Motor stator vertical lapping wire detection device

Abstract

The utility model belongs to the field of motor detection, and relates to a motor stator vertical lapping wire detection device, which is characterized in that a measurement control main module is connected with an upper computer module, a measurement module and an AC voltage output module, a motor stator to be detected is connected with the measurement module and the AC voltage output module, one end of an inductor L1 in the measurement module is connected with a load loop end, and the other end of the inductor L1 is connected with one end of a resistor R1; the other end of R3 is grounded and one end of a resistor R4; the other end of R4 is connected with the non-inverting input end of an operational amplifier U1 and one end of a capacitor C3; the other end of C3 is connected with the other end of C2 and one end of a resistor R5; the other end of R5 is connected with the inverting input end of U1; and the operational amplifier circuit is connected with the AD converter. According to the utility model, low-voltage nondestructive testing is realized, and the working condition of the vertical lapping wire of the motor stator reaches a 100% detection rate.

Description

Technical Field

[0001] The utility model belongs to the technical field of motor detection, and particularly relates to a detection device for the vertical overlapping wire of a motor stator. Background Art

[0002] Before leaving the factory, the motor stator generally undergoes routine safety performance tests to detect whether the motor stator has sufficient withstand voltage capacity and whether the quality of the insulating materials used can meet the production requirements. During the production process of the motor stator, due to reasons such as production technology and machine failures, defects will occur where the internal enameled wire overlaps with the silicon steel sheet iron core or the motor stator shell during wire embedding. Hereinafter, this overlapping structure defect will be simply referred to as the vertical overlapping wire of the motor stator. If this defect cannot be effectively detected, after the motor is put into use, due to long-term vibration, heating, friction, etc., wear will occur at the position where the enameled wire contacts the stator core, causing poor insulation, and ultimately resulting in motor leakage or burnout.

[0003] Currently, motor manufacturers arrange 1 - 2 people on each stator production line to visually inspect such abnormal conditions, but the detection effect is limited, and it greatly increases the labor cost of motor manufacturers. Therefore, developing a device that can accurately and stably detect the vertical overlapping wire of the motor stator will greatly improve the safety performance test of the motor stator. Content of the Utility Model

[0004] In order to solve the above technical problems, the utility model provides a detection device for the vertical overlapping wire of a motor stator. The technical solution adopted by the utility model is as follows:

[0005] The detection device for the vertical overlapping wire of a motor stator includes a host computer module, a measurement control main module, a measurement module, and an AC voltage output module. The measurement control main module is electrically connected to the host computer module, the measurement module, and the AC voltage output module respectively. The motor stator to be tested is electrically connected to the measurement module and the AC voltage output module respectively. The measurement module includes an inductor L1. One end of L1 is connected to the load circuit end, the other end of L1 is connected to one end of a first resistor R1. The other end of R1 is connected to one end of a first capacitor C1. The other end of C1 is connected to one end of a second resistor R2 and a third resistor R3. The other end of R2 is connected to one end of a second capacitor C2. The other end of R3 is grounded and connected to one end of a fourth resistor R4. The other end of R4 is connected to the non-inverting input terminal of an operational amplifier U1 and one end of a third capacitor C3. The other end of C3 is connected to the other end of C2 and one end of a fifth resistor R5. The other end of R5 is connected to the inverting input terminal of U1. The inverting input terminal of U1 is simultaneously connected to the output terminal of U1. The output terminal of U1 is connected to an operational amplifier amplification circuit. The operational amplifier amplification circuit is connected to an AD converter. The AD converter is electrically connected to the measurement control main module.

[0006] Preferably, it further includes a first power supply module and a second power supply module. The first power supply module is electrically connected to the main measurement and control module, the measurement module, and the AC voltage output module respectively, and the second power supply module is electrically connected to the host computer module.

[0007] Preferably, the main measurement and control module includes a single-chip microcomputer and an isolation circuit.

[0008] Preferably, the single-chip microcomputer adopts a single-chip microcomputer of the STM32 series, and the isolation circuit adopts an ISO7740DWR digital signal isolation module packaged by TI.

[0009] Preferably, the host computer module adopts a 13.3-inch Android all-in-one screen.

[0010] Advantages of the present utility model:

[0011] (1) Compared with the existing test scheme, the present utility model can realize low-voltage non-destructive testing and basically will not damage the motor stator; (2) In the measurement module designed specifically in the present utility model, the extraction method of the main test signal and the appropriate band-pass filter can achieve a 100% detection rate for the condition of the motor stator's vertical overlapping wire; (3) The test speed of the present utility model is fast, and the test can be completed within 1 s, which is suitable for the test beat of motor manufacturers' production. Description of the drawings

[0012] The drawings are used to provide a further understanding of the present utility model, and constitute a part of the specification. Together with the embodiments of the present utility model, they are used to explain the present utility model and do not constitute a limitation to the present utility model. In the drawings:

[0013] Figure 1 It is a schematic diagram of the equivalent model of the normal insulation performance of the motor stator;

[0014] Figure 2 It is a schematic diagram of the equivalent model of the insulation performance of the motor stator's vertical overlapping wire. 2a is the first equivalent model, 2b is the second equivalent model, and 2c is the third equivalent model;

[0015] Figure 3 It is a wiring schematic diagram of the existing motor stator withstand voltage test;

[0016] Figure 4 It is a structural schematic diagram of the motor stator vertical overlapping wire detection device according to the embodiment of the present utility model;

[0017] Figure 5 It is a structural schematic diagram of the measurement module according to the embodiment of the present utility model. Detailed implementation manners

[0018] The technical solution of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of the embodiments.

[0019] This structural defect of the motor stator drooping wire is theoretically not easily detectable. For example, Figure 1 As shown, it is an equivalent model of the insulation performance of a normal motor stator. There is an insulating material between the motor winding and the stator housing, such as: enameled wire insulating paint, insulating paper, and air (there are gaps between the insulating paper and the inner wall of the stator core).

[0020] For example, Figure 2 As shown, it is an equivalent model of the insulation performance of the motor stator drooping wire. Figure 2 In equivalent model 1 shown in a, the enameled wire of the motor stator is laid on the iron core. There is only one layer of insulating paint as the insulating material between the motor winding and the stator housing, and the insulating paint is not damaged. The voltage withstand capacity of the insulating paint is several hundred volts to over a thousand volts, which greatly increases the detection difficulty. This defect is hereinafter simply referred to as type A defect. Figure 2 In equivalent model 2 shown in b, the enameled wire of the motor stator is laid on the iron core, and the insulating paint is damaged. The conductive material used in the motor stator is basically exposed on the stator iron core. This defect is relatively easy to detect. This defect is hereinafter simply referred to as type B defect. Figure 2 In equivalent model 3 shown in c, the enameled wire of the motor stator is not completely laid on the iron core, with a very small distance (within 1 mm), and the insulating paint is damaged. This defect is relatively not easily detectable. This defect is hereinafter simply referred to as type C defect.

[0021] In order to detect this defect of the motor stator drooping wire, two common testing methods are currently used for detection. One is the voltage withstand test, that is, a 50 / 60 Hz power frequency high voltage is applied between the stator winding and the iron core, and the magnitude of the current in the detection circuit is detected. This method is the most commonly used testing method for the drooping wire defect of current motor products. The voltage withstand test is relatively simple. For example, Figure 3As shown, it demonstrates the wiring method for the withstand voltage test of the motor stator. A high voltage is applied between the three-phase windings (UVW) of the motor stator and the stator housing. That is, the high-end HV of the withstand voltage tester is connected to the UVW terminals of the motor stator, and the loop RTN terminal is connected to the stator core housing of the motor. Generally, the magnitude of the high voltage is set according to the standards formulated by the motor manufacturer. The basic principle of the withstand voltage test is based on Ohm's law, and the leakage current between the stator winding and the housing is used to represent the insulation performance of the tested motor stator. For a normal motor stator and a stator with Class A defects, when using the withstand voltage test, the magnitude of the leakage current is basically the same, which also indicates that the stator of a Class A defect motor cannot be detected by a normal withstand voltage tester. For a Class B defect, the withstand voltage tester reports breakdown, indicating that the withstand voltage tester can detect Class B defects. For a Class C defect, the withstand voltage tester reports qualified because even if the insulating paint is damaged, there is still air insulation between the damaged enameled wire and the stator core of the motor stator, and the withstand voltage cannot break down. Moreover, the high-voltage characteristic of the withstand voltage tester is a destructive test for the motor stator and will cause damage to the stator. According to the feedback from the motor manufacturer, the stator of a Class B defect motor only accounts for 5% of the total number of drooping wires. Therefore, using the withstand voltage test to detect this type of defect has limited improvement effect.

[0022] Another one is the arc test, which is also to apply a 50 / 60 Hz power frequency high voltage between the stator winding and the iron core. If arcing occurs inside the stator, it can be detected through this method. It is more sensitive than the first method, but it is not as widely used as the withstand voltage test. The arc test is detected using the arc detection equipment of Fluke. Arc detection is a way to detect gas discharge. The output method is basically the same as that of the withstand voltage test. The difference is that the withstand voltage test measures the effective value of the 50 / 60 Hz power frequency current in the loop, while the arc detection equipment of Fluke measures the peak value of the current in the loop. For the Figure 2 b and Figure 2 c working conditions, because the enameled wire is damaged and meets the discharge conditions, it can be detected by the arc detection equipment of Fluke. However, for Class A defects, since the enameled wire is not damaged and there is no obvious discharge phenomenon, the arc detection equipment of Fluke cannot detect it. According to the feedback from the motor manufacturer, the stator of Class B and Class C defect motors accounts for 15% of the total number of drooping wires of the motor stator. Compared with the withstand voltage test, there is improvement, but the problem still cannot be completely solved.

[0023] From the above description, it is found that neither the withstand voltage test nor the arc detection test can well cover and solve the problem of testing the stator drooping wires of the motor. The main reason is that type A defects are not easily detected. Both the withstand voltage test and the arc detection test measure the current signal in the high-voltage circuit. The 50 / 60Hz signal of the withstand voltage test is more suitable for type B defects, while the signal between 30kHz and 250kHz of the arc detection test is more suitable for type C defects. There are damages with a small distance, which can meet the conditions of weak discharge and arcing, and the frequency of the generated arc signal is relatively high. Therefore, it is more vulnerable to interference, resulting in false test judgments, that is, it is easy to judge qualified products as unqualified. For type A defects, the enameled wire is not damaged, and the signal generated in the circuit has a lower frequency than the arc detection signal but a higher frequency than the withstand voltage test signal, with a frequency between 1kHz and 60kHz, and the signal amplitude is relatively small, making it even more difficult to detect.

[0024] The utility model designs a set of low-voltage non-destructive detection device for the stator drooping wires of the motor in view of the problems of low detection rate and false judgment of the stator drooping wire defects of the motor by the withstand voltage and arc detection tests, as well as the problem that the high withstand voltage damages the motor stator. The stator drooping wire detection device of the motor mainly includes a voltage output module and a measurement module. The withstand voltage level of the conventional motor stator is basically about AC1800V, and the voltage is relatively high. The voltage output module of this device can output an alternating voltage with a frequency of 50 / 60Hz and an effective voltage value of several hundred volts, and the measurement module can accurately test the signal with a frequency between 1kHz and 60kHz and a relatively small signal amplitude in the circuit. By outputting an alternating voltage of several hundred volts, the detection rate of the stator drooping wire defects of the motor can reach 100%, without false judgment, truly achieving low-voltage non-destructive detection.

[0025] As Figure 4 shown, the stator drooping wire detection device for detecting the enameled wire of the motor stator lying on the stator core mainly includes: a host computer module, a measurement control main module, a measurement module, an alternating voltage output module, a power supply module one, and a power supply module two. The measurement control main module is electrically connected to the host computer module, the measurement module, the alternating voltage output module, and the power supply module one respectively. The power supply module one is electrically connected to the measurement module and the alternating voltage output module respectively, and the power supply module two is electrically connected to the host computer module.

[0026] (1) Alternating voltage output module. The alternating voltage output module is the alternating voltage modulation output part of this device, which outputs the commercial power after rectification, inversion, filtering, and boosting by a booster, and the range of the output effective voltage value is between 300V and 800V.

[0027] (2) Measurement module. As Figure 5As shown in the figure, the measurement module includes an inductor L1. One end of the inductor L1 is connected to the load circuit terminal, and the other end of L1 is connected to one end of the first resistor R1. The other end of R1 is connected to one end of the first capacitor C1. The other end of C1 is connected to one end of the second resistor R2 and the third resistor R3. The other end of R2 is connected to one end of the second capacitor C2. The other end of R3 is grounded and connected to one end of the fourth resistor R4. The other end of R4 is connected to the non-inverting input terminal of the operational amplifier U1 and one end of the third capacitor C3. The other end of C3 is connected to the other end of C2 and one end of the fifth resistor R5. The other end of R5 is connected to the inverting input terminal of U1. The inverting input terminal of U1 is simultaneously connected to the output terminal of U1. The output terminal of U1 is connected to an operational amplifier amplification circuit, and the operational amplifier amplification circuit is connected to an AD converter for current signal sampling.

[0028] The measurement module is a very important part of the device for detecting the vertical connection wires of the motor stator. When connecting to the load circuit terminal, the current signal in the circuit is extracted and converted into a voltage signal through the inductor L1. The advantage of extracting the signal of the vertical connection wires of the motor stator through the inductor is that high-frequency signals can be completely extracted. The advantage of such a design is to retain the integrity of the signal of the vertical connection wires of the motor stator as much as possible. Then, it passes through a band-pass filter composed of resistors R1, R2, R3, R4, R5, capacitors C1, C2, C3, and the operational amplifier U1. This filter is designed according to the specific frequency of the signal of the vertical connection wires of the motor stator and can retain signals with frequencies between 1 kHz and 60 kHz. Then, it is conditioned by the operational amplifier circuit and sampled by an AD converter with a sampling rate of 250k to convert the analog signal into a digital signal.

[0029] (3) Measurement control main module. The measurement control main module consists of a single-chip microcomputer and an isolation circuit. Among them, the single-chip microcomputer selects a single-chip microcomputer of the STM32 series, and the isolation circuit selects the ISO7740DWR digital signal isolation module packaged by TI to achieve. The isolation circuit is mainly added to the signal transmission part of the measurement module and the AC voltage output module to play a certain isolation and protection role. The function of this module is to control the voltage output of the AC voltage output module and achieve control during its inversion process. In addition, the signals measured by the measurement module will be processed by algorithms, and the quality of the current test sample will be distinguished according to the difference in the signal amplitudes between the qualified product and the product with the defect of vertical connection wires. Finally, the test results will be transmitted to the upper computer module for display through network port communication.

[0030] (4) Upper computer module. The upper computer module consists of a 13.3-inch Android screen all-in-one machine. This module can achieve data interaction with the measurement control main module through network port communication, manually set the output voltage value, and send it to the measurement control main module. The measurement control main module controls the AC voltage output module to output according to the set voltage, and displays the test results after the test.

[0031] (5) Power supply module one. The power supply module one is used to supply power to the measurement module, the AC voltage output module, and the main measurement control module chip. Additionally, it is also used to provide power for the voltage transformation of the AC voltage output module.

[0032] (6) Power supply module two. The power supply module two is used to supply power to the host computer module.

[0033] The test process of the device is described as follows: The host computer module sets the output voltage parameters and issues a start command; the main measurement control module receives the test command sent from the host computer module through network communication and controls the AC voltage output module to output according to the set voltage; the measurement module extracts, processes, and samples the current signal in the loop and transmits it to the main measurement control module; the main measurement control module processes and judges the test data through a certain algorithm. If it is larger than the amplitude value of the qualified product, it is judged as unqualified. Similarly, if it is less than or equal to the amplitude value of the qualified product, it is judged as qualified. The test result is transmitted to the host computer module for display through network communication, and the entire test process ends.

[0034] In the embodiment of the present utility model, the current signal generated by the hanging wire of the motor stator can be completely extracted, and a band-pass filter with a frequency of 1 kHz to 60 kHz is designed; it is different from the traditional low-voltage non-destructive testing scheme for high-voltage testing.

[0035] In the embodiment of the present utility model, the technical features not described in detail are all prior arts or conventional technical means, and will not be elaborated here.

[0036] Finally, it should be noted that: The above embodiments are only specific implementation manners of the present utility model, used to illustrate the technical solutions of the present utility model, rather than limiting it. The protection scope of the present utility model is not limited thereto. Those skilled in the art should understand that: Any person skilled in the art within the technical scope disclosed by the present utility model can modify the technical solutions recorded in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes, or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present utility model, and should all be covered within the protection scope of the present utility model.

Claims

1. A motor stator vertical wire detection device, characterized in that: It includes a host computer module, a measurement control main module, a measurement module and an AC voltage output module. The measurement control main module is electrically connected to the host computer module, the measurement module and the AC voltage output module respectively. The stator of the motor to be measured is electrically connected to the measurement module and the AC voltage output module respectively. The measurement module includes an inductor L1, one end of L1 is connected to the load loop end, the other end of L1 is connected to one end of a first resistor R1, the other end of R1 is connected to one end of a first capacitor C1, the other end of C1 is connected to a second resistor R2 and one end of a third resistor R3, the other end of R2 is connected to one end of a second capacitor C2, the other end of R3 is grounded and one end of a fourth resistor R4, the other end of R4 is connected to the same-direction input end of an operational amplifier U1 and one end of a third capacitor C3, the other end of C3 is connected to the other end of C2 and one end of a fifth resistor R5, the other end of R5 is connected to the inverting input end of U1, the inverting input end of U1 is simultaneously connected to the output end of U1, the output end of U1 is connected to an operational amplifier circuit, the operational amplifier circuit is connected to an AD converter, and the AD converter is electrically connected to the measurement control main module.

2. The motor stator vertical wire detection device according to claim 1, characterized in that: It also includes power module 1 and power module 2. Power module 1 is electrically connected to the measurement control main module, the measurement module and the AC voltage output module, and power module 2 is electrically connected to the host computer module.

3. The motor stator vertical wire detection device according to claim 2, characterized in that: The measurement control main module includes a single chip microcomputer and an isolation circuit.

4. The motor stator vertical wire detection device according to claim 3, characterized in that: The single chip microcomputer adopts a single chip microcomputer of the STM32 series, and the isolation circuit adopts an ISO7740DWR digital signal isolation module packaged by TI.

5. The motor stator vertical wire detection device according to claim 2, characterized in that: The host computer module adopts a 13.3-inch Android screen all-in-one machine.

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