagram after optimization during the test. Figure 2 , analyze the working method of circuit breaker transmission test protection analyzer:

[0068] 1. When the circuit breaker transmission command is issued, the circuit breaker control circuit is turned on and current appears in the circuit;

[0069] 2. The Hall sensor 1 collects current and transmits the digital value of the current to the STM32 microcontroller 21 through the AD digital-to-analog converter 20;

[0070] 3. If the current is normal and has not exceeded the time limit, the control circuit is normal and the circuit breaker operates normally. If the current exists for a long time, the time-delay protection relay 31 reaches the time setting value and operates, the normally closed node is disconnected, the control circuit is disconnected, and the protection coil is not burned;

[0071] 4. The STM32 microcontroller 21 outputs a high level or a low level by judging the current. When the current is too large, the STM32 microcontroller 21 outputs a high level, controls the action of the optocoupler relay through the amplifier circuit 5, disconnects the normally closed node, and breaks the control circuit to protect the coil from being burned;

[0072] 5. Finally, the STM32 microcontroller 21 processes the current records of the entire process and sends them to the display screen 4 to display the waveform. It also stores the experimental data through a mobile storage peripheral and can also connect to a computer through a serial port for human-computer interaction.

[0073] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

[0074] Many other changes and modifications may be made without departing from the concept and scope of the present invention.It should be understood that the present invention is not limited to the specific embodiments, and the scope of the present invention is defined by the appended claims.

Claims

1. A circuit breaker transmission test protection analyzer, comprising a housing, characterized in that: A Hall sensor (1), a processing module (2), a protection module (3) and a display screen (4) are arranged inside the housing; The Hall sensor (1) is used to collect the circuit current of the circuit breaker. The processing module (2) is used to convert the collected current and process the converted current. The protection module (3) is used to control the circuit breaker control circuit to prevent the circuit breaker from being broken and to protect the tripping and closing coil from being burned. The display screen (4) outputs the current of the circuit breaker opening and closing circuit in the form of a waveform. The input end of the Hall sensor (1) is connected to the circuit breaker opening and closing circuit, the output end of the Hall sensor (1) is connected to the processing module (2), the processing module (2) is connected to the protection module (3), the protection module (3) is connected to the circuit breaker opening and closing circuit, and the processing module (2) is connected to the display screen (4).

2. The circuit breaker transmission test protection analyzer according to claim 1, characterized in that: The Hall sensor (1) is provided with a first input end and a second input end, the first input end is connected to a circuit breaker closing circuit, and the second input end is connected to a circuit breaker opening circuit.

3. The circuit breaker transmission test protection analyzer according to claim 1, characterized in that: The processing module (2) comprises an AD analog-to-digital converter (20) and an STM32 single-chip microcomputer (21), wherein the input end of the AD analog-to-digital converter (20) is connected to the output end of the Hall sensor (1), and the output end of the AD analog-to-digital converter (20) is connected to the input end of the STM32 single-chip microcomputer (21); The AD converter (20) performs analog-to-digital conversion on the collected current. The STM32 single chip computer (21) processes the converted current.

4. The circuit breaker transmission test protection analyzer according to claim 1, characterized in that: The protection module (3) comprises a common cathode diode (30), a time-delay protection relay (31) and an optical coupling relay; the anode of the common cathode diode (30) is respectively connected in parallel with a circuit breaker closing circuit and a circuit breaker opening circuit; the cathode of the common cathode diode (30) is connected in series with the time-delay protection relay (31); the time-delay protection relay (31) is connected in series with the negative current of the circuit breaker control circuit; and the optical coupling relay is connected in series with the circuit breaker control circuit.

5. The circuit breaker transmission test protection analyzer according to claim 4, characterized in that: The time delay protection relay (31) is provided with normally closed nodes SJ1 and SJ2, and the optocoupler relay is provided with normally closed nodes GO1 and GO2; The normally closed node SJ1 of the time delay protection relay (31) is connected in series to the circuit breaker closing circuit, the normally closed node SJ2 of the time delay protection relay (31) is connected in series to the circuit breaker opening circuit, the normally closed node GO1 of the optical coupling relay is connected in series to the circuit breaker closing circuit, and the normally closed node GO2 of the optical coupling relay is connected in series to the circuit breaker opening circuit.

6. The circuit breaker transmission test protection analyzer according to claim 3, characterized in that: The STM32 single-chip computer (21) is connected to an amplifier circuit (5), and the amplifier circuit (5) is connected to the optical coupler relay.

7. The circuit breaker transmission test protection analyzer according to claim 3, characterized in that: The auxiliary interface of the STM32 single-chip computer (21) is connected to a mobile memory (6).

8. A working method of a circuit breaker transmission test protection analyzer, characterized in that: The circuit breaker transmission test protection analyzer as claimed in any one of claims 1 to 7 comprises the following steps: S1. The Hall sensor (1) collects current and transmits the digital value of the current to the STM32 microcontroller (21) through AD digital-to-analog conversion (20); S2. If the current is normal and has not timed out, the circuit breaker control circuit is normal and the circuit breaker operates normally. If the current exists for a long time, the time delay protection relay (31) reaches the time setting value and operates, the normally closed node is disconnected, and the circuit breaker control circuit is disconnected; S3. The STM32 single chip microcomputer (21) outputs a high level or a low level by judging the magnitude of the current. When the current is too large, the STM32 single chip microcomputer (21) outputs a high level, controls the operation of the optical coupler relay through the amplifier circuit, disconnects the normally closed node, and breaks the control circuit; S4. Finally, the STM32 single chip microcomputer (21) processes the current records of the entire process and sends them to the display screen (4) to display the waveform, and stores the experimental data in a mobile memory and connects to a computer through a serial port for human-computer interaction.

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