Insulation resistance testing device

Abstract

The present disclosure proposes an insulation resistance testing device, comprising: a voltage generating module, wherein the power supply end of the voltage generating module is connected to the power supply end of a DC power supply, and the power supply end of the voltage generating module is connected to the first end of the device under test; a sampling module, wherein the sampling end of the sampling module is connected to the second end of the device under test; a control module, wherein the communication end of the control module is respectively connected to the communication end of the voltage generating module and the communication end of the sampling module, and the control module is used to output a first control signal and a second control signal, so that the voltage generating module outputs negative polarity DC voltages of different levels according to the first control signal, and the sampling module continuously collects the current and voltage of the device under test according to the second control signal. In an insulation resistance testing device disclosed in the present disclosure, the testing device can realize automatic testing of the insulation resistance of the device under test, thereby effectively improving the testing efficiency of the insulation resistance and reducing the testing cost of the insulation resistance.

Description

Technical Field

[0001] The present disclosure relates to the technical field of insulation resistance testing, and in particular to an insulation resistance testing device. Background Art

[0002] Insulation resistance is the most basic insulation indicator for electrical equipment and electrical circuits. Electrical devices need to undergo insulation resistance testing during the manufacturing process to ensure the quality of the finished device. However, current insulation resistance testing mostly relies on manual operations, such as device pressurization, device test parameter reading and analysis, etc. The degree of automation is low, resulting in low insulation resistance test efficiency and test accuracy of the device and high test costs. Summary of the Invention

[0003] The present disclosure aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, an object of the present disclosure is to provide an insulation resistance testing device.

[0005] To achieve the above-mentioned objectives, the present disclosure provides an insulation resistance testing device, comprising: a voltage generating module, wherein the power supply end of the voltage generating module is connected to the power supply end of a DC power supply, and the power supply end of the voltage generating module is connected to the first end of the device under test; a sampling module, wherein the sampling end of the sampling module is connected to the second end of the device under test; a control module, wherein the communication end of the control module is respectively connected to the communication end of the voltage generating module and the communication end of the sampling module, the control module is used to output a first control signal and a second control signal, so that the voltage generating module outputs negative polarity DC voltages of different levels according to the first control signal, and the sampling module continuously collects the current and voltage of the device under test according to the second control signal, and the control module is further used to generate a test report based on the current and voltage of the device under test.

[0006] Optionally, the voltage generating module includes: a switching unit, a voltage doubling rectifier unit, a voltage stabilizing unit and a pulse width modulation control unit; wherein, the power supply end of the switching unit is connected to the power supply end of the DC power supply, the power supply end of the switching unit is connected to the power supply end of the voltage doubling rectifier unit, the power supply end of the voltage doubling rectifier unit is connected to the first end of the device under test, and the input end of the voltage stabilizing unit is connected to the power supply end of the voltage doubling rectifier unit; the input end of the pulse width modulation control unit is connected to the output end of the control module, the feedback end of the pulse width modulation control unit is connected to the output end of the voltage stabilizing unit, the output end of the pulse width modulation control unit is connected to the input end of the switching unit, the pulse width modulation control unit is used to control the switching unit according to the first control signal so that the voltage doubling rectifier unit outputs negative polarity DC voltages of different levels, and the pulse width modulation control unit is also used to control the switching unit according to the feedback voltage of the voltage stabilizing unit to stabilize the negative polarity DC voltage output by the voltage doubling rectifier unit.

[0007] Optionally, the switching unit includes: a first resistor, a second resistor, a first capacitor, a first transistor, a second transistor, a transformer, a third resistor, a first switch, and a second switch; wherein, the first end of the first resistor is connected to the emitter end of the first final transistor of the pulse width modulation control unit, the second end of the first resistor is grounded, the first end of the second resistor is connected to the emitter end of the second final transistor of the pulse width modulation control unit, the second end of the second resistor is grounded, the first end of the first capacitor is connected to the power supply end of the pulse width modulation control unit, and the second end of the first capacitor is grounded; the first transistor and the second transistor are respectively of NPN type, the base of the first transistor is connected to the first end of the second resistor, the collector of the first transistor is connected to the first end of the primary side of the transformer, and the first The emitter of the first transistor is connected to the collector of the second transistor, the base of the second transistor is connected to the first end of the first resistor, and the emitter of the second transistor is connected to the second end of the primary side of the transformer; the secondary side of the transformer is connected to the power supply end of the voltage doubler rectifier unit; the first end of the third resistor is connected to the emitter of the second transistor, and the second end of the third resistor is connected to the collector end of the first final transistor and the collector end of the second transistor of the pulse width modulation control unit; the negative electrode of the DC power supply is grounded, the positive electrode of the DC power supply is connected to the first end of the first switch, the second end of the first switch is connected to the first end of the first capacitor, the first end of the second switch is connected to the second end of the first switch, and the second end of the first switch is connected to the third end of the primary side of the transformer.

[0008] Optionally, the voltage doubling rectifier unit includes: a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a first diode, a second diode, a third diode and a fourth diode; wherein, the first end of the second capacitor is connected to the first end of the secondary side of the transformer, the first end of the fourth capacitor is connected to the second end of the second capacitor, the first end of the third capacitor is connected to the second end of the secondary side of the transformer, the first end of the fifth capacitor is connected to the second end of the third capacitor, and the second end of the fifth capacitor is connected to the first end of the device under test; the anode of the first diode is connected to the second end of the second capacitor, the cathode of the first diode is connected to the first end of the third capacitor, the anode of the second diode is connected to the second end of the third capacitor, the cathode of the second diode is connected to the first end of the fourth capacitor, the anode of the third diode is connected to the second end of the fourth capacitor, the cathode of the third diode is connected to the first end of the fifth capacitor, the anode of the fourth diode is connected to the second end of the fifth capacitor, and the cathode of the fourth diode is connected to the second end of the fourth capacitor.

[0009] Optionally, the voltage stabilizing unit includes: a sixth capacitor, a fourth resistor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a third switch, a fourth switch, a fifth switch and a sixth switch; wherein, the first end of the sixth capacitor is connected to the inverting input end of the comparison amplifier of the pulse width modulation control unit, the second end of the sixth capacitor is connected to the common output end of the pulse width modulation control unit, the first end of the fourth resistor is connected to the first end of the sixth capacitor, the second end of the fourth resistor is connected to the output function control end of the pulse width modulation control unit, the first end of the seventh capacitor is connected to the first end of the fourth resistor, the second end of the seventh capacitor is connected to the second end of the fourth resistor, the first end of the eighth capacitor is connected to the first end of the seventh capacitor, and the second end of the eighth capacitor is connected to the common output end of the pulse width modulation control unit. the second end of the seventh capacitor is connected; the first end of the ninth capacitor is connected to the first end of the eighth capacitor, the first end of the tenth capacitor is connected to the second end of the ninth capacitor, the first end of the eleventh capacitor is connected to the second end of the tenth capacitor, the first end of the twelfth capacitor is connected to the second end of the eleventh capacitor, and the second end of the twelfth capacitor is connected to the first end of the device under test; the first end of the fifth resistor is connected to the first end of the ninth capacitor, the second end of the fifth resistor is connected to the second end of the ninth capacitor, the first end of the sixth resistor is connected to the first end of the tenth capacitor, the second end of the sixth resistor is connected to the second end of the tenth capacitor, the first end of the seventh resistor is connected to the first end of the eleventh capacitor, the second end of the seventh resistor is connected to the second end of the eleventh capacitor, the first end of the eighth resistor is connected to the first end of the twelfth capacitor, and the second end of the eighth resistor is connected to the second end of the twelfth capacitor;A first end of the ninth resistor is connected to a non-inverting input end of the comparison amplifier of the pulse width modulation control unit, a second end of the ninth resistor is grounded, a first end of the tenth resistor is connected to a second end of the eighth capacitor, a second end of the tenth resistor is connected to a first end of the third switch, a second end of the third switch is connected to a first end of the ninth resistor, a first end of the eleventh resistor is connected to a first end of the tenth resistor, a second end of the eleventh resistor is connected to a first end of the fourth switch, a second end of the fourth switch is connected to a second end of the third switch, a first end of the twelfth resistor is connected to a first end of the eleventh resistor, a second end of the twelfth resistor is connected to a first end of the fifth switch, a second end of the fifth switch is connected to a second end of the fourth switch, a first end of the thirteenth resistor is connected to a first end of the twelfth resistor, a second end of the thirteenth resistor is connected to a first end of the sixth switch, and a second end of the sixth switch is connected to a second end of the fifth switch.

[0010] Optionally, the sampling module includes: a reference resistor, a sampling resistor, a first sampling unit, and a second sampling unit; wherein, the first end of the reference resistor is connected to the power supply end of the voltage generating module to form a reference path, and the first end of the sampling resistor is connected to the second end of the device under test to form a test path; the first end of the first sampling unit is connected to the second end of the reference resistor, the second end of the first sampling unit is connected to the second end of the sampling resistor, and the third end of the first sampling unit is connected to the communication end of the control module, and the first sampling unit is used to collect the current and voltage of the reference path; the first end of the second sampling unit is connected to the first end of the sampling resistor, the second end of the second sampling unit is connected to the input end of the control module, and the second sampling unit is used to collect the current and voltage of the test path; the control module is used to obtain the current and voltage of the device under test based on the current and voltage of the reference path and the current and voltage of the test path.

[0011] Optionally, the first sampling unit includes: a decoder, four bidirectional analog switches, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a first filter, a second filter, a first analog-to-digital converter and a second analog-to-digital converter; wherein the input end of the decoder is connected to the output end of the control module, and the output end of the decoder is connected to the control end of the four bidirectional analog switches; the first end of the fourteenth resistor is connected to the second end of the fifteenth resistor, the second end of the fourteenth resistor is connected to the second end of the reference resistor, and the first end of the fifteenth resistor is connected to the second end of the sampling resistor; the first end of the sixteenth resistor is connected to the first end of the four bidirectional analog switches, the second end of the sixteenth resistor is connected to the first end of the fifteenth resistor, and the first end of the seventeenth resistor is connected to the first end of the sampling resistor. The second ends of the four bidirectional analog switches are connected, the second end of the seventeenth resistor is connected to the second end of the sixteenth resistor, the third end of the four bidirectional analog switches is grounded, the first end of the eighteenth resistor is connected to the second end of the fourteenth resistor, the second end of the eighteenth resistor is connected to the first end of the nineteenth resistor, and the second end of the nineteenth resistor is grounded; the input end of the first filter is connected to the second end of the seventeenth resistor, the output end of the first filter is connected to the input end of the first analog-to-digital converter, and the output end of the first analog-to-digital converter is connected to the input end of the control module; the input end of the second filter is connected to the first end of the nineteenth resistor, the output end of the second filter is connected to the input end of the second analog-to-digital converter, and the output end of the second analog-to-digital converter is connected to the input end of the control module.

[0012] Optionally, the second sampling unit includes: a twentieth resistor, a twenty-first resistor, a first operational amplifier, a second operational amplifier, a twenty-second resistor and a thirteenth capacitor; wherein, the first input terminal of the first operational amplifier is connected to the first end of the twentieth resistor, the second input terminal of the first operational amplifier is connected to the second end of the twentieth resistor, the first compensation terminal of the first operational amplifier is connected to the first end of the sampling resistor, the second compensation terminal of the first operational amplifier is grounded, and the power supply terminal of the first operational amplifier is connected to the power supply terminal of the first power supply; the first input terminal of the second operational amplifier inputs a reference voltage, the second input terminal of the second operational amplifier is connected to the first end of the twenty-first resistor, the second end of the twenty-first resistor is connected to the reference terminal of the first operational amplifier, the power supply terminal of the second operational amplifier is connected to the power supply terminal of the second power supply; the first end of the twenty-second resistor is connected to the output terminal of the first operational amplifier, the second end of the twenty-second resistor is connected to the input terminal of the control module, the first end of the thirteenth capacitor is connected to the second end of the twenty-second resistor, and the second end of the thirteenth capacitor is grounded.

[0013] Optionally, the sampling module further includes: a protection unit, which is connected in series between the first end of the sampling resistor and the second end of the device under test, and is used to disconnect the path between the sampling resistor and the device under test when the current in the test path exceeds a set threshold.

[0014] Optionally, the control module includes: a single-chip microcomputer and an industrial computer; wherein the communication end of the single-chip microcomputer is respectively connected to the communication end of the voltage generating module and the communication end of the sampling module, and the single-chip microcomputer is used to output a first control signal and a second control signal, so that the voltage generating module outputs different levels of negative polarity DC voltage according to the first control signal, and the sampling module collects the current and voltage of the device under test according to the second control signal; the communication end of the industrial computer is connected to the communication end of the single-chip microcomputer, and the industrial computer is used to generate a current-time curve and a current-voltage curve according to the current and voltage of the device under test, and generate the test report according to the current-time curve and the current-voltage curve.

[0015] The technical solution provided by the present disclosure may have the following beneficial effects:

[0016] Under the control of the control module, the voltage generation module can be used to output negative polarity DC voltages of different levels, and the sampling module can be used to continuously collect the current and voltage of the device under test, and a test report can be generated based on the current and voltage of the device under test, so that the test device can automatically test the insulation resistance of the device under test, thereby effectively improving the test efficiency of the insulation resistance and reducing the test cost of the insulation resistance. At the same time, due to the continuous collection of the current and voltage of the device under test and the generation of the test report based on the continuously collected current and voltage, the test data of the insulation resistance of the device under test by the test device is more comprehensive, thereby effectively improving the test accuracy of the insulation resistance.

[0017] Additional aspects and advantages of the present disclosure will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present disclosure will become apparent and readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0019] Figure 1 1 is a circuit diagram of an insulation resistance testing device according to an embodiment of the present disclosure;

[0020] Figure 2 This is a circuit diagram of a voltage generating module in an insulation resistance testing device according to an embodiment of the present disclosure;

[0021] Figure 3 1 is a circuit diagram of a first sampling unit in an insulation resistance testing device according to an embodiment of the present disclosure;

[0022] Figure 4 1 is a circuit diagram of a second sampling unit in an insulation resistance testing device according to an embodiment of the present disclosure;

[0023] As shown in the figure: 1. Voltage generating module, 11. Switching unit, 12. Voltage doubling and rectifying unit, 13. Voltage stabilizing unit, 14. Pulse width modulation control unit;

[0024] 2. Sampling module;

[0025] 21. First sampling unit, 211. Decoder, 212. Quad bidirectional analog switches, 213. First filter, 214. Second filter, 215. First analog-to-digital converter, 216. Second analog-to-digital converter;

[0026] 22. Second sampling unit, 23. Protection unit;

[0027] 3. Control module, 31. Single chip microcomputer, 32. Industrial computer;

[0028] Ra, reference resistor, Rb, sampling resistor, Rx, device under test;

[0029] R1, the first resistor, R2, the second resistor, R3, the third resistor, R4, the fourth resistor, R5, the fifth resistor, R6, the sixth resistor, R7, the seventh resistor, R8, the eighth resistor, R9, the ninth resistor, R10, the tenth resistor, R11, the eleventh resistor, R12, the twelfth resistor, R13, the thirteenth resistor, R14, the fourteenth resistor, R15, the fifteenth resistor, R16, the sixteenth resistor, R17, the seventeenth resistor, R18, the eighteenth resistor, R19, the nineteenth resistor, R20, the twentieth resistor, R21, the twenty-first resistor, and R22, the twenty-second resistor;

[0030] C1, first capacitor, C2, second capacitor, C3, third capacitor, C4, fourth capacitor, C5, fifth capacitor, C6, sixth capacitor, C7, seventh capacitor, C8, eighth capacitor, C9, ninth capacitor, C10, tenth capacitor, C11, eleventh capacitor, C12, twelfth capacitor, C13, thirteenth capacitor;

[0031] Q1, the first transistor, Q2, the second transistor;

[0032] D1, the first diode, D2, the second diode, D3, the third diode, D4, the fourth diode;

[0033] S1, first switch, S2, second switch, S3, third switch, S4, fourth switch, S5, fifth switch, S6, sixth switch;

[0034] U, transformer;

[0035] OP1, the first operational amplifier; OP2, the second operational amplifier. DETAILED DESCRIPTION

[0036] The following describes in detail embodiments of the present disclosure, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present disclosure and are not to be construed as limiting the present disclosure. On the contrary, the embodiments of the present disclosure include all variations, modifications, and equivalents that fall within the spirit and scope of the appended claims.

[0037] like Figure 1 As shown, an embodiment of the present disclosure proposes an insulation resistance testing device, including: a voltage generating module 1, a sampling module 2 and a control module 3, the power supply end of the voltage generating module 1 is connected to the power supply end of the DC power supply, the power supply end of the voltage generating module 1 is connected to the first end of the device under test Rx, the sampling end of the sampling module 2 is connected to the second end of the device under test Rx, the communication end of the control module 3 is connected to the communication end of the voltage generating module 1 and the communication end of the sampling module 2 respectively, the control module 3 is used to output a first control signal and a second control signal, so that the voltage generating module 1 outputs negative polarity DC voltages of different levels according to the first control signal, and the sampling module 2 continuously collects the current and voltage of the device under test Rx according to the second control signal, and the control module 3 is further used to generate a test report according to the current and voltage of the device under test Rx.

[0038] It can be understood that since the communication end of the control module 3 is respectively connected to the communication end of the voltage generating module 1 and the communication end of the sampling module 2, the control module 3 can output a first control signal to the voltage generating module 1 and a second control signal to the sampling module 2. Moreover, since the power supply end of the voltage generating module 1 is connected to the power supply end of the DC power supply, and the power supply end of the voltage generating module 1 is connected to the first end of the device under test Rx, the voltage generating module 1 can output negative polarity DC voltages of different levels according to the first control signal. At the same time, since the sampling end of the sampling module 2 is connected to the second end of the device under test Rx, the sampling module 2 can continuously collect the current and voltage of the device under test Rx according to the second control signal.

[0039] Among them, under the control of the control module 3, the voltage generating module 1 can be used to output negative polarity DC voltages of different levels, and the sampling module 2 can be used to continuously collect the current and voltage of the device under test Rx, and a test report can be generated based on the current and voltage of the device under test Rx, so that the test device can automatically test the insulation resistance of the device under test Rx, thereby effectively improving the test efficiency of the insulation resistance and reducing the test cost of the insulation resistance. At the same time, due to the continuous collection of the current and voltage of the device under test Rx and the generation of the test report based on the continuously collected current and voltage, the test data of the insulation resistance of the device under test Rx by the test device is more comprehensive, thereby effectively improving the test accuracy of the insulation resistance.

[0040] It should be noted that the voltage generating module 1 is configured to convert the output power of the DC power supply according to the first control signal to output different levels of negative polarity DC voltage to the device under test Rx. The specific type of the voltage generating module 1 can be set according to actual needs and is not limited thereto. Specifically, the voltage generating module 1 can continuously output an increasing negative polarity DC voltage according to the first control signal.

[0041] The sampling module 2 is used to continuously collect the current and voltage of the device under test Rx according to the second control signal when the voltage generating module 1 outputs different levels of negative polarity DC voltage to the device under test Rx. The specific type of the sampling module 2 can be set according to actual needs and is not limited to this.

[0042] The control module 3 is used to output a first control signal to the voltage generating module 1 and a second control signal to the sampling module 2. It is also used to generate a test report based on the current and voltage of the device under test Rx. The specific type of the control module 3 can be set according to actual needs and is not limited to this.

[0043] The DC power supply is used to output DC power. The specific type of the DC power supply can be set according to actual needs and is not limited to this.

[0044] The test report is used to intuitively characterize the test parameters of the device under test Rx, including: current, voltage, time, insulation resistance, etc.

[0045] like Figure 1As shown, in some embodiments, the voltage generating module 1 includes: a switching unit 11, a voltage doubling and rectifying unit 12, a voltage stabilizing unit 13 and a pulse width modulation control unit 14; wherein, the power supply end of the switching unit 11 is connected to the power supply end of the DC power supply, the power supply end of the switching unit 11 is connected to the power supply end of the voltage doubling and rectifying unit 12, the power supply end of the voltage doubling and rectifying unit 12 is connected to the first end of the device under test Rx, the input end of the voltage stabilizing unit 13 is connected to the power supply end of the voltage doubling and rectifying unit 12, the input end of the pulse width modulation control unit 14 is connected to the output end of the control module 3, the feedback end of the pulse width modulation control unit 14 is connected to the output end of the voltage stabilizing unit 13, the output end of the pulse width modulation control unit 14 is connected to the input end of the switching unit 11, the pulse width modulation control unit 14 is used to control the switching unit 11 according to the first control signal so that the voltage doubling and rectifying unit 12 outputs negative polarity DC voltages of different levels, and the pulse width modulation control unit 14 is further used to control the switching unit 11 according to the feedback voltage of the voltage stabilizing unit 13 to stabilize the negative polarity DC voltage output by the voltage doubling and rectifying unit 12.

[0046] It can be understood that since the input end of the pulse width modulation control unit 14 is connected to the output end of the control module 3, and the output end of the pulse width modulation control unit 14 is connected to the input end of the switch unit 11, the pulse width modulation control unit 14 can control the switch unit 11 according to the first control signal, and since the power supply end of the switch unit 11 is connected to the power supply end of the DC power supply, and the power supply end of the switch unit 11 is connected to the power supply end of the voltage doubler rectifier unit 12, and the power supply end of the voltage doubler rectifier unit 12 is connected to the first end of the device under test Rx, the electric energy output by the DC power supply can output different levels of negative polarity DC voltage to the device under test Rx under the on-off action of the switch unit 11 and the amplification and rectification action of the voltage doubler rectifier unit 12. At the same time, since the feedback end of the pulse width modulation control unit 14 is connected to the output end of the voltage stabilizing unit 13, the pulse width modulation control unit 14 can control the switch unit 11 according to the feedback voltage of the voltage stabilizing unit 13, thereby stabilizing the negative polarity DC voltage output by the voltage doubler rectifier unit 12. Therefore, through the cooperation of the switch unit 11 , the voltage doubler and rectifier unit 12 , the voltage stabilizing unit 13 and the pulse width modulation control unit 14 , the testing device can achieve stable and continuous voltage application to the device under test Rx.

[0047] It should be noted that the pulse width modulation control unit 14 is used to control the switching unit 11 so that the voltage doubler rectifier unit 12 outputs different levels of negative polarity DC voltage, while ensuring that each level of negative polarity DC voltage can be stabilized within a very small set range. The specific type of the pulse width modulation control unit 14 can be set according to actual needs and is not limited to this. For example, the pulse width modulation control unit 14 can be a TL494 chip. The TL494 chip is an integrated chip that can provide a fixed frequency and adjustable pulse width, and belongs to a pulse width modulation control circuit. The TL494 chip will obtain different pulse widths by setting different square wave duty cycles, and different levels of negative polarity DC voltage of the voltage doubler rectifier unit 12 can be achieved by adjusting the width of the pulse.

[0048] Among them, the TL494 chip has a total of sixteen pins, and only the pins involved in this embodiment are introduced here. Specifically, the third pin of the TL494 chip is the common output terminal of the control comparator amplifier and the error comparator amplifier, and exhibits an output control characteristic when outputting, that is, of the two amplifiers, the one with the larger output amplitude takes effect. When the level of the third pin becomes high, the width of the driving pulse sent from the output terminal becomes narrower, and when the level of the third pin is low, the width of the driving pulse becomes wider. The third pin can be connected to the output terminal of the control module 3; the eighth pin of the TL494 chip is the collector power supply terminal of the first final-stage transistor; TL49 The ninth pin of the TL494 chip is the emitter power supply terminal of the first final-stage transistor; the tenth pin of the TL494 chip is the collector power supply terminal of the second final-stage transistor; the eleventh pin of the TL494 chip is the emitter power supply terminal of the second final-stage transistor; the twelfth pin of the TL494 chip is the working power supply terminal; the thirteenth pin of the TL494 chip is the output function control terminal, that is, the internal circuit reset control terminal, and the output control is used to control the output state of the two square waves; the fifteenth pin of the TL494 chip is the inverting input terminal of the control comparator amplifier; the sixteenth pin of the TL494 chip is the non-inverting input terminal of the control comparator amplifier.

[0049] The switch unit 11 is used to control the output power of the DC power supply by switching on and off. The specific type of the switch unit 11 can be set according to actual needs and is not limited to this.

[0050] The voltage doubler and rectifier unit 12 is used to amplify and rectify the electric energy output by the switch unit 11 . The specific type of the voltage doubler and rectifier unit 12 can be set according to actual needs and is not limited thereto.

[0051] The voltage stabilizing unit 13 is used to stabilize the electric energy output by the voltage doubling and rectifying unit 12 . The specific type of the voltage stabilizing unit 13 can be set according to actual needs and is not limited thereto.

[0052] In a specific application, the voltage generating module 1 can enable the pulse width modulation control unit 14 to output an analog value of 0V-5V, so as to control the output of the voltage doubler rectifier unit 12 to be 0V-10000V.

[0053] like Figure 2 As shown, in some embodiments, the switch unit 11 includes: a first resistor R1, a second resistor R2, a first capacitor C1, a first transistor Q1, a second transistor Q2, a transformer U, a third resistor R3, a first switch S1 and a second switch S2; wherein, the first end of the first resistor R1 is connected to the emitter end of the first final transistor of the pulse width modulation control unit 14, the second end of the first resistor R1 is grounded, the first end of the second resistor R2 is connected to the emitter end of the second final transistor of the pulse width modulation control unit 14, the second end of the second resistor R2 is grounded, the first end of the first capacitor C1 is connected to the power supply end of the pulse width modulation control unit 14, the second end of the first capacitor C1 is grounded, the first transistor Q1 and the second transistor Q2 are respectively NPN type, the base of the first transistor Q1 is connected to the first end of the second resistor R2, and the collector of the first transistor Q1 is connected to the transformer U. The first end of the primary side of the transformer U is connected, the emitter of the first transistor Q1 is connected to the collector of the second transistor Q2, the base of the second transistor Q2 is connected to the first end of the first resistor R1, the emitter of the second transistor Q2 is connected to the second end of the primary side of the transformer U, the secondary side of the transformer U is connected to the power supply end of the voltage doubling rectifier unit 12, the first end of the third resistor R3 is connected to the emitter of the second transistor Q2, the second end of the third resistor R3 is connected to the collector end of the first final-stage transistor and the collector end of the second transistor Q2 of the pulse width modulation control unit 14, the negative electrode of the DC power supply is grounded, the positive electrode of the DC power supply is connected to the first end of the first switch S1, the second end of the first switch S1 is connected to the first end of the first capacitor C1, the first end of the second switch S2 is connected to the second end of the first switch S1, and the second end of the first switch S1 is connected to the third end of the primary side of the transformer U.

[0054] It can be understood that the control circuit of the DC power supply is formed by the cooperation of the first resistor R1, the second resistor R2, the first capacitor C1, the first transistor Q1, the second transistor Q2 and the third resistor R3. When the first final-stage transistor emitter and the second final-stage transistor emitter of the pulse width modulation control unit 14 output an adjustable pulse signal, the conduction and cutoff of the first transistor Q1 and the second transistor Q2 can be utilized to make the DC power supply output voltages of different sizes, thereby facilitating the use of the voltage doubler rectifier unit 12 to achieve different levels of output of negative polarity DC voltage, thereby meeting the test requirements of the device under test Rx.

[0055] It should be noted that the specific resistance values of the first resistor R1 , the second resistor R2 and the third resistor R3 can be set according to actual needs and are not limited thereto.

[0056] The specific capacitance value of the first capacitor C1 can be set according to actual needs and is not limited thereto.

[0057] The first transistor Q1 and the second transistor Q2 are both NPN transistors. An NPN transistor is a transistor composed of two N-type semiconductors with a P-type semiconductor sandwiched between them. It has a base, a collector, and an emitter. The specific types of the first transistor Q1 and the second transistor Q2 can be set according to actual needs and are not limited to this.

[0058] The transformer U is used for power conversion between the DC power supply and the voltage doubler rectifier unit 12 . The specific type of the transformer U can be set according to actual needs and is not limited thereto.

[0059] The first switch S1 and the second switch S2 are used to control the on / off of the path between the DC power supply and the transformer U. The specific types of the first switch S1 and the second switch S2 can be set according to actual needs and are not limited thereto.

[0060] like Figure 2 As shown, in some embodiments, the voltage doubler rectifier unit 12 includes: a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4; wherein the first end of the second capacitor C2 is connected to the first end of the secondary side of the transformer U, the first end of the fourth capacitor C4 is connected to the second end of the second capacitor C2, the first end of the third capacitor C3 is connected to the second end of the secondary side of the transformer U, the first end of the fifth capacitor C5 is connected to the second end of the third capacitor C3, and the second end of the fifth capacitor C5 is connected to the device under test R The first end of x is connected to the first end of x, the anode of the first diode D1 is connected to the second end of the second capacitor C2, the cathode of the first diode D1 is connected to the first end of the third capacitor C3, the anode of the second diode D2 is connected to the second end of the third capacitor C3, the cathode of the second diode D2 is connected to the first end of the fourth capacitor C4, the anode of the third diode D3 is connected to the second end of the fourth capacitor C4, the cathode of the third diode D3 is connected to the first end of the fifth capacitor C5, the anode of the fourth diode D4 is connected to the second end of the fifth capacitor C5, and the cathode of the fourth diode D4 is connected to the second end of the fourth capacitor C4.

[0061] It can be understood that by coordinating the conduction and cutoff of the first diode D1, the second diode D2, the third diode D3 and the fourth diode D4, the second capacitor C2, the third capacitor C3, the fourth capacitor C4 and the fifth capacitor C5 are charged step by step, following the principle of unidirectional conduction of the diode and non-mutation of the two ends of the capacitor, to achieve voltage doubling and rectification functions, thereby meeting the test requirements of the device under test Rx.

[0062] It should be noted that the specific capacitance values of the second capacitor C2 , the third capacitor C3 , the fourth capacitor C4 and the fifth capacitor C5 can be set according to actual needs and are not limited thereto.

[0063] The first diode D1, the second diode D2, the third diode D3 and the fourth diode D4 are all diodes with a unidirectional conduction function. The specific types of the first diode D1, the second diode D2, the third diode D3 and the fourth diode D4 can be set according to actual needs and are not limited to this.

[0064] like Figure 2As shown, in some embodiments, the voltage stabilizing unit 13 includes: a sixth capacitor C6, a fourth resistor R4, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10, an eleventh capacitor C11, a twelfth capacitor C12, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a third switch S3, a fourth switch S4, a fifth switch S5, and a sixth switch S6;Among them, the first end of the sixth capacitor C6 is connected to the inverting input terminal of the comparison amplifier of the pulse width modulation control unit 14, the second end of the sixth capacitor C6 is connected to the common output terminal of the pulse width modulation control unit 14, the first end of the fourth resistor R4 is connected to the first end of the sixth capacitor C6, the second end of the fourth resistor R4 is connected to the output function control terminal of the pulse width modulation control unit 14, the first end of the seventh capacitor C7 is connected to the first end of the fourth resistor R4, the second end of the seventh capacitor C7 is connected to the second end of the fourth resistor R4, the first end of the eighth capacitor C8 is connected to the first end of the seventh capacitor C7, the second end of the eighth capacitor C8 is connected to the second end of the seventh capacitor C7, and the ninth capacitor C9 is connected to the first end of the seventh capacitor C7. The first end of the first resistor R5 is connected to the first end of the ninth capacitor C9, the first end of the sixth resistor R6 is connected to the first end of the tenth capacitor C10, the second end of the sixth resistor R6 is connected to the second end of the tenth capacitor C10, the first end of the seventh resistor R7 is connected to the first end of the ninth capacitor C8, the first end of the tenth capacitor C10 is connected to the second end of the ninth capacitor C9, the first end of the eleventh capacitor C11 is connected to the second end of the tenth capacitor C10, the first end of the twelfth capacitor C12 is connected to the second end of the eleventh capacitor C11, the second end of the twelfth capacitor C12 is connected to the first end of the device under test Rx, the first end of the fifth resistor R5 is connected to the first end of the ninth capacitor C9, the second end of the fifth resistor R5 is connected to the second end of the ninth capacitor C9, the first end of the sixth resistor R6 is connected to the first end of the tenth capacitor C10, the second end of the sixth resistor R6 is connected to the second end of the tenth capacitor C10, and the seventh resistor R A first end of the seventh resistor R7 is connected to a first end of the eleventh capacitor C11, a second end of the seventh resistor R7 is connected to a second end of the eleventh capacitor C11, a first end of the eighth resistor R8 is connected to a first end of the twelfth capacitor C12, a second end of the eighth resistor R8 is connected to a second end of the twelfth capacitor C12, a first end of the ninth resistor R9 is connected to a non-inverting input end of the comparison amplifier of the pulse width modulation control unit 14, a second end of the ninth resistor R9 is grounded, a first end of the tenth resistor R10 is connected to a second end of the eighth capacitor C8, a second end of the tenth resistor R10 is connected to a first end of the third switch S3, a second end of the third switch S3 is connected to a first end of the ninth resistor R9, and the eleventh resistor R A first end of a resistor R11 is connected to a first end of a tenth resistor R10, a second end of an eleventh resistor R11 is connected to a first end of a fourth switch S4, a second end of the fourth switch S4 is connected to a second end of the third switch S3, a first end of a twelfth resistor R12 is connected to a first end of the eleventh resistor R11, a second end of the twelfth resistor R12 is connected to a first end of a fifth switch S5, a second end of the fifth switch S5 is connected to a second end of the fourth switch S4, a first end of a thirteenth resistor R13 is connected to a first end of the twelfth resistor R12, a second end of the thirteenth resistor R13 is connected to a first end of a sixth switch S6, and a second end of the sixth switch S6 is connected to a second end of the fifth switch S5.

[0065] It can be understood that, through the cooperation of the sixth capacitor C6, the fourth resistor R4, the seventh capacitor C7, the eighth capacitor C8, the ninth capacitor C9, the tenth capacitor C10, the eleventh capacitor C11, the twelfth capacitor C12, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, the eleventh resistor R11, the twelfth resistor R12, the thirteenth resistor R13, the third switch S3, the fourth switch S4, the fifth switch S5, and the sixth switch S6, sampling of the voltage at the device under test Rx and establishment of the reference voltage at the pulse width modulation control unit 14 are achieved. At the same time, the error voltage between the sampled voltage and the reference voltage is fed back to the pulse width modulation control unit 14, so that the pulse width modulation control unit 14 can adjust the voltage drops of the first transistor Q1 and the second transistor Q2 according to the error voltage, thereby achieving voltage stabilization at the device under test Rx.

[0066] It should be noted that the specific capacitance values of the sixth capacitor C6, the seventh capacitor C7, the eighth capacitor C8, the ninth capacitor C9, the tenth capacitor C10, the eleventh capacitor C11 and the twelfth capacitor C12 can be set according to actual needs and are not limited thereto.

[0067] The specific resistance values of the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, the eleventh resistor R11, the twelfth resistor R12 and the thirteenth resistor R13 can be set according to actual needs and are not limited to this.

[0068] The third switch S3, the fourth switch S4, the fifth switch S5, and the sixth switch S6 are used to adjust the impedance between the tenth resistor R10, the eleventh resistor R11, the twelfth resistor R12, and the thirteenth resistor R13. The specific types of the third switch S3, the fourth switch S4, the fifth switch S5, and the sixth switch S6 can be set according to actual needs and are not limited thereto.

[0069] like Figure 1As shown, in some embodiments, the sampling module 2 includes: a reference resistor Ra, a sampling resistor Rb, a first sampling unit 21, and a second sampling unit 22; wherein a first end of the reference resistor Ra is connected to the power supply end of the voltage generating module 1 to form a reference path, a first end of the sampling resistor Rb is connected to the second end of the device under test Rx to form a test path, a first end of the first sampling unit 21 is connected to the second end of the reference resistor Ra, a second end of the first sampling unit 21 is connected to the second end of the sampling resistor Rb, and a third end of the first sampling unit 21 is connected to a communication end of the control module 3. The first sampling unit 21 is configured to collect current and voltage of the reference path, a first end of the second sampling unit 22 is connected to the first end of the sampling resistor Rb, a second end of the second sampling unit 22 is connected to an input end of the control module 3, and the second sampling unit 22 is configured to collect current and voltage of the test path. The control module 3 is configured to obtain current and voltage of the device under test Rx based on the current and voltage of the reference path and the current and voltage of the test path.

[0070] It can be understood that, since the first end of the reference resistor Ra is connected to the power supply end of the voltage generating module 1, and the first end of the first sampling unit 21 is connected to the second end of the reference resistor Ra, the first sampling unit 21 can obtain the current and voltage of the reference path. At the same time, since the first end of the device under test Rx is connected to the power supply end of the voltage generating module 1, the first end of the sampling resistor Rb is connected to the second end of the device under test Rx, and the first end of the second sampling unit 22 is connected to the first end of the sampling resistor Rb, the second sampling unit 22 can obtain the current and voltage of the test path.

[0071] At the same time, since the third end of the first sampling unit 21 is connected to the communication end of the control module 3, and the second end of the second sampling unit 22 is connected to the input end of the control module 3, the control module 3 can use the first sampling unit 21 to obtain the current and voltage of the reference path, and use the second sampling unit 22 to obtain the current and voltage of the test path, thereby obtaining the current and voltage of the device under test Rx based on the current and voltage of the reference path and the current and voltage of the test path, thereby realizing accurate testing of the insulation resistance of the device under test Rx.

[0072] It should be noted that the reference path includes: a reference resistor Ra, and the test path includes: a device under test Rx and a sampling resistor Rb. Since the reference path and the test path are connected in parallel, the current and voltage of the reference path and the resistance value of the reference resistor Ra can provide reference values for the device under test Rx. At the same time, since the current of the device under test Rx and the current of the sampling resistor Rb are equal, the current of the device under test Rx can be obtained by using the current of the sampling resistor Rb, thereby realizing the insulation resistance test of the device under test Rx.

[0073] The reference resistor Ra is used to provide a reference value for the device under test Rx. The specific resistance value of the reference resistor Ra can be set according to actual needs and is not limited thereto.

[0074] The sampling resistor Rb is used to convert the current and voltage in the test path into voltage and current signals proportional to them for measurement. By means of resistor voltage division, part of the current and voltage in the test path is converted into measurable signals. The specific resistance value of the sampling resistor Rb can be set according to actual needs and is not limited to this.

[0075] The specific types of the first sampling unit 21 and the second sampling unit 22 can be set according to actual needs and are not limited thereto.

[0076] like Figure 3 As shown, in some embodiments, the first sampling unit 21 includes: a decoder 211, a four-way analog switch 212, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, a nineteenth resistor R19, a first filter 213, a second filter 214, a first analog-to-digital converter 215, and a second analog-to-digital converter 216; wherein the input end of the decoder 211 is connected to the output end of the control module 3, the output end of the decoder 211 is connected to the control end of the four-way analog switch 212, the first end of the fourteenth resistor R14 is connected to the second end of the fifteenth resistor R15, the second end of the fourteenth resistor R14 is connected to the second end of the reference resistor Ra, the first end of the fifteenth resistor R15 is connected to the second end of the sampling resistor Rb, the first end of the sixteenth resistor R16 is connected to the first end of the four-way analog switch 212, the second end of the sixteenth resistor R16 is connected to the first end of the fifteenth resistor R15 One end of the first filter 213 is connected to the second end of the seventeenth resistor R17, the first end of the seventeenth resistor R17 is connected to the second end of the quad bidirectional analog switch 212, the second end of the seventeenth resistor R17 is connected to the second end of the sixteenth resistor R16, the third end of the quad bidirectional analog switch 212 is grounded, the first end of the eighteenth resistor R18 is connected to the second end of the fourteenth resistor R14, the second end of the eighteenth resistor R18 is connected to the first end of the nineteenth resistor R19, the second end of the nineteenth resistor R19 is grounded, the input end of the first filter 213 is connected to the second end of the seventeenth resistor R17, the output end of the first filter 213 is connected to the input end of the first analog-to-digital converter 215, the output end of the first analog-to-digital converter 215 is connected to the input end of the control module 3, the input end of the second filter 214 is connected to the first end of the nineteenth resistor R19, the output end of the second filter 214 is connected to the input end of the second analog-to-digital converter 216, and the output end of the second analog-to-digital converter 216 is connected to the input end of the control module 3.

[0077] It can be understood that the control module 3 drives and controls the four bidirectional analog switches 212 through the decoder 211, so as to realize the switch control of the first sampling unit 21 by utilizing the on and off of the four bidirectional analog switches 212, and after the first sampling unit 21 is turned on, it can utilize the cooperation of the fourteenth resistor R14, the fifteenth resistor R15, the sixteenth resistor R16, the seventeenth resistor R17, the eighteenth resistor R18 and the nineteenth resistor R19, as well as the filtering of the first filter 213 and the second filter 214, and the analog-to-digital conversion of the first analog-to-digital converter 215 and the second analog-to-digital converter 216 to obtain the current and voltage of the reference path, thereby obtaining the current and voltage of the device under test Rx based on the current and voltage of the reference path and the current and voltage of the test path, thereby realizing accurate testing of the insulation resistance of the device under test Rx.

[0078] It should be noted that the specific resistance values of the fourteenth resistor R14 , the fifteenth resistor R15 , the sixteenth resistor R16 , the seventeenth resistor R17 , the eighteenth resistor R18 and the nineteenth resistor R19 can be set according to actual needs and are not limited thereto.

[0079] The specific type of the decoder 211 can be set according to actual needs and is not limited to this. For example, the decoder 211 can use a 74HC238 chip. The 74HC238 chip is a three-line to eight-line decoder 211 or multiplexer with the characteristics of high speed and low power consumption. The 74HC238 chip has three binary-weighted address inputs and eight mutually exclusive outputs. It can decode the input three-bit binary address code into eight-bit output, thereby realizing multiple driving and control of the four bidirectional analog switches 212.

[0080] The specific type of the quad bidirectional analog switch 212 can be configured based on actual needs and is not limited thereto. For example, the quad bidirectional analog switch 212 can utilize the CD4066 chip, a four-way bidirectional analog switch with low on-resistance and high isolation. The CD4066 chip controls the on / off switching of voltage signals, ensuring accurate and rapid signal transmission when needed.

[0081] The first filter 213 and the second filter 214 are used for filtering the signal to remove noise and interference and improve the quality of the signal. The specific types of the first filter 213 and the second filter 214 can be set according to actual needs and are not limited thereto.

[0082] The specific types of the first analog-to-digital converter 215 and the second analog-to-digital converter 216 can be set according to actual needs and are not limited to this. For example, the first analog-to-digital converter 215 and the second analog-to-digital converter 216 can use AD574 chips. The AD574 chip is a twelve-bit successive approximation analog-to-digital converter that converts analog signals into digital signals and transmits them to the control module 3 for subsequent digital processing.

[0083] like Figure 4 As shown, in some embodiments, the second sampling unit 22 includes: a twentieth resistor R20, a twenty-first resistor R21, a first operational amplifier OP1, a second operational amplifier OP2, a twenty-second resistor R22, and a thirteenth capacitor C13; wherein the first input terminal of the first operational amplifier OP1 is connected to the first end of the twentieth resistor R20, the second input terminal of the first operational amplifier OP1 is connected to the second end of the twentieth resistor R20, the first compensation terminal of the first operational amplifier OP1 is connected to the first end of the sampling resistor Rb, the second compensation terminal of the first operational amplifier OP1 is grounded, and the power supply terminal of the first operational amplifier OP1 is connected to the power supply terminal of the first power supply.

[0084] A reference voltage is input to a first input terminal of the second operational amplifier OP2, a second input terminal of the second operational amplifier OP2 is connected to a first terminal of a twenty-first resistor R21, a second terminal of the twenty-first resistor R21 is connected to a reference terminal of the first operational amplifier OP1, and a power supply terminal of the second operational amplifier OP2 is connected to a power supply terminal of a second power supply.

[0085] A first end of the twenty-second resistor R22 is connected to the output end of the first operational amplifier OP1, a second end of the twenty-second resistor R22 is connected to the input end of the control module 3, a first end of the thirteenth capacitor C13 is connected to the second end of the twenty-second resistor R22, and a second end of the thirteenth capacitor C13 is grounded.

[0086] It can be understood that, through the cooperation of the twentieth resistor R20, the twenty-first resistor R21, the first operational amplifier OP1 and the second operational amplifier OP2, the voltage at the sampling resistor Rb can be amplified according to the set ratio. At the same time, through the cooperation of the twenty-second resistor R22 and the thirteenth capacitor C13, the amplified voltage signal is filtered and output to the control module 3, so that the control module 3 can obtain the current and voltage of the device under test Rx according to the current and voltage of the reference path and the current and voltage of the sampling resistor Rb, thereby realizing accurate testing of the insulation resistance of the device under test Rx.

[0087] It should be noted that the specific resistance values of the twentieth resistor R20, the twenty-first resistor R21 and the twenty-second resistor R22 can be set according to actual needs and are not limited thereto.

[0088] The specific capacitance value of the thirteenth capacitor C13 can be set according to actual needs and is not limited thereto.

[0089] The first operational amplifier OP1 is used to amplify the voltage at the sampling resistor Rb. The specific type of the first operational amplifier OP1 can be set according to actual needs and is not limited thereto. For example, the first operational amplifier OP1 can adopt an AD8421 chip.

[0090] The second operational amplifier OP2 is used to provide a reference voltage for the first operational amplifier OP1. The specific type of the second operational amplifier OP2 can be set according to actual needs and is not limited to this. For example, the second operational amplifier OP2 can adopt an OP1177 chip, which is a low input bias current operational amplifier.

[0091] like Figure 1 As shown, in some embodiments, the sampling module 2 further includes: a protection unit 23, which is connected in series between the first end of the sampling resistor Rb and the second end of the device under test Rx. The protection unit 23 is configured to disconnect the path between the sampling resistor Rb and the device under test Rx when the current in the test path exceeds a set threshold.

[0092] It is understandable that when the current in the test path exceeds a set threshold, the protection unit 23 can disconnect the path between the sampling resistor Rb and the device under test Rx, thereby protecting the sampling module 2, the control module 3 and other circuits.

[0093] It should be noted that the specific type of the protection unit 23 can be set according to actual needs and is not limited thereto. For example, the protection unit 23 can adopt a TS5A3359 chip.

[0094] like Figure 1 As shown, in some embodiments, the control module 3 includes: a single-chip microcomputer 31 and an industrial computer 32; wherein the communication terminal of the single-chip microcomputer 31 is connected to the communication terminal of the voltage generating module 1 and the communication terminal of the sampling module 2 respectively, and the single-chip microcomputer 31 is used to output a first control signal and a second control signal, so that the voltage generating module 1 outputs different levels of negative polarity DC voltage according to the first control signal, and the sampling module 2 collects the current and voltage of the device under test Rx according to the second control signal.

[0095] The communication terminal of the industrial computer 32 is connected to the communication terminal of the single chip computer 31. The industrial computer 32 is used to generate a current-time curve and a current-voltage curve according to the current and voltage of the device under test Rx, and generate a test report according to the current-time curve and the current-voltage curve.

[0096] It can be understood that since the communication end of the single-chip microcomputer 31 is respectively connected to the communication end of the voltage generating module 1 and the communication end of the sampling module 2, the single-chip microcomputer 31 can output a first control signal to the voltage generating module 1 and a second control signal to the sampling module 2, so that the voltage generating module 1 can output different levels of negative polarity DC voltage according to the first control signal, and the sampling module 2 can collect the current and voltage of the device under test Rx according to the second control signal. At the same time, since the communication end of the industrial computer 32 is connected to the communication end of the single-chip microcomputer 31, the industrial computer 32 can generate a current-time curve and a current-voltage curve according to the current and voltage of the device under test Rx, and generate a test report according to the current-time curve and the current-voltage curve, thereby realizing the test of the insulation resistance of the device under test Rx.

[0097] It should be noted that the specific type of the single chip microcomputer 31 can be set according to actual needs and is not limited to this. For example, the single chip microcomputer 31 can adopt an stm32 chip.

[0098] The specific type of the industrial computer 32 can be set according to actual needs and is not limited thereto. For example, the industrial computer 32 can be a computer.

[0099] The 232 serial port communication can be used between the single chip microcomputer 31 and the industrial computer 32 , the industrial computer 32 sends control instructions to the single chip microcomputer 31 , and the single chip microcomputer 31 sends the current and voltage signals of the device under test Rx to the industrial computer 32 .

[0100] The control module 3 can also be provided with a wireless network card module, which can be used to transmit data wirelessly through radio frequency identification technology. Radio waves are sent and received through a built-in antenna. The wireless network card module encodes the data in the computer into radio signals for transmission, and at the same time receives radio signals from other devices and decodes them back into original data. Thus, the wireless network card module can automatically read relevant information of the device under test Rx when the test device is close to the device under test Rx, so as to select appropriate test parameters.

[0101] At the same time, the control module 3 can also use the temperature measurement module to obtain the temperature of the device under test Rx. The specific type of the temperature measurement module can be set according to actual needs and is not limited to this. For example, the temperature measurement module can use a DHT22 chip.

[0102] It should be noted that, in the description of this disclosure, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. In addition, in the description of this disclosure, unless otherwise specified, "plurality" means two or more.

[0103] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present disclosure includes additional implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present disclosure belong.

[0104] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0105] Although the embodiments of the present disclosure have been shown and described above, it is understood that the above embodiments are illustrative and are not to be construed as limitations on the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

Claims

1. An insulation resistance testing device, characterized in that: include: a voltage generating module, wherein a power supply terminal of the voltage generating module is connected to a power supply terminal of a DC power supply, and the power supply terminal of the voltage generating module is connected to a first terminal of the device under test; a sampling module, wherein a sampling end of the sampling module is connected to the second end of the device under test; a control module, wherein a communication terminal of the control module is respectively connected to a communication terminal of the voltage generating module and a communication terminal of the sampling module, the control module is configured to output a first control signal and a second control signal to cause the voltage generating module to output negative polarity DC voltages of different levels according to the first control signal, and to cause the sampling module to continuously collect the current and voltage of the device under test according to the second control signal, and the control module is further configured to generate a test report based on the current and voltage of the device under test; The sampling module includes: a reference resistor, a sampling resistor, a first sampling unit and a second sampling unit, wherein the second sampling unit includes: a twentieth resistor, a twenty-first resistor, a first operational amplifier, a second operational amplifier, a twenty-second resistor and a thirteenth capacitor; Wherein, the first input terminal of the first operational amplifier is connected to the first terminal of the twentieth resistor, the second input terminal of the first operational amplifier is connected to the second terminal of the twentieth resistor, the first compensation terminal of the first operational amplifier is connected to the first terminal of the sampling resistor, the second compensation terminal of the first operational amplifier is grounded, and the power supply terminal of the first operational amplifier is connected to the power supply terminal of the first power supply; A reference voltage is input to a first input terminal of the second operational amplifier, a second input terminal of the second operational amplifier is connected to a first terminal of a twenty-first resistor, a second terminal of the twenty-first resistor is connected to a reference terminal of the first operational amplifier, and a power supply terminal of the second operational amplifier is connected to a power supply terminal of a second power supply; The first end of the twenty-second resistor is connected to the output end of the first operational amplifier, the second end of the twenty-second resistor is connected to the input end of the control module, the first end of the thirteenth capacitor is connected to the second end of the twenty-second resistor, and the second end of the thirteenth capacitor is grounded.

2. The insulation resistance testing device according to claim 1, characterized in that: The voltage generating module includes: Switching unit, voltage doubling and rectifying unit, voltage stabilizing unit and pulse width modulation control unit; The power supply end of the switch unit is connected to the power supply end of the DC power supply, the power supply end of the switch unit is connected to the power supply end of the voltage doubler and rectifier unit, the power supply end of the voltage doubler and rectifier unit is connected to the first end of the device under test, and the input end of the voltage stabilizing unit is connected to the power supply end of the voltage doubler and rectifier unit; The input end of the pulse width modulation control unit is connected to the output end of the control module, the feedback end of the pulse width modulation control unit is connected to the output end of the voltage stabilizing unit, and the output end of the pulse width modulation control unit is connected to the input end of the switch unit. The pulse width modulation control unit is used to control the switch unit according to the first control signal so that the voltage doubler rectifier unit outputs negative polarity DC voltages of different levels, and the pulse width modulation control unit is also used to control the switch unit according to the feedback voltage of the voltage stabilizing unit to stabilize the negative polarity DC voltage output by the voltage doubler rectifier unit.

3. The insulation resistance testing device according to claim 2, characterized in that: The switch unit includes: A first resistor, a second resistor, a first capacitor, a first transistor, a second transistor, a transformer, a third resistor, a first switch, and a second switch; Wherein, a first end of the first resistor is connected to an emitter end of a first final-stage transistor of the pulse width modulation control unit, a second end of the first resistor is grounded, a first end of the second resistor is connected to an emitter end of a second final-stage transistor of the pulse width modulation control unit, a second end of the second resistor is grounded, a first end of the first capacitor is connected to a power supply end of the pulse width modulation control unit, and a second end of the first capacitor is grounded; The first transistor and the second transistor are respectively of NPN type, the base of the first transistor is connected to the first end of the second resistor, the collector of the first transistor is connected to the first end of the primary side of the transformer, the emitter of the first transistor is connected to the collector of the second transistor, the base of the second transistor is connected to the first end of the first resistor, and the emitter of the second transistor is connected to the second end of the primary side of the transformer; The secondary side of the transformer is connected to the power supply end of the voltage doubler rectifier unit; The first end of the third resistor is connected to the emitter of the second transistor, and the second end of the third resistor is connected to the collector end of the first final transistor and the collector end of the second transistor of the pulse width modulation control unit; The negative electrode of the DC power supply is grounded, the positive electrode of the DC power supply is connected to the first end of the first switch, the second end of the first switch is connected to the first end of the first capacitor, the first end of the second switch is connected to the second end of the first switch, and the second end of the first switch is connected to the third end of the primary side of the transformer.

4. The insulation resistance testing device according to claim 3, characterized in that: The voltage doubler and rectifier unit comprises: a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a first diode, a second diode, a third diode, and a fourth diode; Wherein, the first end of the second capacitor is connected to the first end of the secondary side of the transformer, the first end of the fourth capacitor is connected to the second end of the second capacitor, the first end of the third capacitor is connected to the second end of the secondary side of the transformer, the first end of the fifth capacitor is connected to the second end of the third capacitor, and the second end of the fifth capacitor is connected to the first end of the device under test; The anode of the first diode is connected to the second end of the second capacitor, the cathode of the first diode is connected to the first end of the third capacitor, the anode of the second diode is connected to the second end of the third capacitor, the cathode of the second diode is connected to the first end of the fourth capacitor, the anode of the third diode is connected to the second end of the fourth capacitor, the cathode of the third diode is connected to the first end of the fifth capacitor, the anode of the fourth diode is connected to the second end of the fifth capacitor, and the cathode of the fourth diode is connected to the second end of the fourth capacitor.

5. The insulation resistance testing device according to claim 3, characterized in that: The voltage stabilizing unit includes: a sixth capacitor, a fourth resistor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a third switch, a fourth switch, a fifth switch, and a sixth switch; Wherein, a first end of the sixth capacitor is connected to an inverting input end of a comparison amplifier of the pulse width modulation control unit, a second end of the sixth capacitor is connected to a common output end of the pulse width modulation control unit, a first end of the fourth resistor is connected to a first end of the sixth capacitor, a second end of the fourth resistor is connected to an output function control end of the pulse width modulation control unit, a first end of the seventh capacitor is connected to a first end of the fourth resistor, a second end of the seventh capacitor is connected to a second end of the fourth resistor, a first end of the eighth capacitor is connected to a first end of the seventh capacitor, and a second end of the eighth capacitor is connected to a second end of the seventh capacitor; The first end of the ninth capacitor is connected to the first end of the eighth capacitor, the first end of the tenth capacitor is connected to the second end of the ninth capacitor, the first end of the eleventh capacitor is connected to the second end of the tenth capacitor, the first end of the twelfth capacitor is connected to the second end of the eleventh capacitor, and the second end of the twelfth capacitor is connected to the first end of the device under test; a first end of the fifth resistor being connected to the first end of the ninth capacitor, a second end of the fifth resistor being connected to the second end of the ninth capacitor, a first end of the sixth resistor being connected to the first end of the tenth capacitor, a second end of the sixth resistor being connected to the second end of the tenth capacitor, a first end of the seventh resistor being connected to the first end of the eleventh capacitor, a second end of the seventh resistor being connected to the second end of the eleventh capacitor, a first end of the eighth resistor being connected to the first end of the twelfth capacitor, and a second end of the eighth resistor being connected to the second end of the twelfth capacitor; A first end of the ninth resistor is connected to a non-inverting input end of the comparison amplifier of the pulse width modulation control unit, a second end of the ninth resistor is grounded, a first end of the tenth resistor is connected to the second end of the eighth capacitor, a second end of the tenth resistor is connected to the first end of the third switch, a second end of the third switch is connected to the first end of the ninth resistor, a first end of the eleventh resistor is connected to the first end of the tenth resistor, a second end of the eleventh resistor is connected to the first end of the fourth switch, a second end of the fourth switch is connected to the second end of the third switch, a first end of the twelfth resistor is connected to the first end of the eleventh resistor, a second end of the twelfth resistor is connected to the first end of the fifth switch, a second end of the fifth switch is connected to the second end of the fourth switch, a first end of the thirteenth resistor is connected to the first end of the twelfth resistor, a second end of the thirteenth resistor is connected to the first end of the twelfth resistor, a second end of the thirteenth resistor is connected to the first end of the sixth switch, and a second end of the sixth switch is connected to the second end of the fifth switch.

6. The insulation resistance testing device according to claim 1, characterized in that: The first end of the reference resistor is connected to the power supply end of the voltage generating module to form a reference path, and the first end of the sampling resistor is connected to the second end of the device under test to form a test path; A first end of the first sampling unit is connected to the second end of the reference resistor, a second end of the first sampling unit is connected to the second end of the sampling resistor, and a third end of the first sampling unit is connected to the communication end of the control module. The first sampling unit is used to collect the current and voltage of the reference path; A first end of the second sampling unit is connected to a first end of the sampling resistor, a second end of the second sampling unit is connected to an input end of the control module, and the second sampling unit is used to collect the current and voltage of the test path; The control module is used to obtain the current and voltage of the device under test according to the current and voltage of the reference path and the current and voltage of the test path.

7. The insulation resistance testing device according to claim 6, characterized in that: The first sampling unit includes: a decoder, four bidirectional analog switches, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a first filter, a second filter, a first analog-to-digital converter, and a second analog-to-digital converter; The input end of the decoder is connected to the output end of the control module, and the output end of the decoder is connected to the control end of the four bidirectional analog switches; The first end of the fourteenth resistor is connected to the second end of the fifteenth resistor, the second end of the fourteenth resistor is connected to the second end of the reference resistor, and the first end of the fifteenth resistor is connected to the second end of the sampling resistor; a first end of the sixteenth resistor is connected to the first end of the four-way analog switch, a second end of the sixteenth resistor is connected to the first end of the fifteenth resistor, a first end of the seventeenth resistor is connected to the second end of the four-way analog switch, a second end of the seventeenth resistor is connected to the second end of the sixteenth resistor, a third end of the four-way analog switch is grounded, a first end of the eighteenth resistor is connected to the second end of the fourteenth resistor, a second end of the eighteenth resistor is connected to the first end of the nineteenth resistor, and a second end of the nineteenth resistor is grounded; The input end of the first filter is connected to the second end of the seventeenth resistor, the output end of the first filter is connected to the input end of the first analog-to-digital converter, and the output end of the first analog-to-digital converter is connected to the input end of the control module; The input end of the second filter is connected to the first end of the nineteenth resistor, the output end of the second filter is connected to the input end of the second analog-to-digital converter, and the output end of the second analog-to-digital converter is connected to the input end of the control module.

8. The insulation resistance testing device according to claim 6, characterized in that: The sampling module further includes: A protection unit is connected in series between the first end of the sampling resistor and the second end of the device under test, and is used to disconnect the path between the sampling resistor and the device under test when the current in the test path exceeds a set threshold.

9. The insulation resistance testing device according to any one of claims 1 to 8, characterized in that: The control module includes: Single chip microcomputer and industrial computer; The communication terminal of the single-chip microcomputer is connected to the communication terminal of the voltage generating module and the communication terminal of the sampling module respectively, and the single-chip microcomputer is used to output a first control signal and a second control signal, so that the voltage generating module outputs different levels of negative polarity DC voltage according to the first control signal, and the sampling module collects the current and voltage of the device under test according to the second control signal; The communication terminal of the industrial computer is connected to the communication terminal of the single chip computer. The industrial computer is used to generate a current-time curve and a current-voltage curve according to the current and voltage of the device under test, and generate the test report according to the current-time curve and the current-voltage curve.

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