Motor insulation fault detection method, device, computer equipment and storage medium

Abstract

The present application relates to a motor insulation fault detection method, device, computer equipment, and storage medium. The method includes: generating a DC excitation voltage and an AC excitation voltage based on a power-on signal of a frequency converter; applying the DC excitation voltage and the AC excitation voltage to any two phases of the motor to be tested, respectively, to obtain test response data of any two phases of the motor to be tested; calculating an insulation degradation index based on the test response data; and determining the insulation state of the motor to be tested based on the insulation degradation index and a preset index threshold. The present application does not require the provision of an additional fault detection device. By automatically applying a composite AC / DC excitation voltage to the motor through the frequency converter, the motor can effectively simplify the detection process of the motor insulation fault and improve detection efficiency.

Description

Technical Field

[0001] The present application relates to the technical field of motor fault detection, and in particular to a motor insulation fault detection method, device, computer equipment, and storage medium. Background Art

[0002] Stator interturn insulation failure is a typical motor failure mode and the root cause of serious faults such as phase-to-phase short circuits and phase grounding. Detecting stator interturn insulation failures is crucial to detect and warn of them early and prevent them from causing unexpected motor downtime.

[0003] Currently, stator interturn insulation fault detection is categorized as offline and online. Online detection methods typically rely on specific fault symptoms. During motor operation, they collect electrical, thermal, vibration, and acoustic signals, extract features using time-frequency analysis, and classify and determine the fault type using artificial intelligence algorithms. Although online diagnostic methods can detect faults in real time, they are susceptible to operating conditions and rely heavily on data samples, leaving many challenges unresolved in practical applications. While offline detection methods lack real-time performance, they offer more accurate results because the motor is stationary when offline and unaffected by operating conditions. Currently, these methods are the primary means of monitoring motor insulation faults.

[0004] Common offline detection methods for motor insulation faults include insulation resistance testing, polarization index testing, and partial discharge testing. These tests require isolating the motor from operating mode, disconnecting existing connections, and then inserting specialized test instruments, making the testing process cumbersome and difficult to implement. Summary of the Invention

[0005] Based on this, it is necessary to provide a motor insulation fault detection method, device, computer equipment and storage medium that can simplify the testing process to address the above technical problems.

[0006] In a first aspect, the present application provides a method for detecting insulation faults in a motor, the method comprising:

[0007] Generate DC excitation voltage and AC excitation voltage according to the power-on signal of the inverter;

[0008] Applying the DC excitation voltage and the AC excitation voltage to any two phases of the motor to be tested respectively to obtain test response data of any two phases of the motor to be tested;

[0009] Calculating an insulation degradation index based on the test response data;

[0010] The insulation state of the motor to be tested is determined according to the insulation degradation index and a preset index threshold.

[0011] In one embodiment, the method further comprises:

[0012] Calculating a reference equivalent resistance and a reference equivalent inductance between any two phases of the motor to be tested according to the test response data;

[0013] Calculating the equivalent resistance change rate and the equivalent inductance change rate between any two phases of the motor to be tested according to the initial equivalent resistance, the initial equivalent inductance, the reference equivalent resistance, and the reference equivalent inductance between any two phases of the motor to be tested;

[0014] The insulation fault position of the motor to be tested is determined according to the equivalent resistance change rate and the equivalent inductance change rate between any two phases of the motor to be tested.

[0015] In one embodiment, the equivalent resistance change rate between any two phases of the motor to be tested includes a first equivalent resistance change rate, a second equivalent resistance change rate, and a third equivalent resistance change rate; the equivalent inductance change rate between any two phases of the motor to be tested includes a first equivalent inductance change rate, a second equivalent inductance change rate, and a third equivalent inductance change rate; and determining the insulation fault position of the motor to be tested based on the equivalent resistance change rate and the equivalent inductance change rate between any two phases of the motor to be tested includes:

[0016] sorting the first equivalent resistance change rate, the second equivalent resistance change rate, and the third equivalent resistance change rate, and sorting the first equivalent inductance change rate, the second equivalent inductance change rate, and the third equivalent inductance change rate;

[0017] If the first equivalent resistance change rate is the smallest or the first equivalent inductance change rate is the smallest, determining that the insulation fault position of the motor to be tested is phase A;

[0018] If the second equivalent resistance change rate is the smallest or the second equivalent inductance change rate is the smallest, determining that the insulation fault position of the motor to be tested is phase B;

[0019] If the third equivalent resistance change rate is the smallest or the third equivalent inductance change rate is the smallest, it is determined that the insulation fault position of the motor to be tested is phase C.

[0020] In one embodiment, the step of applying the DC excitation voltage and the AC excitation voltage to any two-phase bridge arms of the motor to be tested to obtain test response data of any two-phase bridge arms of the motor to be tested includes:

[0021] Applying the DC excitation voltage and the AC excitation voltage to phases A and B of the motor to be tested to obtain test response data of phases A and B of the motor to be tested;

[0022] Applying the DC excitation voltage and the AC excitation voltage to phases A and C of the motor to be tested to obtain test response data of phases A and C of the motor to be tested;

[0023] The DC excitation voltage and the AC excitation voltage are applied to the B-phase and the C-phase of the motor to be tested to obtain test response data of the B-phase and the C-phase of the motor to be tested.

[0024] In one embodiment, the step of calculating the insulation degradation index based on the test response data includes:

[0025] Calculating a reference equivalent resistance and a reference equivalent inductance between any two phases of the motor to be tested according to the test response data;

[0026] The resistance insulation degradation index and the inductance insulation degradation index are calculated according to the reference equivalent resistance and the reference equivalent inductance between any two phases of the motor to be tested.

[0027] In one embodiment, the calculation formula of the resistance insulation degradation index is:

[0028]

[0029] Among them, FI R is the resistance insulation degradation index, is the reference equivalent resistance between phase A and phase B, is the reference equivalent resistance between phase B and phase C, is the reference equivalent resistance between phase C and phase A;

[0030] And / or, the calculation method of the inductor insulation degradation index includes:

[0031]

[0032] in, FI ΔL is the inductor insulation degradation index, is the initial equivalent inductance between phase A and phase B, is the initial equivalent inductance between phase B and phase C, is the initial equivalent inductance between phase C and phase A, is the reference equivalent inductance between phase A and phase B, is the reference equivalent inductance between phase B and phase C, is the reference equivalent inductance between phase C and phase A.

[0033] In one embodiment, determining the insulation state of the motor to be tested according to the insulation degradation index and a preset index threshold includes:

[0034] If the resistance insulation degradation index is greater than the first index threshold, or the inductance insulation degradation index is greater than the first index threshold, it is determined that the motor is in an insulation degradation state;

[0035] If the resistance insulation degradation index is greater than a second index threshold, or the inductance insulation degradation index is greater than the second index threshold, it is determined that the motor is in an insulation fault state, wherein the second index threshold is greater than the first index threshold.

[0036] In a second aspect, the present application further provides a motor insulation fault detection device, the device comprising:

[0037] A voltage generation module is used to generate a DC excitation voltage and an AC excitation voltage according to a power-on signal of the inverter;

[0038] A voltage application module, configured to apply the DC excitation voltage and the AC excitation voltage to any two phases of the motor to be tested, respectively, to obtain test response data of any two phases of the motor to be tested;

[0039] An index calculation module, configured to calculate an insulation degradation index based on the test response data;

[0040] A fault detection module is used to determine the insulation status of the motor to be tested according to the insulation degradation index and a preset index threshold.

[0041] In a third aspect, the present application further provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the motor insulation fault detection method described in the first aspect when executing the computer program.

[0042] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the motor insulation fault detection method described in the first aspect.

[0043] In summary, the present application proposes a motor insulation fault detection method, device, computer equipment and storage medium, the method comprising: generating a DC excitation voltage and an AC excitation voltage according to a power-on signal of a frequency converter; applying the DC excitation voltage and the AC excitation voltage to any two phases of the motor to be tested, respectively, to obtain test response data of any two phases of the motor to be tested; calculating an insulation degradation index according to the test response data; and determining the insulation state of the motor to be tested according to the insulation degradation index and a preset index threshold. The present application does not require the provision of an additional fault detection device, and automatically applies an AC / DC composite excitation voltage to the motor through the frequency converter, which can effectively simplify the detection process of the motor insulation fault and improve the detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 1 is a flow chart of a method for detecting motor insulation faults in one embodiment;

[0045] Figure 2 1 is a circuit diagram of a method for detecting motor insulation faults in one embodiment;

[0046] Figure 3 1 is a flow chart of a method for detecting motor insulation faults in another embodiment;

[0047] Figure 4 FIG1 is a flow chart of steps for determining an insulation fault location of a motor to be tested in one embodiment;

[0048] Figure 5 1 is a flow chart of steps for calculating an insulation degradation index in one embodiment;

[0049] Figure 6 A schematic flow chart of steps for determining the insulation status of a motor to be tested in one embodiment;

[0050] Figure 7 1. A schematic diagram of a module of a motor insulation fault detection device according to an embodiment;

[0051] Figure 8 FIG. 1 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0053] In one embodiment, Figure 1 As shown, a motor insulation fault detection method is provided, which is applied to Figure 2 The detection circuit in FIG is taken as an example to illustrate, which includes the following steps:

[0054] S101 , generating a DC excitation voltage and an AC excitation voltage according to a power-on signal of the inverter.

[0055] The motor insulation fault detection method proposed in this embodiment can be applied to AC motors driven by a frequency converter, such as asynchronous motors, permanent magnet synchronous motors, and the like.

[0056] In a specific embodiment, after being powered on, the frequency converter generates a frequency converter power-on signal to trigger an excitation signal generation program to generate corresponding DC excitation voltage signals and AC excitation voltage signals.

[0057] It should be noted that the excitation signal generation program can be run in a motor control device. This embodiment does not limit the type of the motor control device, and it can be adaptively replaced according to actual application scenarios.

[0058] Specifically, if Figure 2 As shown, the motor includes a corresponding PWM pulse signal module, an inverter module and a three-phase power supply module, wherein the inverter module is composed of a plurality of power tube devices. This embodiment does not limit the specific structure of the inverter module, and can adopt the following structure: Figure 2 The circuit consists of six power tubes: the upper power tube for phase A, the lower power tube for phase A, the upper power tube for phase B, the lower power tube for phase B, the upper power tube for phase C, and the lower power tube for phase C. In actual applications, for the same phase bridge arm, the PWM pulse signals of the upper and lower power tubes complement each other.

[0059] In a specific embodiment, pulse blocking can be performed on the upper power tube and the lower power tube of any phase bridge arm to achieve application of a DC excitation voltage signal and an AC excitation voltage signal to the other phase bridge arm.

[0060] Specifically, the motor control device can generate corresponding voltage instructions based on the power-on signal of the inverter, so as to generate corresponding PWM pulse signals through the pulse width modulation link in the motor control algorithm, and drive the power tube devices on the corresponding phase bridge arms to generate corresponding DC excitation voltage signals and AC excitation voltage signals.

[0061] Taking the generation of PWM pulse signals on phases A and B as an example, the specific value of the voltage command can be calculated using the following formula:

[0062]

[0063] in, is the PWM pulse signal on phase A, is the PWM pulse signal on phase B, ΔU dc is the DC excitation voltage signal, ΔU ac ×cos(2πft) is the AC excitation voltage signal, f is the motor frequency, and the PWM pulse signal on phase A and phase B is u AB =u A -u B =ΔU dc +ΔU ac ×cos(2πft).

[0064] In a specific embodiment, ΔU dc The voltage value can be 2V, ΔU ac The amplitude can be 5V, and the motor frequency f is greater than 200Hz.

[0065] S102 , applying a DC excitation voltage and an AC excitation voltage to any two phases of the motor to be tested, respectively, to obtain test response data of any two phases of the motor to be tested.

[0066] Specifically, by sequentially blocking the upper and lower power transistors on different phase bridge arms, DC and AC excitation voltages can be applied to any two phases of the motor under test. When a composite excitation signal of DC and AC voltages is applied to the motor's three-phase circuit, the motor will generate corresponding DC and AC current responses.

[0067] The test response data includes direct current response data and alternating current response data.

[0068] For example, when applying DC excitation voltage and AC excitation voltage to phase A and phase B of the motor, the inverter collects the test response data of the motor. A |=|i B |=|i AB |. For phase A current i A The average value can be used to obtain the DC current response ΔI dc , using the formula Δi ac =i A -ΔI dc Calculate the AC current response Δi ac .

[0069] Specifically, after obtaining the test response data of any two phases of the motor to be tested, other mathematical processing methods can be further used to process the test response data to obtain test-related data. For example, the AC current response Δi ac Fourier analysis can be used to obtain the AC current amplitude ΔI ac .

[0070] In one embodiment, applying a DC excitation voltage and an AC excitation voltage to any two-phase bridge arms of the motor to be tested respectively to obtain test response data of any two-phase bridge arms of the motor to be tested includes:

[0071] Applying a DC excitation voltage and an AC excitation voltage to phases A and B of the motor to be tested to obtain test response data of phases A and B of the motor to be tested;

[0072] Applying a DC excitation voltage and an AC excitation voltage to phases A and C of the motor to be tested to obtain test response data of phases A and C of the motor to be tested;

[0073] Apply a DC excitation voltage and an AC excitation voltage to phases B and C of the motor to be tested to obtain test response data of phases B and C of the motor to be tested.

[0074] During the specific implementation process, the process of applying DC excitation voltage signals and AC excitation voltage signals in this embodiment requires testing phase A and phase B, phase B and phase C, and phase A and phase C respectively to obtain the corresponding test response data of phase A and phase B, phase B and phase C, and phase A and phase C.

[0075] It should be noted that the test order of testing phase A and phase B, phase B and phase C, and phase A and phase C can be adaptively replaced according to actual application needs, and this embodiment does not limit this.

[0076] S103: Calculate an insulation degradation index based on the test response data.

[0077] Specifically, the insulation degradation index in this embodiment includes a resistance insulation degradation index and an inductance insulation degradation index.

[0078] When calculating the insulation degradation index, intermediate data such as equivalent resistance and equivalent inductance are calculated based on the test response data, and then the intermediate data are used to further complete the calculation of the insulation degradation index.

[0079] S104: Determine the insulation status of the motor to be tested according to the insulation degradation index and a preset index threshold.

[0080] Specifically, a comparison is made between the insulation degradation index and a preset index threshold, and the insulation status of the motor to be tested is output based on the comparison result of the insulation degradation index and the preset index threshold. The insulation status of the motor to be tested includes an insulation degradation state and an insulation fault state.

[0081] In summary, this embodiment provides a method for detecting motor insulation faults. After the frequency converter is powered on, this embodiment generates corresponding DC excitation voltage signals and AC excitation voltage signals, and collects test response data of the motor by applying DC excitation voltage signals and AC excitation voltage signals to any two phases of the motor. Finally, the test response data is used to calculate the insulation degradation index, and the insulation status of the motor to be tested is determined based on the comparison result between the insulation degradation index and a preset index threshold. The motor insulation fault detection method provided by this embodiment does not require the use of complex detection instruments, and directly uses the existing structure in the motor to detect motor insulation faults. The detection is rapid and efficient, and can effectively monitor the insulation status of the motor to ensure motor safety.

[0082] In one embodiment, Figure 3 As shown, the motor insulation fault detection method further includes:

[0083] S201, calculating a reference equivalent resistance and a reference equivalent inductance between any two phases of the motor to be tested based on the test response data;

[0084] Specifically, taking the application of DC excitation voltage signal and AC excitation voltage signal to phase A and phase B as an example, the corresponding DC excitation voltage parameter ΔU can be obtained. dc , AC excitation voltage parameter ΔU ac , DC current response parameter ΔI dc And the AC current response parameter ΔI ac .

[0085] Using the formula Calculate the corresponding reference equivalent resistance between phase A and phase B and reference equivalent inductance

[0086] In a specific embodiment, the test response data includes the current response data between any two phases of the motor to be tested, and the reference equivalent resistance finally calculated includes and Reference inductance includes and

[0087] S202, calculating an equivalent resistance change rate and an equivalent inductance change rate between any two phases of the motor to be tested based on an initial equivalent resistance, an initial equivalent inductance, a reference equivalent resistance, and a reference equivalent inductance between any two phases of the motor to be tested;

[0088] In a specific embodiment, the equivalent resistance change rate between any two phases of the motor to be tested includes a first equivalent resistance change rate, a second equivalent resistance change rate and a third equivalent resistance change rate, and the equivalent inductance change rate between any two phases of the motor to be tested includes a first equivalent inductance change rate, a second equivalent inductance change rate and a third equivalent inductance change rate.

[0089] The first equivalent resistance change rate is the change rate of the equivalent resistance between phase A and phase B. The second equivalent resistance change rate is the change rate of the equivalent resistance between phases B and C. The third equivalent resistance change rate is the change rate of the equivalent resistance between phase C and phase A.

[0090] The first equivalent inductance change rate is the change rate of the equivalent inductance between phase A and phase B. The second equivalent inductance change rate is the change rate of the equivalent inductance between phases B and C. The third equivalent inductance change rate is the change rate of the equivalent inductance between phase C and phase A.

[0091] Specifically, the calculation formulas for the equivalent resistance change rate and the equivalent inductance change rate are:

[0092]

[0093] Where x is AB, BC or CA, R x0 is the initial equivalent resistance, R x is the reference equivalent resistance, L x0 is the initial equivalent inductance, L x is the reference equivalent inductance, is the equivalent resistance change rate, is the rate of change of equivalent inductance.

[0094] S203 , determining the insulation fault location of the motor to be tested according to the equivalent resistance change rate and the equivalent inductance change rate between any two phases of the motor to be tested.

[0095] Specifically, by comparing the calculated equivalent resistance change rates and equivalent inductance change rates, the insulation fault location of the motor to be tested can be accurately determined.

[0096] In one embodiment, Figure 4 As shown, S203 includes:

[0097] S301, sorting the first equivalent resistance change rate, the second equivalent resistance change rate, and the third equivalent resistance change rate, and sorting the first equivalent inductance change rate, the second equivalent inductance change rate, and the third equivalent inductance change rate;

[0098] S302: If the first equivalent resistance change rate is the smallest or the first equivalent inductance change rate is the smallest, it is determined that the insulation fault position of the motor to be tested is phase A;

[0099] S303: If the second equivalent resistance change rate is the smallest or the second equivalent inductance change rate is the smallest, it is determined that the insulation fault position of the motor to be tested is phase B;

[0100] S304: If the third equivalent resistance change rate is the smallest or the third equivalent inductance change rate is the smallest, it is determined that the insulation fault position of the motor to be tested is phase C.

[0101] In a specific embodiment, by comparing the change rates of each equivalent inductance and each equivalent resistance, the insulation fault location of the motor to be tested can be accurately determined, which can effectively assist personnel in repairing the fault of the motor to be tested and ensure the safety of the motor.

[0102] In one embodiment, Figure 5 As shown, step S103 includes:

[0103] Step S401, calculating a reference equivalent resistance and a reference equivalent inductance between any two phases of the motor to be tested based on the test response data;

[0104] Step S402 : calculating a resistance insulation degradation index and an inductance insulation degradation index according to a reference equivalent resistance and a reference equivalent inductance between any two phases of the motor to be tested.

[0105] In a specific embodiment, the reference equivalent resistance and the reference equivalent inductance are intermediate indicators for calculating the resistance insulation degradation index and the inductance insulation degradation index.

[0106] In one embodiment, the calculation formula of the resistance insulation degradation index is:

[0107]

[0108] Among them, FI R is the resistance insulation degradation index, is the reference equivalent resistance between phase A and phase B, is the reference equivalent resistance between phase B and phase C, is the reference equivalent resistance between phase C and phase A;

[0109] and / or, a method for calculating an inductor insulation degradation index, including:

[0110]

[0111] in, FI ΔL is the inductor insulation degradation index, is the initial equivalent inductance between phase A and phase B, is the initial equivalent inductance between phase B and phase C, is the initial equivalent inductance between phase C and phase A, is the reference equivalent inductance between phase A and phase B, is the reference equivalent inductance between phase B and phase C, is the reference equivalent inductance between phase C and phase A.

[0112] In one embodiment, Figure 6 As shown, step S104 includes:

[0113] S501, if the resistance insulation degradation index is greater than or equal to the first index threshold, or the inductance insulation degradation index is greater than or equal to the first index threshold, determine that the motor is in an insulation degradation state;

[0114] In a specific embodiment, the first indicator threshold value may be customized according to the needs of an actual application scenario. In this embodiment, the first indicator threshold value may be 1%.

[0115] When the resistance insulation degradation index FI R ≥1% or inductance insulation degradation index FI ΔL≥1%, it can be determined that the motor under test is in an insulation degradation state, and the degradation degree is 0.5 (FI R +FI ΔL ).

[0116] S502: If the resistance insulation degradation index is greater than or equal to a second index threshold, or the inductance insulation degradation index is greater than or equal to a second index threshold, determine that the motor is in an insulation fault state, wherein the second index threshold is greater than the first index threshold.

[0117] In a specific embodiment, the second indicator threshold value may be customized according to the needs of an actual application scenario. In this embodiment, the second indicator threshold value may be 5%.

[0118] When the resistance insulation degradation index FI R ≥5% or inductance insulation degradation index FI ΔL ≥5%, it can be determined that the motor to be tested is in an insulation fault state.

[0119] In summary, this embodiment proposes a motor insulation fault detection method that eliminates the need for complex fault detection equipment. Instead, a frequency converter generates corresponding DC excitation voltage signals and AC excitation voltage signals, which are applied to the three-phase circuit of the motor to be tested. By extracting the test response data of the motor to be tested, an algorithm can accurately determine the insulation fault status and location of the motor to be tested, effectively reducing the cost of detecting motor insulation faults. Furthermore, because the motor insulation fault detection method proposed in the present invention is applied to the motor in an offline state, it is not easily affected by operating conditions, and the insulation fault detection results are accurate and highly precise.

[0120] It should be understood that, although the steps in the flowcharts of the above embodiments are shown in sequence as indicated by the arrows, these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be performed in other orders. Moreover, at least a portion of the steps in the flowcharts of the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily to be performed in sequence, but can be performed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0121] Based on the same inventive concept, embodiments of the present application further provide a motor insulation fault detection device for implementing the aforementioned motor insulation fault detection method. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations of one or more motor insulation fault detection device embodiments provided below can be found in the aforementioned limitations of the motor insulation fault detection method and are not further elaborated here.

[0122] In one embodiment, Figure 7 As shown, a motor insulation fault detection device 600 is provided, comprising: a voltage generating module 610, a voltage applying module 620, an index calculating module 630 and a fault detection module 640, wherein:

[0123] The voltage generating module 610 is used to generate a DC excitation voltage and an AC excitation voltage according to the power-on signal of the inverter;

[0124] A voltage application module 620 is used to apply a DC excitation voltage and an AC excitation voltage to any two phases of the motor to be tested, respectively, to obtain test response data of any two phases of the motor to be tested;

[0125] An index calculation module 630 is used to calculate an insulation degradation index based on the test response data;

[0126] The fault detection module 640 is configured to determine the insulation status of the motor to be tested based on the insulation degradation index and a preset index threshold.

[0127] In one embodiment, the motor insulation fault detection device 600 further includes:

[0128] The fault location determination module is used to calculate the reference equivalent resistance and reference equivalent inductance between any two phases of the motor to be tested based on the test response data; calculate the equivalent resistance change rate and the equivalent inductance change rate between any two phases of the motor to be tested based on the initial equivalent resistance, initial equivalent inductance, reference equivalent resistance and reference equivalent inductance between any two phases of the motor to be tested; and determine the insulation fault location of the motor to be tested based on the equivalent resistance change rate and the equivalent inductance change rate between any two phases of the motor to be tested.

[0129] In one embodiment, the equivalent resistance change rate between any two phases of the motor to be tested includes a first equivalent resistance change rate, a second equivalent resistance change rate and a third equivalent resistance change rate, and the equivalent inductance change rate between any two phases of the motor to be tested includes a first equivalent inductance change rate, a second equivalent inductance change rate and a third equivalent inductance change rate. The fault position determination module is specifically used to sort the first equivalent resistance change rate, the second equivalent resistance change rate and the third equivalent resistance change rate, and sort the first equivalent inductance change rate, the second equivalent inductance change rate and the third equivalent inductance change rate; if the first equivalent resistance change rate is the smallest or the first equivalent inductance change rate is the smallest, it is determined that the insulation fault position of the motor to be tested is phase A; if the second equivalent resistance change rate is the smallest or the second equivalent inductance change rate is the smallest, it is determined that the insulation fault position of the motor to be tested is phase B; if the third equivalent resistance change rate is the smallest or the third equivalent inductance change rate is the smallest, it is determined that the insulation fault position of the motor to be tested is phase C.

[0130] In one embodiment, the voltage application module 620 is specifically used to apply a DC excitation voltage and an AC excitation voltage to phase A and phase B of the motor to be tested to obtain test response data of phase A and phase B of the motor to be tested; apply a DC excitation voltage and an AC excitation voltage to phase A and phase C of the motor to be tested to obtain test response data of phase A and phase C of the motor to be tested; apply a DC excitation voltage and an AC excitation voltage to phase B and phase C of the motor to be tested to obtain test response data of phase B and phase C of the motor to be tested.

[0131] In one embodiment, the index calculation module 630 is specifically used to calculate the reference equivalent resistance and reference equivalent inductance between any two phases of the motor to be tested based on the test response data; and calculate the resistance insulation degradation index and the inductance insulation degradation index based on the reference equivalent resistance and reference equivalent inductance between any two phases of the motor to be tested.

[0132] In one embodiment, the fault detection module 640 is specifically used to determine that the motor is in an insulation degradation state if the resistance insulation degradation index is greater than a first index threshold, or the inductance insulation degradation index is greater than the first index threshold; if the resistance insulation degradation index is greater than a second index threshold, or the inductance insulation degradation index is greater than the second index threshold, determine that the motor is in an insulation fault state, wherein the second index threshold is greater than the first index threshold.

[0133] In summary, this embodiment proposes a motor insulation fault detection device that eliminates the need for complex fault detection equipment. Instead, a frequency converter generates corresponding DC excitation voltage signals and AC excitation voltage signals, which are applied to the three-phase circuit of the motor to be tested. By extracting the test response data of the motor to be tested, an algorithm can accurately determine the insulation fault status and location of the motor to be tested, effectively reducing the cost of detecting motor insulation faults. Furthermore, because the motor insulation fault detection device proposed in the present invention is applied to the motor in an offline state, it is not easily affected by operating conditions, and the insulation fault detection results are accurate and highly precise.

[0134] Each module in the motor insulation fault detection device can be implemented in whole or in part through software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in hardware form, or can be stored in a computer device memory in software form, so that the processor can call and execute the corresponding operations of each module.

[0135] In one embodiment, Figure 8 As shown, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the following steps are implemented:

[0136] Generate DC excitation voltage and AC excitation voltage according to the power-on signal of the inverter;

[0137] Applying a DC excitation voltage and an AC excitation voltage to any two phases of the motor to be tested respectively to obtain test response data of any two phases of the motor to be tested;

[0138] The insulation degradation index is calculated based on the test response data;

[0139] The insulation status of the motor to be tested is determined based on the insulation degradation index and a preset index threshold.

[0140] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0141] Generate DC excitation voltage and AC excitation voltage according to the power-on signal of the inverter;

[0142] Applying a DC excitation voltage and an AC excitation voltage to any two phases of the motor to be tested respectively to obtain test response data of any two phases of the motor to be tested;

[0143] The insulation degradation index is calculated based on the test response data;

[0144] The insulation status of the motor to be tested is determined based on the insulation degradation index and a preset index threshold.

[0145] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, database or other media used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processor involved in the various embodiments provided herein may be, but are not limited to, a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, and the like.

[0146] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0147] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for detecting motor insulation fault, characterized in that: The method comprises: Generate DC excitation voltage and AC excitation voltage according to the power-on signal of the inverter; Applying the DC excitation voltage and the AC excitation voltage to any two phases of the motor to be tested respectively to obtain test response data of any two phases of the motor to be tested; Calculating an insulation degradation index based on the test response data; Determining the insulation state of the motor to be tested according to the insulation degradation index and a preset index threshold; The calculating the insulation degradation index according to the test response data includes: Calculating a reference equivalent resistance and a reference equivalent inductance between any two phases of the motor to be tested according to the test response data; Calculating a resistance insulation degradation index and an inductance insulation degradation index according to a reference equivalent resistance and a reference equivalent inductance between any two phases of the motor to be tested; The calculation formula of the resistance insulation degradation index is: Among them, FI R is the resistance insulation degradation index, is the reference equivalent resistance between phase A and phase B, is the reference equivalent resistance between phase B and phase C, is the reference equivalent resistance between phase C and phase A; And / or, the calculation method of the inductor insulation degradation index includes: in, FI ΔL is the inductor insulation degradation index, is the initial equivalent inductance between phase A and phase B, is the initial equivalent inductance between phase B and phase C, is the initial equivalent inductance between phase C and phase A, is the reference equivalent inductance between phase A and phase B, is the reference equivalent inductance between phase B and phase C, is the reference equivalent inductance between phase C and phase A.

2. The method according to claim 1, characterized in that The method further comprises: Calculating a reference equivalent resistance and a reference equivalent inductance between any two phases of the motor to be tested according to the test response data; Calculating the equivalent resistance change rate and the equivalent inductance change rate between any two phases of the motor to be tested according to the initial equivalent resistance, the initial equivalent inductance, the reference equivalent resistance, and the reference equivalent inductance between any two phases of the motor to be tested; The insulation fault position of the motor to be tested is determined according to the equivalent resistance change rate and the equivalent inductance change rate between any two phases of the motor to be tested.

3. The method according to claim 2, characterized in that The equivalent resistance change rate between any two phases of the motor to be tested includes a first equivalent resistance change rate, a second equivalent resistance change rate, and a third equivalent resistance change rate; the equivalent inductance change rate between any two phases of the motor to be tested includes a first equivalent inductance change rate, a second equivalent inductance change rate, and a third equivalent inductance change rate; and determining the insulation fault position of the motor to be tested based on the equivalent resistance change rate and the equivalent inductance change rate between any two phases of the motor to be tested includes: sorting the first equivalent resistance change rate, the second equivalent resistance change rate, and the third equivalent resistance change rate, and sorting the first equivalent inductance change rate, the second equivalent inductance change rate, and the third equivalent inductance change rate; If the first equivalent resistance change rate is the smallest or the first equivalent inductance change rate is the smallest, determining that the insulation fault position of the motor to be tested is phase A; If the second equivalent resistance change rate is the smallest or the second equivalent inductance change rate is the smallest, determining that the insulation fault position of the motor to be tested is phase B; If the third equivalent resistance change rate is the smallest or the third equivalent inductance change rate is the smallest, it is determined that the insulation fault position of the motor to be tested is phase C.

4. The method according to claim 1, wherein The step of applying the DC excitation voltage and the AC excitation voltage to any two-phase bridge arms of the motor to be tested respectively to obtain test response data of any two-phase bridge arms of the motor to be tested includes: Applying the DC excitation voltage and the AC excitation voltage to phases A and B of the motor to be tested to obtain test response data of phases A and B of the motor to be tested; Applying the DC excitation voltage and the AC excitation voltage to phases A and C of the motor to be tested to obtain test response data of phases A and C of the motor to be tested; The DC excitation voltage and the AC excitation voltage are applied to the B-phase and the C-phase of the motor to be tested to obtain test response data of the B-phase and the C-phase of the motor to be tested.

5. The method according to claim 1, wherein Determining the insulation state of the motor to be tested according to the insulation degradation index and a preset index threshold includes: If the resistance insulation degradation index is greater than or equal to the first index threshold, or the inductance insulation degradation index is greater than or equal to the first index threshold, it is determined that the motor is in an insulation degradation state; If the resistance insulation degradation index is greater than or equal to a second index threshold, or the inductance insulation degradation index is greater than or equal to the second index threshold, it is determined that the motor is in an insulation fault state, wherein the second index threshold is greater than the first index threshold.

6. A motor insulation fault detection device, characterized in that: The device comprises: A voltage generation module is used to generate a DC excitation voltage and an AC excitation voltage according to a power-on signal of the inverter; A voltage application module, configured to apply the DC excitation voltage and the AC excitation voltage to any two phases of the motor to be tested, respectively, to obtain test response data of any two phases of the motor to be tested; An index calculation module, configured to calculate an insulation degradation index based on the test response data; a fault detection module, configured to determine the insulation status of the motor to be tested based on the insulation degradation index and a preset index threshold; The index calculation module is specifically used to calculate the reference equivalent resistance and reference equivalent inductance between any two phases of the motor to be tested according to the test response data; calculate the resistance insulation degradation index and the inductance insulation degradation index according to the reference equivalent resistance and reference equivalent inductance between any two phases of the motor to be tested; The calculation formula of the resistance insulation degradation index is: Among them, FI R is the resistance insulation degradation index, is the reference equivalent resistance between phase A and phase B, is the reference equivalent resistance between phase B and phase C, is the reference equivalent resistance between phase C and phase A; And / or, the calculation method of the inductor insulation degradation index includes: in, FI ΔL is the inductor insulation degradation index, is the initial equivalent inductance between phase A and phase B, is the initial equivalent inductance between phase B and phase C, is the initial equivalent inductance between phase C and phase A, is the reference equivalent inductance between phase A and phase B, is the reference equivalent inductance between phase B and phase C, is the reference equivalent inductance between phase C and phase A.

7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the motor insulation fault detection method according to any one of claims 1 to 5 are implemented.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the motor insulation fault detection method according to any one of claims 1 to 5 are implemented.

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