High-voltage motor full-life state monitoring and analyzing device

Abstract

The invention relates to the technical field of motor life state monitoring, in particular to a high-voltage motor full-life state monitoring and analyzing device, which comprises an automatic constant-voltage output voltage regulating circuit, a measuring circuit and a protecting circuit, and the automatic constant-voltage output voltage regulating circuit, the measuring circuit and the protecting circuit comprise three groups of functional circuits. The functional circuit comprises a bus electrification judgment circuit, a residual voltage measurement circuit and a residual voltage discharge circuit; an insulation measurement voltage generation and measurement voltage sampling and bus electrification judgment circuit; the scheme is an on-line monitoring device, and functions cover measurement of insulation resistance, absorption ratio, polarization index, leakage current and the like. The safety protection performance has the functions of short-circuit measurement protection, bus high-voltage automatic judgment, sudden electrification protection for sudden electrification of the bus caused by misoperation during measurement, bus high-voltage residual voltage measurement and bus high-voltage residual voltage automatic discharge. And the sudden electrification protection function is used for sudden electrification of the bus caused by misoperation when the residual high voltage of the bus is discharged.

Description

Technical Field

[0001] The present invention relates to the technical field of motor life state monitoring, and in particular to a full life state monitoring and analysis device for a high-voltage motor. Background Art

[0002] At present, the insulation resistance, absorption ratio and polarization index measurement of high-voltage motors, generators and transformer coils all need to be measured manually after power outage, which is time-consuming, labor-intensive, inefficient and has safety hazards. In addition, the test data errors are large when manually tested with an ohmmeter, especially for the measurement of absorption ratio and polarization index. There are electronic insulation resistance testers on the market now, which have a simple measurement process and accurate data, but they still need to be manually operated after power outage and wire removal, and the efficiency improvement is not high. These are all offline measurements, and there are many products on the market.

[0003] There are also online monitoring devices for the insulation resistance of high-voltage motors, which mainly measure the insulation resistance. They have almost no function for measuring the absorption ratio and polarization index, and even if they do, the accuracy is very low; especially for measuring high-voltage motors and other equipment with relatively large capacitance to ground, the current online monitoring devices are inaccurate when measuring the insulation resistance, because all the measurement circuits of the online monitoring devices are connected in series with high-power coupling resistors. The high voltage during the test cannot directly charge the coil-to-ground capacitance. The voltage drop generated by the series coupling resistor causes the coil-to-ground capacitance to charge slowly, so that the insulation resistance is still changing when the test takes more than 10 minutes, and the insulation resistance cannot be accurately measured. The absorption ratio and polarization index are even more inaccurate, and the absorption ratio and polarization index are important judgment data for the insulation performance of high-voltage motors. Figure 2 It is the primary measurement circuit of the online monitoring device. The resistor R is a high voltage coupling resistor. There are two wiring modes: single resistor and three resistors. Figure 3 It is an equivalent circuit. It can be seen from the figure that the insulation test voltage DC is a DC constant voltage fixed voltage output. The charging current of the ground capacitor produces a voltage drop on the resistor R, causing the output test voltage to drop and change, hindering normal testing. Most field applications use a single resistor wiring method. The cost of three resistors is high, and the measurement effect is the same as that of a single resistor, so it is generally not used on site.

[0004] The insulation test voltage of the existing online insulation monitoring device is constant. The test voltage output by the coupling resistor is charged by the capacitance of the motor coil to the ground, which causes the actual test voltage of the motor coil to drop and change (the current generates a voltage drop on the coupling resistor), which hinders normal testing and causes inaccurate measurements of insulation resistance, absorption ratio, and polarization index. Before testing, the existing online insulation monitoring device can only determine whether the busbar is de-energized based on the auxiliary contacts of the high-voltage circuit breaker. It cannot actively measure whether the busbar connected to the coupling resistor is energized or whether there is residual voltage. Moreover, it cannot determine whether the busbar will suddenly become energized during testing, which poses a safety hazard.

[0005] The difference between the offline tester and the online monitoring device for high-voltage motor insulation resistance lies mainly in the working method. The offline tester is in a closed and stored state when not testing and is only used when testing is needed; the online monitoring device is usually connected to the high-voltage bus and is always subjected to the high voltage on the bus. The insulation resistance can only be monitored when the bus is powered off. Therefore, the reliability of the online monitoring device must be very high and cannot affect the performance and safety of the power grid.

[0006] For this purpose, a full life cycle status monitoring and analysis device for high voltage motors is proposed. Summary of the invention

[0007] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a high-voltage motor full-life status monitoring and analysis device.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions: A high-voltage motor full-life state monitoring and analysis device includes a voltage adjustment circuit, a measurement circuit, and a protection circuit for automatic constant voltage output. The voltage adjustment circuit, the measurement circuit, and the protection circuit for automatic constant voltage output include three groups of functional circuits, which are: Busbar live judgment, residual voltage measurement, residual voltage discharge circuit; Insulation measurement voltage generation and measurement voltage sampling, busbar live judgment circuit; Insulation measurement current sampling, measurement voltage output automatic adjustment circuit; The busbar is charged and the residual voltage is measured. The residual voltage discharge circuit includes a high-power high-voltage coupling resistor R1 connected to the high-voltage busbar, a high-voltage relay S1, current-limiting resistors R7 and R9, a sampling resistor R8, voltage-stabilizing diodes D5 and D6, an AC optical coupler U3, and a pull-up resistor R10; The insulation measurement voltage generation and measurement voltage sampling, busbar live judgment circuit includes a high-power high-voltage coupling resistor R1 connected to the high-voltage busbar, a high-voltage relay S2, current limiting resistors R2, R4, a sampling resistor R3, high-voltage diodes D1, D2, an adjustable high-voltage power supply U1, a voltage regulator diode D3, a diode D4, a DC optical coupler U2, and a pull-up resistor R5; The insulation measurement current sampling and measurement voltage output automatic adjustment circuit includes a sampling resistor R6, current limiting resistors R10, R11, R13, R14, pull-up resistors R15, R16, a gain resistor R12, an operational amplifier U4, high-speed analog-to-digital conversion chips U5, U6, a high-speed digital-to-analog conversion chip U7, and a central processing chip U8.

[0009] Preferably, the busbar is charged and the residual voltage is measured. The high-voltage relay S1 of the residual voltage discharge circuit is closed before the insulation test, and the coupling resistor R1 transmits the voltage of the high-voltage busbar to the current limiting resistors R7, R9, the sampling resistor R8, the voltage-stabilizing diodes D5, D6, and the input end of the AC optocoupler U3; The AC optocoupler U3 can also be replaced by a DC optocoupler. The AC optocoupler can output the positive and negative half-cycle signals of the AC voltage as pulse signals, and the central processing unit determines whether the bus is energized faster. The DC optocoupler can only output the positive or negative half-cycle signals of the AC signal, and the processor determines whether the bus is energized slower than the AC optocoupler.

[0010] Preferably, the insulation measurement voltage is generated and the measurement voltage is sampled, the busbar is not energized before the insulation test, the busbar residual voltage discharge is completed, the high-voltage relay S1 is disconnected, the high-voltage relay S2 is closed, the adjustable high-voltage power supply U1 is connected to the power relay S3, and U1 outputs a DC test voltage, which is output to the high-voltage busbar through the high-voltage diode D1, the high-voltage relay S2, and the coupling resistor R1; The DC test voltage passes through the current limiting resistor R2 and the sampling resistor R3; the OUT3 output signal of the sampling resistor R3 is collected by the analog-to-digital conversion signal to determine the DC test voltage value, which is used as the calculation data of the insulation resistance; since the insulation test output voltage is a negative voltage, the high-voltage diode D2 is reversely cut off and no current passes, thereby reducing unnecessary current loss of the adjustable high-voltage power supply U1.

[0011] Preferably, the insulation measurement current sampling and measurement voltage output automatic adjustment circuit generates a voltage on the sampling resistor R6 during insulation measurement, and the voltage is input into the operational amplifier U4 through the current limiting resistors R10 and R11. The output signal OUT5 of the operational amplifier U4 is collected by the analog-to-digital conversion chip U5, and the current value of the DC test loop can be determined; the voltage signal OUT3 of the resistor R3 is collected by the analog-to-digital conversion chip U6, and the voltage value of the DC test voltage can be determined; the central processing chip U8 calculates the sampling values ​​of the analog-to-digital conversion chips U5 and U6 to obtain the insulation resistance value and the voltage value output by the high-voltage coupling resistor in this period, and sends the high-voltage output voltage control level signal value that needs to be adjusted to the digital-to-analog conversion chip U7. The adjusted voltage value output by U7 is input into Vadj of the adjustable high-voltage power supply U1, and the test voltage output of the adjustable high-voltage power supply U1 is controlled, so that the insulation test voltage output by the coupling resistor R1 to the bus is constant within the measurement standard range; the above adjustment process is a high-speed cycle adjustment process.

[0012] Preferably, the functional circuit is also equipped with an analog-to-digital conversion circuit, an input pulse signal sampling circuit, a central processing control circuit, a communication circuit, a power supply voltage stabilization circuit, and a three-phase leakage current measurement.

[0013] Preferably, the three-phase high-voltage motor in the functional circuit is connected in a triangle connection method, and only one high-voltage coupling resistor is needed to connect any one-phase bus; R1 is a high-power high-voltage coupling resistor, connected to any one-phase high-voltage bus.

[0014] The beneficial effects of the present invention are: Before the insulation test, this solution will determine whether the busbar connected to the coupling resistor is powered off. If not, the insulation measurement will be terminated. If the busbar is powered off, the insulation monitoring device will measure whether there is residual voltage on the busbar connected to the coupling resistor, and can measure the residual voltage. If the residual voltage does not reach a safe value, the residual voltage value will be monitored while discharging, and insulation measurement will not be allowed until the residual voltage drops to a safe voltage. While the residual voltage is discharging, it can effectively determine the situation where the busbar is powered on due to misoperation. Once it is found that the busbar is energized, the insulation measurement will be stopped immediately and the discharge circuit will be disconnected.

[0015] During the insulation test, this solution will automatically adjust the voltage at the output end of the coupling resistor according to the size of the insulation measurement loop current, so that the insulation test voltage is constant within the measurement standard range. During the insulation test, it can effectively determine the situation where the busbar is energized due to misoperation. Once the busbar is found to be energized, the insulation measurement will be stopped immediately and the measurement loop will be disconnected.

[0016] After the insulation measurement is completed, this solution will automatically measure the bus residual voltage and automatically discharge until the residual voltage is within a safe range, then disconnect all test circuits and the insulation test is completed.

[0017] This solution can set the corresponding test voltage for different voltage test levels.

[0018] This solution is an online monitoring device, and its functions include insulation resistance, absorption ratio, polarization index, leakage current, etc. In terms of safety protection, it has the following functions: short circuit protection, automatic judgment of bus high voltage, sudden live protection when the bus is suddenly electrified due to misoperation during measurement, bus high voltage residual voltage measurement, automatic discharge of bus high voltage residual voltage, sudden live protection when the bus is suddenly electrified due to misoperation during discharge of bus high voltage residual voltage, etc. It can also set the corresponding test voltage for different voltage levels; The device can accurately measure the insulation resistance, absorption ratio, polarization index, leakage current and other parameters of large high-voltage motors, generators, and transformer coils under the condition of large capacitance to the ground. It has a high- and low-voltage separate installation structure and good safety protection performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the single-pole split structure of the high-voltage motor full-life condition monitoring and analysis device in the present invention; Figure 2 Two schematic diagrams of the first existing insulation test primary structure are shown; Figure 3 2 schematic diagrams of the first existing insulation test equivalent circuit; Figure 4 It is a schematic diagram of the single-pole split functional structure of the high-voltage motor full-life condition monitoring and analysis device of the present invention; Figure 5 It is a schematic diagram of the overall circuit principle of the high-voltage motor full-life status monitoring and analysis device of the present invention; Figure 6 for Figure 5 In the middle A area, there is a schematic diagram of the circuit principle of the busbar live judgment, residual voltage measurement, and residual voltage discharge circuit; Figure 7 for Figure 5 In the middle B area, there is a schematic diagram of the circuit principle of the insulation measurement voltage generation and measurement voltage sampling, and the busbar live judgment circuit; Figure 8 for Figure 5 In the middle C area, the circuit principle diagram of the upper part of the insulation measurement current sampling and measurement voltage output automatic adjustment circuit; Fig. 9 for Figure 5 In the middle C area, the circuit principle diagram of the lower part of the insulation measurement current sampling and measurement voltage output automatic adjustment circuit. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0021] Embodiment: A high-voltage motor life-cycle status monitoring and analysis device includes a voltage adjustment circuit, a measurement circuit, and a protection circuit for automatic constant voltage output. The voltage adjustment circuit, the measurement circuit, and the protection circuit for automatic constant voltage output include three groups of functional circuits, which are: Busbar live judgment, residual voltage measurement, residual voltage discharge circuit; Insulation measurement voltage generation and measurement voltage sampling, busbar live judgment circuit; Insulation measurement current sampling, measurement voltage output automatic adjustment circuit; Busbar live judgment, residual voltage measurement, residual voltage discharge circuit includes high-power high-voltage coupling resistor R1 connected to the high-voltage busbar, high-voltage relay S1, current limiting resistors R7, R9, sampling resistor R8, voltage stabilizing diodes D5, D6, AC optocoupler U3, pull-up resistor R10; Insulation measurement voltage generation and measurement voltage sampling, busbar live judgment circuit includes a high-power high-voltage coupling resistor R1 connected to the high-voltage busbar, a high-voltage relay S2, current-limiting resistors R2 and R4, a sampling resistor R3, high-voltage diodes D1 and D2, an adjustable high-voltage power supply U1, a voltage-stabilizing diode D3, a diode D4, a DC optocoupler U2, and a pull-up resistor R5; The insulation measurement current sampling and measurement voltage output automatic adjustment circuit includes a sampling resistor R6, current limiting resistors R10, R11, R13, R14, pull-up resistors R15, R16, gain resistor R12, operational amplifier U4, high-speed analog-to-digital conversion chips U5, U6, high-speed digital-to-analog conversion chip U7, and central processing chip U8.

[0022] Reference Figure 1 As shown, the single-pole split structure schematic diagram is Figure 2 The single resistor structure is basically the same as that of the embodiment. The installation structure in this scheme can also implement a three-resistance structure.

[0023] Reference Figure 4 As shown, the single-pole split functional structure diagram includes a specific implementation of the circuit of the present invention and a structural diagram of a product combined with peripheral supporting circuit function modules.

[0024] Reference Figure 5-6 ,This scheme implements a busbar live judgment, residual voltage measurement, and residual voltage discharge circuit. The circuit function is used before and after the insulation test. Before the insulation test, the high-voltage relay S1 is closed, and the coupling resistor R1 transmits the voltage of the high-voltage busbar to the current limiting resistors R7, R9, the sampling resistor R8, the voltage-stabilizing diodes D5, D6, and the input end of the AC optocoupler U3; If the high-voltage bus is energized at this time, the voltage-stabilizing diodes D5 and D6 are used to protect the input end of the AC optocoupler U3 and the OUT2 output end circuit of the sampling resistor R8 from being damaged by the input overvoltage. The AC voltage passes through the current-limiting resistor R9 to light up the light-emitting diodes at the input end of the AC optocoupler U3 in turn. The output end OUT1 of the AC optocoupler U3 outputs a pulse signal through the pull-up resistor R10. The central processor receives the pulse signal output by OUT1 and can determine whether the bus is energized. If the bus is energized, the high-voltage relay S1 is immediately disconnected to stop the insulation test, and a signal is sent to the display to show that the high-voltage bus is energized and the insulation test cannot be performed. The AC optocoupler U3 can also be replaced by a DC optocoupler. The AC optocoupler can output the positive and negative half-cycle signals of the AC voltage as pulse signals. The central processor determines whether the bus is energized faster. The DC optocoupler can only output the positive or negative half-cycle signals of the AC signal. The processor determines whether the bus is energized slower than the AC optocoupler. If the optocoupler has no pulse output, the bus is not energized. The OUT2 output signal of the sampling resistor R8 can be collected by the analog-to-digital conversion signal to determine the residual voltage value of the bus. If the residual voltage value exceeds the standard, since the high-voltage coupling resistor R1, the current limiting resistor R7, the sampling resistor R8 and the high-voltage bus to the ground are a closed loop, as long as the high-voltage relay S1 is closed, it will be discharged. The OUT2 output signal of the sampling resistor R8 is always read by the central processor, and it can be determined whether the discharge is completed; if the bus is suddenly energized at this time, the output terminal OUT1 of the AC optocoupler U3 will immediately output a pulse signal, and the central processor will immediately disconnect the high-voltage relay S1 to terminate the insulation test. After the insulation test is completed, the high-voltage relay S2 is disconnected, and the high-voltage relay S1 is closed, and the above discharge process is repeated, and finally the entire insulation test is completed.

[0025] Reference Figure 7 This scheme implements an insulation measurement voltage generation and measurement voltage sampling, busbar live judgment circuit, in which high-voltage diodes D1 and D2 are used for reverse cutoff protection, voltage regulator diode D3 is used to protect the input end of DC optocoupler U2 from being damaged by input overvoltage, and diode D4 is used to protect the input end of DC optocoupler U2 from being damaged by reverse input overvoltage; Before the insulation test, the busbar is not energized and the residual voltage of the busbar is discharged. The high-voltage relay S1 is disconnected, the high-voltage relay S2 is closed, and the adjustable high-voltage power supply U1 is connected to the power supply relay S3. U1 outputs a DC test voltage, which is output to the high-voltage busbar through the high-voltage diode D1, the high-voltage relay S2, and the coupling resistor R1; The DC test voltage passes through the current limiting resistor R2 and the sampling resistor R3; the OUT3 output signal of the sampling resistor R3 can be collected by the analog-to-digital conversion signal to determine the DC test voltage value, which is used as the calculation data of the insulation resistance; because the insulation test output voltage is a negative voltage, the high-voltage diode D2 is reversely cut off, and no current passes, reducing the unnecessary current loss of the adjustable high-voltage power supply U1; If the bus is suddenly energized, the positive half-cycle voltage of the bus voltage will be limited by the voltage-limiting diode D3 through the high-voltage diode D2, and flow into the light-emitting diode of the DC optocoupler U2 through the current-limiting resistor R4. The output terminal OUT4 will immediately output a pulse signal through the pull-up resistor R5. The central processing unit can determine whether the bus is energized after receiving the pulse signal output by OUT4. If the bus is energized, the high-voltage relay S2 will be disconnected immediately, the power relay S3 of the adjustable high-voltage power supply U1 will be disconnected, and the insulation test will be stopped.

[0026] Reference Figure 8-9This scheme implements an insulation measurement current sampling and measurement voltage output automatic adjustment circuit. During insulation measurement, the test loop current generates a voltage on the sampling resistor R6, which is input into the operational amplifier U4 through the current limiting resistors R10 and R11. The output signal of the output terminal OUT5 of the operational amplifier U4 is collected by the analog-to-digital conversion chip U5, and the current value of the DC test loop can be determined, which is used as the calculation data of the insulation resistance; the voltage signal of the OUT3 of the resistor R3 is collected by the analog-to-digital conversion chip U6, and the voltage value of the DC test voltage can be determined, which is used as the calculation data of the insulation resistance and the output high-voltage test voltage. The central processing chip U8 calculates the sampling values ​​of the analog-to-digital conversion chips U5 and U6 to obtain the insulation resistance value and the voltage value output by the high-voltage coupling resistor during the period, and sends the high-voltage output voltage control level signal value that needs to be adjusted to the digital-to-analog conversion chip U7. The adjusted voltage value output by U7 is input into Vadj (adjustable control voltage input) of the adjustable high-voltage power supply U1 to control the test voltage output of the adjustable high-voltage power supply U1, so that the insulation test voltage output by the coupling resistor R1 to the busbar is constant within the measurement standard range; the above adjustment process is a high-speed cycle adjustment process; This function can also be adjusted for different test voltages; for example, some test voltages are 500V, some are 1KV, and so on. As long as the test voltage value is set, the central processing chip U8 adjusts the initial test output voltage of the digital-to-analog conversion chip U7 to achieve this function.

[0027] The functional circuit is also equipped with an analog-to-digital conversion circuit, an input pulse signal sampling circuit, a central processing control circuit, a communication circuit, a power supply voltage stabilization circuit, and a three-phase leakage current measurement.

[0028] The three-phase high-voltage motor in the functional circuit is connected in a triangle connection method, and only one high-voltage coupling resistor is needed to connect any phase bus; R1 is a high-power high-voltage coupling resistor, connected to any phase high-voltage bus.

[0029] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0030] The standard parts used in the present invention can all be purchased from the market, and special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, etc. in the prior art. The machinery, parts and equipment all adopt conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be described in detail here.

[0031] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A high-voltage motor full-life condition monitoring and analysis device, characterized in that: include: The voltage adjustment circuit, measurement circuit and protection circuit of the automatic constant voltage output include three groups of functional circuits, which are: Busbar live judgment, residual voltage measurement, residual voltage discharge circuit; Insulation measurement voltage generation and measurement voltage sampling, busbar live judgment circuit; Insulation measurement current sampling, measurement voltage output automatic adjustment circuit; The busbar is charged and the residual voltage is measured. The residual voltage discharge circuit includes a high-power high-voltage coupling resistor R1 connected to the high-voltage busbar, a high-voltage relay S1, current-limiting resistors R7 and R9, a sampling resistor R8, voltage-stabilizing diodes D5 and D6, an AC optical coupler U3, and a pull-up resistor R10; The insulation measurement voltage generation and measurement voltage sampling, busbar live judgment circuit includes a high-power high-voltage coupling resistor R1 connected to the high-voltage busbar, a high-voltage relay S2, current limiting resistors R2, R4, a sampling resistor R3, high-voltage diodes D1, D2, an adjustable high-voltage power supply U1, a voltage regulator diode D3, a diode D4, a DC optical coupler U2, and a pull-up resistor R5; The insulation measurement current sampling and measurement voltage output automatic adjustment circuit includes a sampling resistor R6, current limiting resistors R10, R11, R13, R14, pull-up resistors R15, R16, a gain resistor R12, an operational amplifier U4, high-speed analog-to-digital conversion chips U5, U6, a high-speed digital-to-analog conversion chip U7, and a central processing chip U8.

2. The high-voltage motor life cycle status monitoring and analysis device according to claim 1 is characterized in that: The busbar is charged and the residual voltage is measured. The residual voltage discharge circuit is closed before the insulation test. The high-voltage relay S1 is closed, and the coupling resistor R1 transmits the voltage of the high-voltage busbar to the current limiting resistors R7, R9, the sampling resistor R8, the voltage-stabilizing diodes D5, D6, and the input end of the AC optocoupler U3; The AC optocoupler U3 can also be replaced by a DC optocoupler. The AC optocoupler can output the positive and negative half-cycle signals of the AC voltage as pulse signals, and the central processing unit determines whether the bus is energized faster. The DC optocoupler can only output the positive or negative half-cycle signals of the AC signal, and the processor determines whether the bus is energized slower than the AC optocoupler.

3. The high-voltage motor life cycle status monitoring and analysis device according to claim 1 is characterized in that: The insulation measurement voltage is generated and the measurement voltage is sampled. The busbar is not energized before the insulation test and the residual voltage discharge of the busbar is completed. The high-voltage relay S1 is disconnected, the high-voltage relay S2 is closed, and the adjustable high-voltage power supply U1 is connected to the power relay S3. U1 outputs a DC test voltage, which is output to the high-voltage busbar through the high-voltage diode D1, the high-voltage relay S2, and the coupling resistor R1; The DC test voltage passes through the current limiting resistor R2 and the sampling resistor R3; the OUT3 output signal of the sampling resistor R3 is collected by the analog-to-digital conversion signal to determine the DC test voltage value, which is used as the calculation data of the insulation resistance; since the insulation test output voltage is a negative voltage, the high-voltage diode D2 is reversely cut off and no current passes, thereby reducing unnecessary current loss of the adjustable high-voltage power supply U1.

4. The high-voltage motor life cycle status monitoring and analysis device according to claim 1 is characterized in that: The insulation measurement current sampling and measurement voltage output automatic adjustment circuit generates a voltage on the sampling resistor R6 during insulation measurement. The voltage is input into the operational amplifier U4 through the current limiting resistors R10 and R11. The output signal of the output terminal OUT5 of the operational amplifier U4 is collected by the analog-to-digital conversion chip U5, and the current value of the DC test circuit can be determined; the voltage signal OUT3 of the resistor R3 is collected by the analog-to-digital conversion chip U6, and the voltage value of the DC test voltage can be determined; the central processing chip U8 calculates the sampling values ​​of the analog-to-digital conversion chips U5 and U6 to obtain the insulation resistance value and the voltage value output by the high-voltage coupling resistor in the period, and sends the high-voltage output voltage control level signal value that needs to be adjusted to the digital-to-analog conversion chip U7. The adjusted voltage value output by U7 is input into Vadj of the adjustable high-voltage power supply U1, and the test voltage output of the adjustable high-voltage power supply U1 is controlled, so that the insulation test voltage output by the coupling resistor R1 to the bus is constant within the measurement standard range; the above adjustment process is a high-speed cycle adjustment process.

5. The high-voltage motor life cycle status monitoring and analysis device according to claim 1 is characterized in that: The functional circuit is also equipped with an analog-to-digital conversion circuit, an input pulse signal sampling circuit, a central processing control circuit, a communication circuit, a power supply voltage stabilization circuit, and a three-phase leakage current measurement.

6. The high-voltage motor life cycle status monitoring and analysis device according to claim 1 is characterized in that: The three-phase high-voltage motor in the functional circuit is connected in a triangle manner, and only one high-voltage coupling resistor is needed to connect any one-phase bus; R1 is a high-power high-voltage coupling resistor, connected to any one-phase high-voltage bus.

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