CN209803292U - transformer direct-current resistance and on-load tap-changer comprehensive test device - Google Patents

Abstract

the utility model relates to a transformer direct current resistance and on-load tap-changer comprehensive test device, belonging to the technical field of transformer direct current resistance and on-load tap-changer comprehensive test devices; the technical problem to be solved is as follows: providing a transformer direct-current resistance and on-load tap-changer comprehensive testing device; the technical scheme for solving the technical problem is as follows: the LED display cabinet comprises a cabinet body, wherein the front surface of the cabinet body is provided with an LED display screen and a control button; one side of the box body is provided with a high-voltage test port and a low-voltage test port, and the other side of the box body is provided with a power supply module, a data communication module and a constant current source module; a control circuit board is arranged in the box body, a central controller is integrated on the control circuit board, and the central controller is respectively connected with the LED display screen, the control button, the data communication module and the constant current source module through wires; the data communication module is connected with the wireless temperature probe through a wireless network; the utility model discloses be applied to the place of measuring transformer direct current resistance.

Description

A comprehensive test device for DC resistance of transformer and on-load tap changer

technical field

The utility model relates to a comprehensive testing device for DC resistance of a transformer and an on-load tap changer, which belongs to the technical field of a comprehensive testing device for a DC resistance of a transformer and an on-load tap changer.

Background technique

The DC resistance test of the transformer winding is an indispensable test item after the transformer is handed over, overhauled, and the tap changer is changed. The on-load tap changer is the only moving part connected to the transformer circuit, so it is necessary to perform The on-load tap-changer is tested. In the "Power Equipment Handover and Preventive Test Regulations", the test items include checking the action sequence of the on-load tap-changer, measuring the switching time, etc.

The traditional test method of the above two test items adopts the split test method, that is, a transformer DC resistance tester and a transformer on-load tap-changer tester are used to connect and test separately, because they are two independent instruments, each The instruments are equipped with special test lines, which require separate tests and separate wiring. Especially when single-phase direct resistance is selected, the wiring mode must be frequently changed. The work of wiring and dismantling will waste a lot of manpower, material resources and working hours, and the conventional direct resistance test When using the two instruments used in the on-load switch test, 3-4 people are required to operate and connect at least twice to test the two parameters respectively, which is time-consuming and labor-intensive.

Utility model content

In order to overcome the deficiencies in the prior art, the utility model needs to solve the technical problem as follows: provide a transformer DC resistance and on-load tap changer comprehensive testing device; in order to solve the above technical problems, the technical solution adopted by the utility model is : A transformer DC resistance and on-load tap changer comprehensive test device, including a box, the front of the box is provided with an LED display screen and control buttons;

One side of the box is provided with a high-voltage test port and a low-voltage test port, and the other side of the box is provided with a power supply module, a data communication module and a constant current source module;

The interior of the box is provided with a control circuit board, the control circuit board is integrated with a central controller, and the central controller is connected to the LED display screen, control buttons, data communication module, and constant current source module through wires;

The power input terminal of the central controller is connected to the power module;

The data communication module is specifically a wireless communication module, and the data communication module is connected to a wireless temperature probe through a wireless network;

The high-voltage test port and the low-voltage test port are respectively serially connected to the AD conversion module and then connected to the central controller;

The central controller is also connected with a data storage module.

The data communication module is also connected with the monitoring terminal.

The circuit structure of the power module is that an AC-to-DC module is arranged inside the power module, the AC input end of the module is sequentially connected with a fuse, and the thermistor is connected with the live wire end of the AC power;

The output terminal of the AC-to-DC module is sequentially connected in parallel with the capacitor C1, the polarized capacitor C2, the voltage stabilizing diode TVS1, and the resistor RL, and then connected with the output terminal of the power module.

The chip used in the constant current source module is the amplifier U1, and the circuit structure of the constant current source module is:

Pin 2 of the amplifier U1 is connected to one end of the capacitor C13 in parallel, and one end of the resistor R13 is connected to one end of the resistor R4; pin 3 of the amplifier U1 is connected to one end of the resistor R5, and the other end of the resistor R5 is connected to the capacitor in parallel. One end of C12 is connected to the power input end;

Pin 6 of the amplifier U1 is connected in parallel with the other end of the capacitor C13, and the other end of the resistor R13 is connected with one end of the resistor R6;

The other end of the resistor R6 is connected in parallel with one end of the capacitor C15 and connected to the gate of the field effect transistor Q1, the source of the field effect transistor Q1 is connected to the 40V input power supply, and the drain of the field effect transistor Q1 is connected in series The resistor R16 is then connected to the output terminal of the constant current source module.

The inside of the constant current source module is also provided with a constant current source gear position control module, and the gear position is controlled through the control button;

The chip used by the constant current source gear control module is a potentiometer U2, and the circuit structure of the constant current source gear control module is:

Pin 1, pin 2, and pin 7 of the potentiometer U2 are respectively connected to the central controller;

The 3 pins of the potentiometer U2 are sequentially connected to the 4 pins of the potentiometer U2, one end of the capacitor C4, the negative pole of the polarized capacitor E2, one end of the capacitor C3, the positive pole of the polarized capacitor E1, and the negative pole of the Zener diode T1 are then grounded ;

The 5th pin of the potentiometer U2 is connected to the negative pole of the diode D1 in parallel and connected to one end of the resistor R2, and the other end of the resistor R2 is connected to the power supply input end;

The 6 pins of the potentiometer U2 are connected in parallel with the other end of the resistor C3, the positive pole of the diode D1, the negative pole of the polarized capacitor E1, and the positive pole of the Zener diode T1 are connected to one end of the resistor R1, and the other end of the resistor R1 is connected to -9V power input terminal;

The 8-pin of the potentiometer U2 is connected in parallel with the other end of the capacitor C4 and then connected with the positive electrode of the polarized capacitor E2.

The front-end circuit of the AD conversion module is provided with a signal conditioning and filtering module, the control chip used by the AD conversion module is an amplifier U3, and the circuit structure of the AD conversion module is:

Pin 2 of the amplifier U3 is connected to one end of the resistor R23 in parallel and then connected to one end of the resistor R24, and the other end of the resistor R23 is grounded;

Pin 3 of the amplifier U3 is connected to one end of the capacitor C65 in parallel and connected to one end of the resistor R8, and the other end of the resistor R8 is connected to the test port;

Pin 4 of the amplifier U3 is connected to one end of the capacitor C34 in parallel, and one end of the capacitor C52 is connected to the -15V input power supply, and the other end of the capacitor C34 is connected to the other end of the capacitor C52 in parallel and grounded;

The pin 6 of the amplifier U3 is connected in parallel with the other end of the resistor R24 and then connected with one end of the resistor R30, and the other end of the resistor R30 is connected in parallel with one end of the capacitor C68 and then connected with the output end of the signal conditioning and filtering module;

Pin 7 of the amplifier U3 is connected in parallel with one end of the capacitor C33, and one end of the capacitor C51 is connected to the 15V input power supply, and the other end of the capacitor C33 is connected in parallel with the other end of the capacitor C51 and grounded.

The chip used by the data storage module is a data storage chip U4, and the circuit structure of the data storage module is:

The 5 pins and 6 pins of the data storage chip U4 are connected to the central controller;

The 8 pins of the data storage chip U4 are connected in parallel to the positive pole of the storage battery BT1 and then connected to one end of the capacitor C30;

The 9 pins of the data storage chip U4 are connected to the other end of the capacitor C30 in parallel, and the negative pole of the storage battery BT1 is grounded;

Pin 10 of the data storage chip U4 is connected to one end of the crystal oscillator X2;

Pin 11 of the data storage chip U4 is connected to the other end of the crystal oscillator X2;

The 12 pins of the data storage chip U4 are connected in series with a resistor R22 and connected to a 3.3V input power supply;

The 13 pins of the data storage chip U4 are connected in series with a resistor R21 and connected to a 3.3V input power supply;

Pin 14 of the data storage chip U4 is connected to a 3.3V input power supply.

The model of the amplifier U1 is OP184; the model of the potentiometer U2 is X9C103; the model of the amplifier U3 is OP1177; the model of the data storage chip U4 is FM31L272.

Compared with the prior art, the utility model has the following beneficial effects: the utility model can complete the DC resistance test of the transformer and the test of the on-load tap changer at the same time through the development of a set of equipment. During the test process of the two inspection items, no Frequent disconnection and connection of test lines is required to improve work efficiency; the test device provided by the utility model integrates multi-functional modules into a box body, has a compact structure, light weight, and strong anti-interference ability, and can complete transformer DC resistance and on-load The test of the tap changer requires only one connection, and the test of the two test items can be quickly and accurately completed by relying on the switching function of the working mode inside the box; the utility model is applied to the conventional test of the current transformer, which can overcome the current test. There are many test points in the work, and the operation of wiring and dismantling is reduced, which fundamentally reduces the labor intensity of the test personnel and shortens the test time.

Description of drawings

Below in conjunction with accompanying drawing, the utility model is further described:

Fig. 1 is the structural representation of the utility model casing;

Fig. 2 is the schematic diagram of the circuit structure of the utility model;

Fig. 3 is the circuit diagram of the utility model power supply module;

Fig. 4 is the circuit diagram of the utility model constant current source module;

Fig. 5 is the circuit diagram of the gear position control module of the constant current source module of the present invention;

Fig. 6 is the circuit diagram of the utility model AD conversion module;

Fig. 7 is the circuit diagram of the utility model data storage module;

In the figure: 1 is the cabinet, 2 is the LED display, 3 is the control button, 4 is the high voltage test port, 5 is the low voltage test port, 6 is the power module, 7 is the data communication module, 8 is the constant current source module, 9 10 is a wireless temperature probe, 11 is an AD conversion module, 12 is a data storage module, and 13 is a monitoring terminal.

Detailed ways

As shown in Figures 1 to 7, the utility model is a transformer DC resistance and on-load tap changer comprehensive testing device, including a box 1, and the front of the box 1 is provided with an LED display 2 and a control button 3;

One side of the box 1 is provided with a high-voltage test port 4 and a low-voltage test port 5, and the other side of the box 1 is provided with a power module 6, a data communication module 7 and a constant current source module 8;

The inside of the box body 1 is provided with a control circuit board, and a central controller 9 is integrated on the control circuit board, and the central controller 9 is respectively connected to the LED display screen 2, the control button 3, the data communication module 7, the 8 constant current source modules are connected;

The power input terminal of the central controller 9 is connected with the power module 6;

The data communication module 7 is specifically a wireless communication module, and the data communication module 7 is connected to the wireless temperature probe 10 through a wireless network;

The high-voltage test port 4 and the low-voltage test port 5 are respectively connected in series with the AD conversion module 11 and then connected to the central controller 9;

The central controller 9 is also connected with a data storage module 12 .

The data communication module 7 is also connected to the monitoring terminal 13 .

The circuit structure of the power module 6 is that the power module 6 is internally provided with an AC-to-DC module, the AC input end of the module is sequentially connected with a fuse, and the thermistor is connected to the live wire end of the AC power;

The output terminal of the AC-to-DC module is sequentially connected to the output terminal of the power module 6 in parallel with the capacitor C1, the polarized capacitor C2, the voltage stabilizing diode TVS1, and the resistor RL.

The chip used in the constant current source module 8 is an amplifier U1, and the circuit structure of the constant current source module 8 is:

Pin 2 of the amplifier U1 is connected to one end of the capacitor C13 in parallel, and one end of the resistor R13 is connected to one end of the resistor R4; pin 3 of the amplifier U1 is connected to one end of the resistor R5, and the other end of the resistor R5 is connected to the capacitor in parallel. One end of C12 is connected to the power input end;

Pin 6 of the amplifier U1 is connected in parallel with the other end of the capacitor C13, and the other end of the resistor R13 is connected with one end of the resistor R6;

The other end of the resistor R6 is connected in parallel with one end of the capacitor C15 and connected to the gate of the field effect transistor Q1, the source of the field effect transistor Q1 is connected to the 40V input power supply, and the drain of the field effect transistor Q1 is connected in series The resistor R16 is then connected to the output terminal of the constant current source module 8 .

The inside of the constant current source module 8 is also provided with a constant current source gear position control module, and the gear position is controlled through the control button 3;

The chip used by the constant current source gear control module is a potentiometer U2, and the circuit structure of the constant current source gear control module is:

Pin 1, pin 2, and pin 7 of the potentiometer U2 are respectively connected to the central controller 9;

The 3 pins of the potentiometer U2 are sequentially connected to the 4 pins of the potentiometer U2, one end of the capacitor C4, the negative pole of the polarized capacitor E2, one end of the capacitor C3, the positive pole of the polarized capacitor E1, and the negative pole of the Zener diode T1 are then grounded ;

The 5th pin of the potentiometer U2 is connected to the negative pole of the diode D1 in parallel and connected to one end of the resistor R2, and the other end of the resistor R2 is connected to the power supply input end;

The 6 pins of the potentiometer U2 are connected in parallel with the other end of the resistor C3, the positive pole of the diode D1, the negative pole of the polarized capacitor E1, and the positive pole of the Zener diode T1 are connected to one end of the resistor R1, and the other end of the resistor R1 is connected to -9V power input terminal;

The 8-pin of the potentiometer U2 is connected in parallel with the other end of the capacitor C4 and then connected with the positive electrode of the polarized capacitor E2.

The front-end circuit of the AD conversion module 11 is provided with a signal conditioning and filtering module, and the control chip used by the AD conversion module 11 is an amplifier U3, and the circuit structure of the AD conversion module 11 is:

Pin 2 of the amplifier U3 is connected to one end of the resistor R23 in parallel and then connected to one end of the resistor R24, and the other end of the resistor R23 is grounded;

Pin 3 of the amplifier U3 is connected to one end of the capacitor C65 in parallel and connected to one end of the resistor R8, and the other end of the resistor R8 is connected to the test port;

Pin 4 of the amplifier U3 is connected to one end of the capacitor C34 in parallel, and one end of the capacitor C52 is connected to the -15V input power supply, and the other end of the capacitor C34 is connected to the other end of the capacitor C52 in parallel and grounded;

The pin 6 of the amplifier U3 is connected in parallel with the other end of the resistor R24 and then connected with one end of the resistor R30, and the other end of the resistor R30 is connected in parallel with one end of the capacitor C68 and then connected with the output end of the signal conditioning and filtering module;

Pin 7 of the amplifier U3 is connected in parallel with one end of the capacitor C33, and one end of the capacitor C51 is connected to the 15V input power supply, and the other end of the capacitor C33 is connected in parallel with the other end of the capacitor C51 and grounded.

The chip used by the data storage module 12 is a data storage chip U4, and the circuit structure of the data storage module 12 is:

The 5 pins and 6 pins of the data storage chip U4 are connected to the central controller 9;

The 8 pins of the data storage chip U4 are connected in parallel to the positive pole of the storage battery BT1 and then connected to one end of the capacitor C30;

The 9 pins of the data storage chip U4 are connected to the other end of the capacitor C30 in parallel, and the negative pole of the storage battery BT1 is grounded;

Pin 10 of the data storage chip U4 is connected to one end of the crystal oscillator X2;

Pin 11 of the data storage chip U4 is connected to the other end of the crystal oscillator X2;

The 12 pins of the data storage chip U4 are connected in series with a resistor R22 and connected to a 3.3V input power supply;

The 13 pins of the data storage chip U4 are connected in series with a resistor R21 and connected to a 3.3V input power supply;

Pin 14 of the data storage chip U4 is connected to a 3.3V input power supply.

The model of the amplifier U1 is OP184; the model of the potentiometer U2 is X9C103; the model of the amplifier U3 is OP1177; the model of the data storage chip U4 is FM31L272.

In the design of the utility model, both the DC resistance test and the DC method OLTC test are output constant current sources, and there are common points in the wiring, that is, the A/B/C/O ports of the high-voltage side are connected at the same time All are connected to the instrument (the direct resistance test adopts the three-channel simultaneous measurement method, so all the phases need to be connected to the instrument), so the two test instruments can be combined into one instrument for use. During the design process, it is necessary Accurately calculate the parameters of the components, rationally configure the components, design the sampling processing units required for the two tests, and integrate and install each unit module to complete the production.

The box body 1 designed by the utility model adopts an all-aluminum alloy structure, the control button 3 is specifically a structure combining an embedded button and a shuttle knob, and the signal output panel adopts the same terminal row; The two parameters of resistance and on-load tap-changer should also introduce the concept of "one-key measurement" in the test of direct resistance, that is, the instrument can automatically complete the resistance values of all windings of high and low voltage transformers after setting the parameters, which can further reduce the test time; During the test, it can also establish a connection with the wireless temperature probe to realize real-time measurement and reference of the transformer temperature.

The utility model designs a test instrument that integrates two functions. The metal structure of the box body can achieve the effect of anti-interference. The design of the knob is helpful for analyzing the waveform during the load test. One-key measurement can save a lot of time. Wireless temperature measurement The temperature data can be monitored in real time to meet the measurement accuracy and anti-interference ability requirements of the test device.

The power supply module 6 designed by the utility model has effective filtering and protection design for the input and output terminals of the power supply, which reduces the ripple and noise interference of the power supply system, and can ensure a clean and stable power supply output for the entire test system .

The constant current source module 8 can provide a stable constant current source for the DC resistance test and the on-load test. The utility model optimizes the design of the constant current source. On the basis of ensuring the stability of the constant current source, low noise and high precision , improve the response speed and stability, and ensure that the data obtained by the two tests are accurate and fast.

The sampling system requires the central controller 9 to efficiently and stably process the collected data. This utility model adopts a synchronous sampling chip of the model AD7606, which has 16 bits and 8 channels, and collects data from the measurement results to ensure the stability and reliability of data measurement. , Efficiency.

The external wireless temperature probe 10 of the utility model uses a model of DS18B20 temperature sensor chip. The chip is waterproof and moisture-proof and is packaged by a stainless steel tube. It is easy to install and use, and uses a wireless communication module to transmit the monitored temperature data to the test instrument in real time.

The data storage module 12 uses a large-capacity ferroelectric memory chip FM31L272 inside to ensure real-time storage of measurement data. The chip has a watchdog circuit to ensure the reliability of the overall operation of the instrument.

The technical parameters of the DC resistance test and on-load tap changer parameter testing device provided by the utility model are as follows:

The required parameters of DC resistance measurement test current are: three-phase test: 5A+5A, 1A+1A, two levels are optional; split-phase test: 10A, 5A, 1A, three levels are optional;

Test Range:

10A: 1.000mΩ~1Ω;

5A: 10.00mΩ~4Ω, 5A+5A, 10mΩ~1Ω;

1A: 100.0mΩ~20Ω, 1A+1A, 100mΩ~5Ω;

Minimum resolution: 0.1uΩ

Accuracy: ± (0.2%+2 characters)

The test parameters of the on-load tap-changer are: output current: 1.0A, 0.5A, 0.3A, three options;

Resistance range: 0.1~10Ω at 1.0A; 5~20Ω at 0.5A; 10~40Ω at 0.3A;

Resistance measurement accuracy: ±(reading×5%+5 characters), resolution: 0.01Ω;

Transition time measurement range: 1 ~ 250mS;

Transition time measurement accuracy: ±1mS, resolution: 0.1mS;

The sampling frequency is 10KHz.

The test system realizes two parts of the test function by installing and setting the signal processing acquisition and processing module, the stable constant current source module, the multi-function switching module, and the high-precision AD sampling module; among them, the high stable constant current source circuit can generate Three-way constant current source for on-load tap-changer testing; the multi-function switching circuit can switch between different signal sampling (direct-resistance slow-speed sampling and on-load high-speed sampling); the high-precision AD sampling module converts analog signals into digital signals through 32 The central processing unit is used for processing, so as to calculate the required test parameters; the utility model adopts an integrated structure design, and when carrying out the test of two test items, it only needs to connect the test line at one time, and then through human-computer interaction Module selection to carry out the corresponding test items, you can complete the test of all items.

Example:

Use the utility model to test the existing substation, and the test data are as follows:

On November 12, 2018, the test was carried out at No. 2 main transformer of a 110kV substation. The parameters of the transformer are:

Model: SSZ11-50000/110;

Rated voltage: (110±8X1.25%)/38.5±2X2.5%/10.5kV;

Rated capacity: 50000kVA;

Factory number: 201509-0005;

Date of manufacture: 2015.12;

The field test status is as follows:

Time: November 12, 2018;

Location: a 110kV substation;

Equipment: transformer;

Equipment model: SSZ11-50000/110;

Equipment status: power failure;

Test conditions: first use the DC resistance tester and the on-load tap-changer tester to test the transformer and switch respectively, and then use the direct resistance plus on-load two-in-one instrument developed by the utility model to test, the test conditions are as follows:

The test times are as follows:

Direct resistance tester 35 minutes and 10 seconds;

On-load tap-changer tester for 25 minutes and 50 seconds;

40 minutes and 33 seconds for direct resistance plus on-load two-in-one device;

Conclusion: the measurement result of the device of the utility model is accurate, and the two parts of the test experiment are combined into one part, which saves a lot of time.

In the above transformer direct resistance and on-load switch tests, the test personnel were reduced from 3-4 to 2, and the test time was reduced from 61 minutes and 00 seconds to 40 minutes and 33 seconds.

Therefore, it can be concluded that using the test device of the utility model to replace the traditional direct resistance test device and on-load switch test device can effectively improve the accuracy of the detection results and reduce the measurement time.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present utility model, and are not intended to limit it; although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand : It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements to some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the various embodiments of the present invention Scope of technical solutions.

Claims (8)

1. A transformer DC resistance and on-load tap-changer comprehensive test device, characterized in that: it includes a box (1), the front of the box (1) is provided with an LED display (2), control buttons (3 ); One side of the box (1) is provided with a high-voltage test port (4) and a low-voltage test port (5), and the other side of the box (1) is provided with a power module (6), a data communication module (7) and Constant current source module (8); The inside of the box (1) is provided with a control circuit board, and a central controller (9) is integrated on the control circuit board, and the central controller (9) is respectively connected to the LED display (2), the control The button (3), the data communication module (7), and the constant current source module (8) are connected; The power input terminal of the central controller (9) is connected to the power module (6); The data communication module (7) is specifically a wireless communication module, and the data communication module (7) is connected to the wireless temperature probe (10) through a wireless network; The high-voltage test port (4) and the low-voltage test port (5) are respectively connected in series with the AD conversion module (11) and then connected to the central controller (9); The central controller (9) is also connected with a data storage module (12). 2. A transformer DC resistance and on-load tap changer comprehensive testing device according to claim 1, characterized in that: the data communication module (7) is also connected to the monitoring terminal (13). 3. A transformer DC resistance and on-load tap-changer comprehensive testing device according to claim 2, characterized in that: the circuit structure of the power module (6) is that the power module (6) is internally equipped with AC to DC module, the AC input end of the module is connected in series with fuses, and the thermistor is connected to the live wire end of the AC power; The output terminal of the AC-to-DC module is sequentially connected in parallel with a capacitor C1, a polarized capacitor C2, a voltage stabilizing diode TVS1, and a resistor RL, and then connected to the output terminal of the power supply module (6). 4. A transformer DC resistance and on-load tap-changer comprehensive test device according to claim 3, characterized in that: the chip used in the constant current source module (8) is an amplifier U1, and the constant current source module (8) The circuit structure is: Pin 2 of the amplifier U1 is connected to one end of the capacitor C13 in parallel, and one end of the resistor R13 is connected to one end of the resistor R4; pin 3 of the amplifier U1 is connected to one end of the resistor R5, and the other end of the resistor R5 is connected to the capacitor in parallel. One end of C12 is connected to the power input end; Pin 6 of the amplifier U1 is connected in parallel with the other end of the capacitor C13, and the other end of the resistor R13 is connected with one end of the resistor R6; The other end of the resistor R6 is connected in parallel with one end of the capacitor C15 and connected to the gate of the field effect transistor Q1, the source of the field effect transistor Q1 is connected to the 40V input power supply, and the drain of the field effect transistor Q1 is connected in series The resistor R16 is connected to the output terminal of the constant current source module (8). 5. A transformer DC resistance and on-load tap-changer comprehensive test device according to claim 4, characterized in that: the constant current source module (8) is also provided with a constant current source gear control module inside, and The gear position is controlled by the control button (3); The chip used by the constant current source gear control module is a potentiometer U2, and the circuit structure of the constant current source gear control module is: Pin 1, pin 2, and pin 7 of the potentiometer U2 are respectively connected to the central controller (9); The 3 pins of the potentiometer U2 are sequentially connected to the 4 pins of the potentiometer U2, one end of the capacitor C4, the negative pole of the polarized capacitor E2, one end of the capacitor C3, the positive pole of the polarized capacitor E1, and the negative pole of the Zener diode T1 are then grounded ; The 5th pin of the potentiometer U2 is connected to the negative pole of the diode D1 in parallel and connected to one end of the resistor R2, and the other end of the resistor R2 is connected to the power supply input end; The 6 pins of the potentiometer U2 are connected in parallel with the other end of the resistor C3, the positive pole of the diode D1, the negative pole of the polarized capacitor E1, and the positive pole of the Zener diode T1 are connected to one end of the resistor R1, and the other end of the resistor R1 is connected to -9V power input terminal; The 8-pin of the potentiometer U2 is connected in parallel with the other end of the capacitor C4 and then connected with the positive electrode of the polarized capacitor E2. 6. A transformer DC resistance and on-load tap-changer comprehensive test device according to claim 5, characterized in that: the front-end circuit of the AD conversion module (11) is provided with a signal conditioning and filtering module, the AD The control chip used by the conversion module (11) is an amplifier U3, and the circuit structure of the AD conversion module (11) is: Pin 2 of the amplifier U3 is connected to one end of the resistor R23 in parallel and then connected to one end of the resistor R24, and the other end of the resistor R23 is grounded; Pin 3 of the amplifier U3 is connected to one end of the capacitor C65 in parallel and connected to one end of the resistor R8, and the other end of the resistor R8 is connected to the test port; Pin 4 of the amplifier U3 is connected to one end of the capacitor C34 in parallel, and one end of the capacitor C52 is connected to the -15V input power supply, and the other end of the capacitor C34 is connected to the other end of the capacitor C52 in parallel and grounded; The pin 6 of the amplifier U3 is connected in parallel with the other end of the resistor R24 and then connected with one end of the resistor R30, and the other end of the resistor R30 is connected in parallel with one end of the capacitor C68 and then connected with the output end of the signal conditioning and filtering module; Pin 7 of the amplifier U3 is connected in parallel with one end of the capacitor C33, and one end of the capacitor C51 is connected to the 15V input power supply, and the other end of the capacitor C33 is connected in parallel with the other end of the capacitor C51 and grounded. 7. A transformer DC resistance and on-load tap changer comprehensive test device according to claim 6, characterized in that: the chip used by the data storage module (12) is a data storage chip U4, and the data storage module (12) The circuit structure is: Pins 5 and 6 of the data storage chip U4 are connected to the central controller (9); The 8 pins of the data storage chip U4 are connected in parallel to the positive pole of the storage battery BT1 and then connected to one end of the capacitor C30; The 9 pins of the data storage chip U4 are connected to the other end of the capacitor C30 in parallel, and the negative pole of the storage battery BT1 is grounded; Pin 10 of the data storage chip U4 is connected to one end of the crystal oscillator X2; Pin 11 of the data storage chip U4 is connected to the other end of the crystal oscillator X2; The 12 pins of the data storage chip U4 are connected in series with a resistor R22 and connected to a 3.3V input power supply; The 13 pins of the data storage chip U4 are connected in series with a resistor R21 and connected to a 3.3V input power supply; Pin 14 of the data storage chip U4 is connected to a 3.3V input power supply. 8. A kind of transformer DC resistance and on-load tap changer comprehensive testing device according to claim 7, is characterized in that: the model of described amplifier U1 is OP184; The model of potentiometer U2 is X9C103; The model of amplifier U3 is OP1177; the model of the data storage chip U4 is FM31L272.