Multipath insulation resistance measuring device

By incorporating a relay control module, a microcontroller, a power supply module, a communication module, an AD conversion module, a high-voltage sampling module, and a multi-channel measurement module, the problems of low efficiency and inconvenient data management in traditional insulation resistance measurement devices are solved, enabling synchronous measurement and data storage of multiple insulation resistances.

CN223711710UActive Publication Date: 2025-12-23SHIJIAZHUANG POWER SUPPLY SECTION OF CHINA RAILWAY BEIJING BUREAU GRP CO LTD +1
View PDF 0 Cites 0 Cited by

Patent Information

Application Number
CN202422888913.3
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-11-26
Publication Date
2025-12-23
Estimated Expiration
2034-11-26

AI Technical Summary

Technical Problem

Traditional insulation resistance measuring devices can only measure one section of insulation rod at a time, resulting in low efficiency from repeated operations. Furthermore, they cannot store data or transmit it to a computer, making it difficult to meet the needs of efficient management of multiple insulation rod sections.

Method used

Design a multi-channel insulation resistance measuring device, comprising a relay control module, a microcontroller, a power supply module, a communication module, an AD conversion module, a high-voltage sampling module, and a multi-channel measurement module, to achieve simultaneous multi-channel measurement, and store and transmit data through the communication module.

Benefits of technology

It enables simultaneous measurement of insulation resistance across multiple channels, improving the work efficiency of testing personnel and simplifying data storage and management.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN223711710U_ABST
    Figure CN223711710U_ABST
Patent Text Reader

Abstract

The utility model belongs to the technical field of resistance measurement, and particularly discloses a multipath insulation resistance measuring device which comprises a shell and a multipath acquisition circuit board, on the multipath acquisition circuit board, a single-chip microcomputer is in communication connection with an external upper computer through a communication module, the single-chip microcomputer is respectively and electrically connected with a relay control module and an AD conversion module, and the relay control module is electrically connected with the AD conversion module. The AD conversion module is electrically connected with the high-voltage sampling module and the multi-path measurement module respectively, and the power supply module supplies power to the modules; a power interface, a communication interface and a plurality of groups of wiring terminals are arranged on the shell, the multi-path measurement module is connected with a plurality of groups of external special test electrodes through the plurality of groups of wiring terminals, the multi-path measurement module, the plurality of groups of wiring terminals and the plurality of groups of special test electrodes are in one-to-one correspondence, and the power module is connected with an external power supply through the power interface. The communication module is connected with an external upper computer through a communication interface. The multi-channel insulation resistance measuring device can measure multi-channel insulation resistance at the same time and store measured data, thereby improving work efficiency. The multi-channel insulation resistance measuring device is suitable for measuring multi-channel insulation resistance.
Need to check novelty before this filing date? Find Prior Art

Description

TECHNICAL FIELD

[0001] The utility model belongs to resistance measurement technical field, concretely is a kind of multiway insulation resistance measuring device. BACKGROUND

[0002] Insulation resistance is the most basic insulation index of electrical equipment and electrical circuit, and insulation rod is a safety tool used in power system, which can effectively prevent the electric shock of operator. In order to ensure safety and reliability, it is required to detect the insulation resistance of the insulation rod. The traditional insulation resistance measurement method is to contact the detected insulation rod to detect the resistance value through the internal electrode device of the portable insulation rod insulation resistance tester. The insulation resistance of a single insulation rod can be tested at a time. For the measurement of insulation resistance of multiple insulation rods, wiring and measurement operations need to be repeated multiple times, which is low in work efficiency. Moreover, the portable insulation rod insulation resistance tester can only display the current test value, cannot store data, and cannot be transmitted to the computer to be saved in the form of document, which is not convenient for the management of subsequent insulation rod insulation resistance test. SUMMARY

[0003] The utility model aims at providing a kind of multiway insulation resistance measuring device, can measure multiple insulation resistances simultaneously, and store measurement data, to improve work efficiency.

[0004] In order to achieve the above-mentioned purpose, the technical method adopted by the utility model is as follows:

[0005] A kind of multiway insulation resistance measuring device, comprising a shell, and a plurality of acquisition circuit boards installed in the shell, a plurality of acquisition circuit boards are provided with a relay control module, a single-chip microcomputer, a power module, a communication module, an AD conversion module, a high-voltage sampling module and a plurality of measurement modules, the single-chip microcomputer is connected with external host computer in communication by the communication module, the single-chip microcomputer is electrically connected with the relay control module and the AD conversion module respectively, the AD conversion module is electrically connected with the high-voltage sampling module and the plurality of measurement modules respectively, and the power module supplies power for the relay control module, the single-chip microcomputer, the communication module, the AD conversion module, the high-voltage sampling module and the plurality of measurement modules;The shell is provided with a power interface, a communication interface and a plurality of groups of terminal blocks, the plurality of measurement modules are connected with external multiple groups of special test electrodes through the plurality of groups of terminal blocks, the plurality of measurement modules, the plurality of groups of terminal blocks and the multiple groups of special test electrodes are one-to-one correspondence, the power module is connected with external power supply through the power interface, and the communication module is connected with external host computer through the communication interface.

[0006] As a limitation: the power module includes an AC / DC conversion element and an isolation element, the model of the AC / DC conversion element is LS15-23B05DR3, the model of the isolation element is A0509S-2WR2, the input pin of the AC / DC conversion element is connected with an external power supply, the output pin of the AC / DC conversion element outputs a first voltage, the input pin of the isolation element inputs a second voltage, the output pin of the isolation element outputs the second voltage and a third voltage, a first capacitor is connected between the first voltage and the ground, a second capacitor and a third capacitor are respectively connected between the second voltage and the third voltage and the ground.

[0007] As a limitation: the AD conversion module includes at least two AD converters and at least two reference voltage elements, the AD converter and the reference voltage element are one-to-one corresponding, the clock pin, the chip select pin, the serial data input pin and the serial data output pin of each AD converter are connected with a single-chip microcomputer, the main clock input pin and the main clock output pin of each AD converter are connected with a first crystal oscillator, one end of the first crystal oscillator is connected with one end of a fifth capacitor, the other end of the fifth capacitor is grounded, the other end of the first crystal oscillator is connected with one end of a sixth capacitor, the other end of the sixth capacitor is grounded; the reset pin of each AD converter is connected with one end of a second resistor, the other end of the second resistor is connected with a first voltage; the voltage pin of each AD converter is connected with the first voltage, and a seventh capacitor is connected between the first voltage and the ground; the reference input pin of each AD converter is connected with the anode pin of one reference voltage element, the anode pin of the reference voltage element is connected with the first voltage through a third resistor, and the cathode pin of the reference voltage element is grounded; the reference input pins of all AD converters are connected, and the analog signal input ends of all AD converters are connected with a multi-channel measurement module, and the analog signal input end of one AD converter is further connected with a high-voltage sampling module.

[0008] As a limitation: the relay control module includes a first relay element, the common end of the first relay element is connected with a first voltage, one end of the coil of the first relay element is connected with the first voltage, the other end of the coil of the first relay element is connected with the collector of a first transistor, the emitter of the first transistor is grounded, the base of the first transistor is connected with one end of a fourth resistor, the other end of the fourth resistor is respectively connected with one end of a fifth resistor and a single-chip microcomputer, the current monitoring pin of the first relay element is connected with the single-chip microcomputer, and the reference voltage pin and the adjustment pin of the first relay element are connected.

[0009] As a limitation: the high-voltage sampling module includes a first operational amplifier, the voltage pin of the first operational amplifier is connected with the second voltage and the third voltage, the positive input pin of the first operational amplifier is connected with one end of the ninth capacitor and one end of the eighth resistor respectively, the other end of the ninth capacitor is grounded, the other end of the eighth resistor is connected with one end of the ninth resistor and one end of the tenth resistor respectively, the other end of the ninth resistor is grounded, the other end of the tenth resistor is connected with one end of the eleventh resistor, the other end of the eleventh resistor is connected with one end of the twelfth resistor, the other end of the twelfth resistor is connected with one end of the thirteenth resistor, the other end of the thirteenth resistor is connected with one end of the fourteenth resistor, the other end of the fourteenth resistor is connected with the high voltage through the high-voltage terminal; the output pin of the first operational amplifier is connected with one end of the first diode and one end of the seventh resistor respectively, the other end of the first diode is connected with one end of the eighth capacitor, one end of the sixth resistor and the ground respectively, the other end of the sixth resistor is connected with the other end of the seventh resistor, the other end of the eighth capacitor and the AD conversion module respectively.

[0010] As a limitation: each group of terminals includes a high-voltage terminal and a low-voltage terminal, the high-voltage terminal is connected with the test positive electrode, and the low-voltage terminal is connected with the test negative electrode; the measurement circuit of each channel in the multi-channel measurement module includes a second operational amplifier and a second relay element, the voltage pin of the second operational amplifier is connected with the second voltage and the third voltage, the positive input pin of the second operational amplifier is connected with one end of the eleventh capacitor and one end of the seventeenth resistor respectively, the other end of the eleventh capacitor is grounded, the other end of the seventeenth resistor is connected with one end of the eighteenth resistor, the test positive electrode and one end of the inductor respectively, the other end of the inductor is connected with one end of the twelfth capacitor, the other end of the twelfth capacitor is connected with the test negative electrode and one end of the twenty-first resistor of the inductor respectively, the other end of the twenty-first resistor is connected with the high voltage; the other end of the eighteenth resistor is connected with one end of the nineteenth resistor and the normally open end of the second relay element respectively, the other end of the nineteenth resistor is connected with the common end of the second relay element, the normally closed end of the second relay element and the ground respectively, the voltage pin of the second relay element is connected with the first voltage, and the third diode is connected between the negative pin and the positive pin of the second relay element, the collector of the second transistor is also connected with the negative pin of the second relay element, the emitter of the second transistor is grounded, and the base of the second transistor is connected with one end of the twentieth resistor and the single-chip microcomputer respectively, the other end of the twentieth resistor is grounded; the output pin of the second operational amplifier is connected with one end of the second diode and one end of the sixteenth resistor respectively, the other end of the second diode is connected with one end of the tenth capacitor, one end of the fifteenth resistor and the ground respectively, the other end of the fifteenth resistor is connected with the other end of the sixteenth resistor, the other end of the tenth capacitor and the AD conversion module respectively.

[0011] As a limitation: the communication module includes an isolated transceiver and a communication serial port. The isolated transceiver is model TD501D485H, and the communication serial port is an RS232 serial port. The differential signal input pin of the isolated transceiver is connected to the RS485 communication line. The signal transmit pin, signal receive pin, and control pin of the isolated transceiver, as well as the signal transmit pin and signal receive pin of the RS232 serial port, are all connected to the microcontroller. The voltage pin of the isolated transceiver is connected to the first voltage. The voltage pin of the RS232 serial port is connected to the first voltage and one end of the fourth capacitor, respectively. The other end of the fourth capacitor is connected to one end of the first resistor and the microcontroller, respectively. The other end of the first resistor is grounded.

[0012] As a limitation, the microcontroller model is STC12C5A60S2 LQFP44.

[0013] The beneficial effects achieved by this utility model, due to the adoption of the above-mentioned solution, compared with the prior art, are as follows:

[0014] This utility model provides a multi-channel insulation resistance measuring device. By setting up a relay control module, a microcontroller, a power supply module, a communication module, an AD conversion module, a high-voltage sampling module, and a multi-channel measurement module, it can simultaneously measure the insulation resistance of multiple insulation rods or even a group of insulation rods, thus improving the work efficiency of test personnel. The power supply module is powered by an external AC220V supply, which can meet the needs of long-term test work. The communication module communicates via RS485 serial port, which facilitates the subsequent storage and comparative analysis of insulation resistance test data of the insulation rods by the host computer, thus facilitating the management of insulation resistance tests of the insulation rods.

[0015] This invention is applicable to the measurement of multi-channel insulation resistance. Attached Figure Description

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0017] Figure 1 This is a structural block diagram of a multi-channel insulation resistance measuring device according to an embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of the microcontroller in an embodiment of the present utility model;

[0019] Figure 3 This is a circuit diagram of the power module according to an embodiment of the present invention;

[0020] Figure 4 This is a circuit diagram of the AD conversion module according to an embodiment of the present invention;

[0021] Figure 5 This is a circuit diagram of the relay control module according to an embodiment of the present invention;

[0022] Figure 6 This is a circuit diagram of the high-voltage sampling module according to an embodiment of the present invention;

[0023] Figure 7 This is a circuit diagram of one measurement circuit in the multi-channel measurement module of this utility model embodiment;

[0024] Figure 8 This is a circuit diagram of the communication module in an embodiment of the present invention. Detailed Implementation

[0025] The present invention will be further described below with reference to the embodiments. However, those skilled in the art should understand that the present invention is not limited to the following embodiments. Any improvements and equivalent changes made based on the specific embodiments of the present invention are within the scope of protection of the claims of the present invention.

[0026] Example 1: A multi-channel insulation resistance measuring device

[0027] A multi-channel insulation resistance measuring device includes a housing and a multi-channel acquisition circuit board installed inside the housing. The housing is mounted on a bracket of the testing system and is a waterproof and insulating housing. Figure 1 As shown, the multi-channel acquisition circuit board includes a relay control module, a microcontroller, a power supply module, a communication module, an AD conversion module, a high-voltage sampling module, and a multi-channel measurement module, such as... Figure 2 As shown, the microcontroller model is STC12C5A60S2 LQFP44. The microcontroller communicates with an external host computer via a communication module. The microcontroller is electrically connected to the relay control module and the AD conversion module. The AD conversion module is electrically connected to the high-voltage sampling module and the multi-channel measurement module. The power supply module supplies power to the relay control module, microcontroller, communication module, AD conversion module, high-voltage sampling module, and multi-channel measurement module. The housing is equipped with a DB9 interface and multiple sets of terminal blocks. The multi-channel measurement module is connected to multiple sets of external dedicated test electrodes via multiple sets of terminal blocks. The multi-channel measurement module, multiple sets of terminal blocks, and multiple sets of dedicated test electrodes correspond one-to-one. The power supply module is connected to an external power supply via the DB9 interface, and the communication module is connected to an external host computer via the DB9 interface.

[0028] like Figure 3As shown in the figure, the power module includes an AC / DC conversion element and an isolation element, the model of the AC / DC conversion element is LS15-23B05DR3, the model of the isolation element is A0509S-2WR2, the input pin of the AC / DC conversion element is connected with an external power supply, the output pin of the AC / DC conversion element outputs a first voltage 5V, the input pin of the isolation element inputs a second voltage 9V, the output pin of the isolation element outputs the second voltage 9V and a third voltage -9V, the first voltage 5V and the ground are connected with a first capacitor C1, the second voltage 9V and the third voltage -9V are respectively connected with a second capacitor C2 and a third capacitor C3.

[0029] As shown in the figure, Figure 4 As shown in the figure, the AD conversion module includes at least two AD converters and at least two reference voltage elements, the AD converters and the reference voltage elements are one-to-one corresponding, the clock pin, the chip select pin, the serial data input pin and the serial data output pin of each AD converter are connected with the single-chip microcomputer, the main clock input pin and the main clock output pin of each AD converter are connected with a first crystal oscillator Y1, one end of the first crystal oscillator Y1 is connected with one end of a fifth capacitor C5, the other end of the fifth capacitor C5 is grounded, the other end of the first crystal oscillator Y1 is connected with one end of a sixth capacitor C6, the other end of the sixth capacitor C6 is grounded; the reset pin of each AD converter is connected with one end of a second resistor R2, the other end of the second resistor R2 is connected with the first voltage 5V; the voltage pin of each AD converter is connected with the first voltage 5V, the first voltage 5V and the ground are connected with a seventh capacitor C7; the reference input pin of each AD converter is connected with the anode pin of one reference voltage element, the anode pin of the reference voltage element is connected with the first voltage 5V through a third resistor R3, the cathode pin of the reference voltage element is grounded; the reference input pins of all the AD converters are connected, the analog signal input ends of all the AD converters are connected with the multi-channel measurement module, and the analog signal input end of one of the AD converters is also connected with the high-voltage sampling module. The embodiment includes two AD converters and two reference voltage elements, the models of the two AD converters are AD7705 and AD7706 respectively, and the model of the reference voltage element is LM285-2.5.

[0030] As shown in the figure, Figure 5As shown, the relay control module includes a first relay element, the model of the first relay element is JQZ-32F5-Z, the common terminal of the first relay element is connected with the first voltage 5V, one end of the coil K0 of the first relay element is connected with the first voltage 5V, the other end of the coil K0 of the first relay element is connected with the collector of the first transistor Q1, the emitter of the first transistor Q1 is grounded, the base of the first transistor Q1 is connected with one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected with one end of the fifth resistor R5 and the single-chip microcomputer respectively, the current monitoring pin of the first relay element is connected with the single-chip microcomputer, and the reference voltage pin of the first relay element is connected with the adjusting pin thereof.

[0031] As shown in the figure, Figure 6 As shown, the high-voltage sampling module includes a first operational amplifier, the model of the first operational amplifier is OP07, the voltage pin of the first operational amplifier is connected with the second voltage 9V and the third voltage-9V, the positive input pin of the first operational amplifier is connected with one end of the ninth capacitor C9 and one end of the eighth resistor R8 respectively, the other end of the ninth capacitor C9 is grounded, the other end of the eighth resistor R8 is connected with one end of the ninth resistor R9 and one end of the tenth resistor R10 respectively, the other end of the ninth resistor R9 is grounded, the other end of the tenth resistor R10 is connected with one end of the eleventh resistor R11, the other end of the eleventh resistor R11 is connected with one end of the twelfth resistor R12, the other end of the twelfth resistor R12 is connected with one end of the thirteenth resistor R13, the other end of the thirteenth resistor R13 is connected with one end of the fourteenth resistor R14, the other end of the fourteenth resistor R14 is connected with the high voltage HV through the HV terminal; the output pin of the first operational amplifier is connected with one end of the first diode D1 and one end of the seventh resistor R7 respectively, the other end of the first diode D1 is connected with one end of the eighth capacitor C8, one end of the sixth resistor R6 and the ground respectively, the other end of the sixth resistor R6 is connected with the other end of the seventh resistor R7, the other end of the eighth capacitor C8 and the AD conversion module respectively.

[0032] Each set of terminal includes a high-voltage terminal and a low-voltage terminal, the high-voltage terminal is connected with the test positive electrode, and the low-voltage terminal is connected with the test negative electrode; the measurement circuit of each channel in the multi-channel measurement module includes a second operational amplifier and a second relay element, the model of the second operational amplifier is OP07, and the model of the second relay element is TQ2-5V, and the embodiment is a four-channel measurement circuit, one set of terminals includes an L1 high-voltage terminal and an E1 low-voltage terminal, and a corresponding channel measurement circuit is as shown in the figure, Figure 7As shown, the voltage pin of the second operational amplifier is connected with the second voltage 9V and the third voltage -9V, the positive input pin of the second operational amplifier is connected with one end of the eleventh capacitor C11 and one end of the seventeenth resistor R17 respectively, the other end of the eleventh capacitor C11 is grounded, the other end of the seventeenth resistor R17 is connected with one end of the eighteenth resistor R18, the test positive electrode L1 and one end of the inductor L respectively, the other end of the inductor L is connected with one end of the twelfth capacitor C12, the other end of the twelfth capacitor C12 is connected with the test negative electrode E1 and one end of the twenty-first resistor R21 of the inductor L respectively, the other end of the twenty-first resistor R21 is connected with the high voltage HV; the other end of the eighteenth resistor R18 is connected with one end of the nineteenth resistor R19 and the normally open end of the second relay element respectively, the other end of the nineteenth resistor R19 is connected with the common end of the second relay element, the normally closed end of the second relay element and the ground respectively, the voltage pin of the second relay element is connected with the first voltage 5V and the third diode D3 is connected between the negative pin and the positive pin of the second relay element, the negative pin of the second relay element is also connected with the collector of the second transistor Q2, the emitter of the second transistor Q2 is grounded, the base of the second transistor Q2 is connected with one end of the twentieth resistor R20 and the single-chip microcomputer respectively, the other end of the twentieth resistor R20 is grounded; the output pin of the second operational amplifier is connected with one end of the second diode D2 and one end of the sixteenth resistor R16 respectively, the other end of the second diode D2 is connected with one end of the tenth capacitor C10, one end of the fifteenth resistor R15 and the ground respectively, the other end of the fifteenth resistor R15 is connected with the other end of the sixteenth resistor R16, the other end of the tenth capacitor C10 and the AD conversion module respectively.

[0033] As shown in the figure, Figure 8 As shown, the communication module includes an isolation transceiver and a communication serial port, the model of the isolation transceiver is TD501D485H, the communication serial port is an RS232 serial port, the differential signal input pin of the isolation transceiver is connected with the RS485 communication line, the signal sending pin, the signal receiving pin and the control pin of the isolation transceiver, and the signal sending pin and the signal receiving pin of the RS232 serial port are all connected with the single-chip microcomputer, the voltage pin of the isolation transceiver is connected with the first voltage 5V, the voltage pin of the RS232 serial port is connected with the first voltage 5V and one end of the fourth capacitor C4 respectively, the other end of the fourth capacitor C4 is connected with one end of the first resistor R1 and the single-chip microcomputer respectively, the other end of the first resistor R1 is grounded.

[0034] The use process of the multi-channel insulation resistance measuring device of the embodiment is as follows: first, the power supply line and the communication line are connected with the DB9 interface, after the power supply is turned on, the AC 220V voltage is stepped down and stabilized by the power supply module to obtain the DC 5V voltage, which is used to power the multi-channel insulation resistance measuring device, after the single-chip microcomputer is sent the start test instruction through the RS485 communication line, the relay control module controls the start of the high-voltage test, the high-voltage signal is sent to the single-chip microcomputer after being processed by the high-voltage sampling module and the AD converter, and the 2500V digital signal is converted, then the multi-channel measuring module processes four insulation resistance test signals at the same time, the resistance value digital signal is obtained after being processed by the AD conversion module, and the digital signal is sent to the single-chip microcomputer, the single-chip microcomputer processes the high-voltage digital signal and the four resistance digital signals, and sends them to the external host computer through the communication module, after the single-chip microcomputer is sent the end test instruction by the host computer through the communication module, the first relay element in the relay control module cuts off the high-voltage output, and the test is completed.

Claims

1. A multipath insulation resistance measuring device, characterized by, The shell is provided with a power supply interface, a communication interface and a plurality of groups of wiring terminals, the multi-channel measurement module is connected with a plurality of groups of special test electrodes outside through the plurality of groups of wiring terminals, the multi-channel measurement module, the plurality of groups of wiring terminals and the plurality of groups of special test electrodes are one-to-one corresponding, the power supply module is connected with an external power supply through the power supply interface, and the communication module is connected with an external host computer through the communication interface.

2. A multiple insulated resistance measuring device according to claim 1, wherein The power supply module comprises an AC / DC conversion element and an isolation element, the model of the AC / DC conversion element is LS15-23B05DR3, the model of the isolation element is A0509S-2WR2, an input pin of the AC / DC conversion element is connected with an external power supply, an output pin of the AC / DC conversion element outputs a first voltage, an input pin of the isolation element inputs a second voltage, and output pins of the isolation element output the second voltage and a third voltage, a first capacitor is connected between the first voltage and the ground, and a second capacitor and a third capacitor are connected between the second voltage and the third voltage and the ground respectively.

3. A multiple insulation resistance measuring device according to claim 2, wherein The AD conversion module comprises at least two AD converters and at least two reference voltage elements, the AD converters and the reference voltage elements are one-to-one corresponding, a clock pin, a chip selection pin, a serial data input pin and a serial data output pin of each AD converter are connected with the single-chip microcomputer, a main clock input pin and a main clock output pin of each AD converter are connected with a first crystal oscillator, one end of the first crystal oscillator is connected with one end of a fifth capacitor, the other end of the fifth capacitor is connected with the ground, and the other end of the fifth capacitor is connected with one end of a sixth capacitor, the other end of the sixth capacitor is connected with the ground, a reset pin of each AD converter is connected with one end of a second resistor, the other end of the second resistor is connected with the first voltage, a voltage pin of each AD converter is connected with the first voltage, the first voltage and the ground are connected with a seventh capacitor, an anode pin of each reference voltage element is connected with a reference input pin of each AD converter, the anode pin of the reference voltage element is connected with the first voltage through a third resistor, and a cathode pin of the reference voltage element is connected with the ground, the reference input pins of all the AD converters are connected, and analog signal input ends of all the AD converters are connected with the multi-channel measurement module, and the analog signal input end of one AD converter is further connected with the high-voltage sampling module.

4. A multiple insulation resistance measuring device according to claim 3, wherein The relay control module comprises a first relay element, a common terminal of the first relay element is connected with a first voltage, one end of a coil of the first relay element is connected with the first voltage, the other end of the coil of the first relay element is connected with a collector of a first transistor, an emitter of the first transistor is grounded, a base of the first transistor is connected with one end of a fourth resistor, the other end of the fourth resistor is connected with one end of a fifth resistor and a single-chip microcomputer respectively, a current monitoring pin of the first relay element is connected with the single-chip microcomputer, and a reference voltage pin of the first relay element is connected with an adjusting pin thereof.

5. A multiple insulation resistance measuring device according to claim 4, wherein The high-voltage sampling module comprises a first operational amplifier, a voltage pin of the first operational amplifier is connected with a second voltage and a third voltage, a positive input pin of the first operational amplifier is connected with one end of a ninth capacitor and one end of an eighth resistor respectively, the other end of the ninth capacitor is grounded, the other end of the eighth resistor is connected with one end of a ninth resistor and one end of a tenth resistor respectively, the other end of the ninth resistor is grounded, the other end of the tenth resistor is connected with one end of an eleventh resistor, the other end of the eleventh resistor is connected with one end of a twelfth resistor, the other end of the twelfth resistor is connected with one end of a thirteenth resistor, the other end of the thirteenth resistor is connected with one end of a fourteenth resistor, the other end of the fourteenth resistor is connected with a high voltage through a high-voltage terminal, an output pin of the first operational amplifier is connected with one end of a first diode and one end of a seventh resistor respectively, the other end of the first diode is connected with one end of an eighth capacitor, one end of a sixth resistor and the ground respectively, the other end of the sixth resistor is connected with the other end of the seventh resistor, the other end of the eighth capacitor and an AD conversion module respectively.

6. A multiple insulation resistance measuring device according to claim 5, wherein Each group of terminal includes high voltage terminal and low voltage terminal, the high voltage terminal connects the test positive electrode, the low voltage terminal connects the test negative electrode; the measurement circuit of each channel of the multi-channel measurement module includes a second operational amplifier and a second relay element, the voltage pin of the second operational amplifier is connected with the second voltage and the third voltage, the positive input pin of the second operational amplifier is connected with one end of the eleventh capacitor and one end of the seventeenth resistor respectively, the other end of the eleventh capacitor is grounded, the other end of the seventeenth resistor is connected with one end of the eighteenth resistor, the test positive electrode and one end of the inductor respectively, the other end of the inductor is connected with one end of the twelfth capacitor, the other end of the twelfth capacitor is connected with the test negative electrode and one end of the twenty-first resistor of the inductor respectively, the other end of the twenty-first resistor is connected with the high voltage; the other end of the eighteenth resistor is connected with one end of the nineteenth resistor and the normally open end of the second relay element respectively, the other end of the nineteenth resistor is connected with the common end of the second relay element, the normally closed end of the second relay element and the ground respectively, the voltage pin of the second relay element is connected with the first voltage, and the negative pin and the positive pin of the second relay element are connected with the third diode, the negative pin of the second relay element is also connected with the collector of the second transistor, the emitter of the second transistor is grounded, and the base of the second transistor is connected with one end of the twentieth resistor and the single-chip microcomputer respectively, the other end of the twentieth resistor is grounded; the output pin of the second operational amplifier is connected with one end of the second diode and one end of the sixteenth resistor respectively, the other end of the second diode is connected with one end of the tenth capacitor, one end of the fifteenth resistor and the ground respectively, the other end of the fifteenth resistor is connected with the other end of the sixteenth resistor, the other end of the tenth capacitor and the AD conversion module respectively.

7. A multiple insulation resistance measuring device according to claim 6, wherein The communication module includes an isolation transceiver and a communication serial port, the model of the isolation transceiver is TD501D485H, the communication serial port is an RS232 serial port, the differential signal input pin of the isolation transceiver is connected with the RS485 communication line, the signal sending pin, the signal receiving pin and the control pin of the isolation transceiver, and the signal sending pin and the signal receiving pin of the RS232 serial port are all connected with the single-chip microcomputer, the voltage pin of the isolation transceiver is connected with the first voltage, and the voltage pin of the RS232 serial port is connected with the first voltage and one end of the fourth capacitor respectively, the other end of the fourth capacitor is connected with one end of the first resistor and the single-chip microcomputer respectively, and the other end of the first resistor is grounded.

8. A multiple insulation resistance measuring device according to any one of claims 1 to 7, wherein The model of the single-chip microcomputer is STC12C5A60S2 LQFP44.