Thermal protection detection system for motor stator assembly

Abstract

The utility model belongs to the technical field of motor detection, and particularly relates to a thermal protection detection system for a motor stator assembly. In order to overcome the defect that the thermal protection of a motor stator is not detected in the existing motor production process, the utility model adopts the following technical scheme: the thermal protection detection system for the motor stator assembly comprises a detection platform; a coil winding joint; a thermistor joint; a thermal protector joint; a DC power source; a voltage and current module; the main control board is used for switching on a direct-current power supply, switching off the direct-current power supply according to the state of the thermal protector, receiving voltage and current signals before and after the coil winding is electrified, calculating the temperature rise of the coil winding and receiving a thermistor temperature signal; and finally, comparing the received temperature of the thermistor with the temperature after the temperature rise of the coil winding and the allowable temperature range of the thermal protector. The beneficial effects of the utility model are that the detection of the thermistor and the thermal protector of the motor stator assembly to be detected is realized, and the operation reliability of the motor after the motor is offline is finally ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of motor detection, and in particular relates to a motor stator assembly thermal protection detection system. Background Art

[0002] The most common problem when the motor runs for a long time is excessive temperature rise caused by heat accumulation. Excessive temperature rise can lead to various problems such as short circuit and burning of the insulation layer of the motor stator coil winding, high-temperature failure of the magnetic steel, etc. Severe problems may even cause fire, posing a hidden danger to personal and property safety.

[0003] Air cooling has a simple structure, low price, and small size, and is widely used in small and medium-sized motors with low heat dissipation requirements. However, the heat dissipation capacity of the air cooling structure is relatively poor compared to the water cooling system, so the thermal management of the motor control system is particularly important. The commonly used thermal management solution is to implant thermistors and thermal protectors (thermal protection switches) inside the stator coil windings during motor production. Thermistors are used to monitor the temperature rise of the motor stator. When the temperature approaches the preset value, the system will actively reduce the motor power to reduce the heat generation to compensate for the thermal balance, so that the motor can continue to work. The thermal protection switch is used to automatically cut off the power supply when the motor is overheated or overloaded to prevent motor damage and avoid serious accidents.

[0004] In the process of producing this type of motor, thermistors and thermal protection switches are inserted between the windings through tooling after the stator winding is completed. Improper operation by workers or device quality problems may cause the devices to fail or act prematurely, affecting the normal operation of the motor. If the thermal protection function of the motor is not working properly after the motor is put into operation, it will need to be reworked, inspected, disassembled, and replaced, which will waste a lot of manpower and material resources. Therefore, testing the thermal protection function of the motor stator before the motor is assembled can screen out the stator assemblies where the thermal protection devices cannot work properly. For the faulty stator assemblies, the source of the fault can be quickly and accurately identified. After confirming the cause of the problem, you can directly return to the previous process to repair or replace the device, which will not affect the subsequent processes, and ultimately ensure the operating reliability and service life of the motor after it is offline. Summary of the invention

[0005] The utility model aims at the deficiency that the thermal protection of the motor stator is not detected in the existing motor production process, and provides a motor stator assembly thermal protection detection system, which detects the thermal protection of the motor stator assembly, i.e. the thermistor and the thermal protector, before the motor is offline, so as to find out in advance whether the thermal protection of the motor stator assembly is faulty, so that the fault can be checked and solved in time.

[0006] To achieve the above purpose, the utility model adopts the following technical solution: a motor stator assembly thermal protection detection system, the motor stator assembly thermal protection detection system comprising:

[0007] Testing platform, used to place the stator assembly of the motor under test;

[0008] Coil winding connector, used to connect the coil winding of the stator assembly of the motor under test;

[0009] Thermistor connector, used to connect the thermistor of the stator assembly of the motor under test;

[0010] Thermal protector connector, used to connect the thermal protector of the stator assembly of the motor under test;

[0011] A DC power supply for supplying power to the coil windings of the stator assembly of the motor under test;

[0012] A voltage and current module is used to detect the voltage and current of the coil winding of the stator assembly of the motor under test;

[0013] The main control board is used to connect the DC power supply, disconnect the DC power supply according to the status of the thermal protector, receive the voltage and current signals of the coil winding before and after power is supplied and calculate the temperature rise of the coil winding, receive the thermistor temperature signal, and finally compare the received thermistor temperature with the temperature after the coil winding temperature rise and the allowable temperature range of the thermal protector.

[0014] The utility model discloses a motor stator assembly thermal protection detection system, comprising a detection platform, a coil winding joint, a thermistor joint, a thermal protector joint, a DC power supply, a voltage and current module, and a main control board. The main control board is connected to the DC power supply, disconnects the DC power supply according to the state of the thermal protector, receives the voltage and current signals of the coil winding before and after power-on and calculates the temperature rise of the coil winding, receives the thermistor temperature signal, and finally compares the received thermistor temperature with the temperature after the coil winding temperature rise and the allowable temperature range of the thermal protector, so as to realize the detection of the thermistor and the thermal protector of the motor stator assembly under test, and by screening out the stator assembly whose thermal protection device cannot work normally, the source of the fault can be quickly and accurately checked for the stator assembly with fault, and after confirming the cause of the problem, the device can be directly returned to the previous process for repair or replacement, which will not affect the subsequent processes, and finally ensure the operation reliability and service life of the motor after it is offline.

[0015] As an improvement, the motor stator assembly thermal protection detection system further includes an ambient temperature detection module for detecting ambient temperature, and the main control board receives an ambient temperature signal from the ambient temperature detection module. By calculating the ambient temperature difference before and after the test, a more accurate temperature rise of the coil winding can be obtained.

[0016] As an improvement, the resistance method is used to calculate the temperature rise of the coil winding. The calculation formula is:

[0017] K=(R2-R1) / R1×(234.5+T1)-(T2-T1);

[0018] Where K is the coil winding temperature rise in degrees Celsius, R1 is the resistance of the coil winding at the beginning of the test, R2 is the resistance of the coil winding at the end of the test, T1 is the temperature of the coil winding at the beginning of the test in degrees Celsius, and T2 is the temperature of the coil winding at the end of the test in degrees Celsius.

[0019] As an improvement, the main control board records the voltage and current of the coil winding at the beginning of the test and calculates the cold resistance. The main control board also records the voltage and current of the coil winding at the end of the test, that is, when the thermal protector enters the protection state, thereby calculating the thermal resistance when the thermal protector enters the protection state.

[0020] As an improvement, the temperature of the coil winding after temperature rise is T3, T3 = T1 + K, assuming that the final received thermistor temperature is T4, assuming that the allowable temperature range of the thermal protector is T5, then:

[0021] When T4=T3=T5, the product is considered qualified;

[0022] When T4=T3≠T5, the thermal protector is judged to be unqualified;

[0023] When T4≠T3=T5, the thermistor is judged to be unqualified.

[0024] As an improvement, the motor stator assembly thermal protection detection system further includes a gear switch for presetting the thermal protector disconnection temperature.

[0025] As an improvement, the motor stator assembly thermal protection detection system further includes a time relay for presetting an upper limit of the continuous power-on time of the DC power supply.

[0026] As an improvement, the motor stator assembly thermal protection detection system further includes a digital display temperature module for displaying the coil winding of the motor stator assembly under test in real time.

[0027] As an improvement, the motor stator assembly thermal protection detection system further includes a prompt component, which includes an indicator light and / or a buzzer.

[0028] As an improvement, the indicator light includes a green qualified indicator light and a red unqualified indicator light.

[0029] The beneficial effects of the motor stator assembly thermal protection detection system of the utility model are: it includes a detection platform, a coil winding joint, a thermistor joint, a thermal protector joint, a DC power supply, a voltage and current module, and a main control board. The main control board connects the DC power supply, disconnects the DC power supply according to the state of the thermal protector, receives the voltage and current signals of the coil winding before and after power-on and calculates the temperature rise of the coil winding, receives the thermistor temperature signal, and finally compares the received thermistor temperature with the temperature after the coil winding temperature rise and the allowable temperature range of the thermal protector to realize the detection of the thermistor and the thermal protector of the motor stator assembly under test, and by screening out the stator assembly whose thermal protection device cannot work normally, for the stator assembly with fault, the source of the fault can be quickly and accurately checked, and after confirming the cause of the problem, the device can be directly returned to the previous process for repair or replacement, which will not affect the subsequent processes, and finally the operating reliability and service life of the motor after it is offline are guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural block diagram of a motor stator assembly thermal protection detection system according to Embodiment 1 of the present utility model.

[0031] Figure 2 It is a structural schematic diagram of a motor stator assembly thermal protection detection system according to Embodiment 1 of the present utility model.

[0032] In the figure, 1. DC power supply;

[0033] 2. Time relay;

[0034] 3. Digital display temperature module;

[0035] 4. Testing platform;

[0036] 5. Stator assembly;

[0037] 6. Stator coil connector;

[0038] 7. Thermal protector connector;

[0039] 8. Thermistor connector;

[0040] 9. Prompt component;

[0041] 10. Gear switch;

[0042] 11. Start button. DETAILED DESCRIPTION

[0043] The technical solutions of the embodiments of the present invention are explained and described below, but the following embodiments are only preferred embodiments of the present invention, not all. Based on the embodiments in the implementation mode, other embodiments obtained by those skilled in the art without creative work are all within the protection scope of the present invention.

[0044] See also Figure 1 and Figure 2 , a motor stator assembly 5 thermal protection detection system according to the first embodiment of the utility model, the motor stator assembly 5 thermal protection detection system comprises:

[0045] A testing platform 4, used for placing a stator assembly 5 of a motor to be tested;

[0046] A coil winding connector, used for connecting the coil winding of the stator assembly 5 of the motor under test;

[0047] Thermistor connector 8, used for connecting the thermistor of the motor stator assembly 5 under test;

[0048] A thermal protector connector 7, used for connecting a thermal protector of the stator assembly 5 of the motor under test;

[0049] A DC power supply 1, used to supply power to the coil winding of the stator assembly 5 of the motor under test;

[0050] A voltage and current module, used to detect the voltage and current of the coil winding of the stator assembly 5 of the motor under test;

[0051] The main control board is used to connect the DC power supply 1, disconnect the DC power supply 1 according to the state of the thermal protector, receive the voltage and current signals of the coil winding before and after power is supplied and calculate the temperature rise of the coil winding, receive the thermistor temperature signal, and finally compare the received thermistor temperature with the temperature of the coil winding after the temperature rise and the allowable temperature range of the thermal protector.

[0052] In this embodiment, the thermal protection detection system of the motor stator assembly 5 further includes an ambient temperature detection module for detecting ambient temperature, and the main control board receives the ambient temperature signal of the ambient temperature detection module. The ambient temperature difference before and after the test is calculated to obtain a more accurate temperature rise of the coil winding.

[0053] In other embodiments, when the ambient temperature changes slightly and / or the requirements are low, the ambient temperature detection module may not be provided.

[0054] In this embodiment, the resistance method is used to calculate the temperature rise of the coil winding, and the calculation formula is:

[0055] K=(R2-R1) / R1×(234.5+T1)-(T2-T1);

[0056] Where K is the coil winding temperature rise in degrees Celsius, R1 is the resistance of the coil winding at the beginning of the test, R2 is the resistance of the coil winding at the end of the test, T1 is the temperature of the coil winding at the beginning of the test in degrees Celsius, and T2 is the temperature of the coil winding at the end of the test in degrees Celsius.

[0057] In this embodiment, the main control board records the voltage and current of the coil winding at the beginning of the test and calculates the cold resistance R1. The main control board also records the voltage and current of the coil winding at the end of the test, that is, when the thermal protector enters the protection state, thereby calculating the thermal resistance R2 when the thermal protector enters the protection state.

[0058] In this embodiment, the temperature of the coil winding after temperature rise is T3, T3 = T1 + K, assuming that the final received thermistor temperature is T4, assuming that the allowable temperature range of the thermal protector is T5, then:

[0059] When T4=T3=T5, the product is considered qualified;

[0060] When T4=T3≠T5, the thermal protector is judged to be unqualified;

[0061] When T4≠T3=T5, the thermistor is judged to be unqualified.

[0062] In this embodiment, the thermal protection detection system of the motor stator assembly 5 further includes a position switch 10 for presetting the thermal protector disconnection temperature. Different mass-produced models can be quickly matched by setting the position switch 10. Temperature data such as 131°C and 137°C are marked around the position switch 10.

[0063] In this embodiment, the thermal protection detection system of the motor stator assembly 5 further includes a time relay 2 for presetting the upper limit of the continuous power-on time of the DC power supply 1. The time relay 2 can preset the upper limit of the continuous power-on time of the DC power supply 1 to prevent the power-on time from being too long due to the failure of the thermal protector to cut off the power in time, thereby damaging the system or burning the stator to be measured.

[0064] In this embodiment, the thermal protection detection system of the motor stator assembly 5 further includes a digital display temperature module 3 for real-time display of the coil winding of the motor stator assembly 5 under test. The digital display temperature module 3 displays the temperature of the coil winding of the stator under test on the panel in real time, so that the tester can understand the status of the stator under test in real time.

[0065] In this embodiment, the thermal protection detection system of the motor stator assembly 5 further includes a prompt component 9, and the prompt component 9 includes an indicator light and / or a buzzer.

[0066] In this embodiment, the indicator lights include a green qualified indicator light and a red unqualified indicator light.

[0067] In this embodiment, the thermistor is an NTC thermistor.

[0068] In this embodiment, the thermal protection detection system of the motor stator assembly 5 also includes an emergency stop / reset button.

[0069] In the figure, the voltage and current module for detecting the voltage and current of the stator assembly 5 is not shown.

[0070] The working principle of the thermal protection detection system of the motor stator assembly 5 of the first embodiment of the utility model is: during the test, the motor stator assembly 5 to be tested (including coil windings, thermistors and thermal protectors) is placed on the detection platform 4, the stator coil connector 6, the thermal protector connector 7, and the thermistor connector 8 are respectively connected to the corresponding connectors of the motor stator assembly 5 to be tested, the gear switch 10 is operated, the thermal protector working temperature is set according to the corresponding model, the time of the time relay 2 is set, and then the detection system is powered on, and the start button 11 is pressed. The detection system will first perform a resistance test on the stator assembly 5 and record the cold resistance R1. At the same time, the ambient temperature detection module detects the ambient temperature T1 at the beginning of the test. Then, the main control board controls the DC power supply 1 to apply a slowly increasing current to the coil winding of the stator assembly 5, and at the same time, the voltage and current module of the detection system collects the voltage and current of the coil winding. The main control board calculates the resistance R2 after the temperature rise, obtains the temperature data T2 of the ambient temperature detection module after the temperature rise, and calculates the coil winding temperature rise according to the resistance method K = (R2-R1) / R1×(234.5+T1)-(T2-T1). The main control board simultaneously detects the state of the thermal protector in the motor assembly and the thermistor signal. Once the thermal protector enters the protection state, the main control board immediately disconnects the DC power supply 1. The detection system simultaneously records the temperature rise K and the thermistor temperature T4 when disconnected. The main control board compares the thermistor temperature T4, the coil winding temperature T1+K when disconnected, and the operating temperature range of the thermal protector. If the data is within a reasonable range, the green indicator light indicates that the product is qualified. If the output red indicator light is on and the buzzer alarm prompts unqualified, the operator can determine the problematic device based on the temperature information displayed by the digital display temperature module 3. For example, when the operating temperature of the thermal protector is set to 131°C and the allowable deviation is set to ±2°C, the allowable temperature range of the thermal protector is T5 = 131±2°C. The temperature of the coil winding at the moment the thermal protector enters the protection state is T3 = T1+K. The temperature fed back by the thermistor after the temperature rise is T4 (the temperature is obtained according to the resistance value of the thermistor). If T4 = T3 = 131±2°C, that is, the temperature T4 fed back by the thermistor and the temperature T3 of the coil winding after the temperature rise are equal and both are within the range of 131±2°C, then the product can be judged to be qualified. If T4 = T3≠131±2°C, that is, the temperature fed back by the thermistor is If the temperature T4 is equal to the temperature T3 of the coil winding after the temperature rise but is not within the range of 131±2℃, the thermal protector can be judged to be unqualified; if T4≠T3=131±2℃, that is, the temperature T4 fed back by the thermistor and the temperature T3 of the coil winding after the temperature rise are not equal and the temperature T3 of the coil winding after the temperature rise is within the range of 131±2℃, the thermistor can be judged to be unqualified; if T4≠T3≠131±2℃, that is, the temperature T4 fed back by the thermistor and the temperature T3 of the coil winding after the temperature rise are not equal and both are not within the range of 131±2℃, it can be judged that both the thermal protector and the thermistor are unqualified.

[0071] The beneficial effects of the thermal protection detection system for the motor stator assembly 5 of the first embodiment of the utility model are: it includes a detection platform 4, a coil winding connector, a thermistor connector 8, a thermal protector connector 7, a DC power supply 1, a voltage and current module, and a main control board. The main control board connects the DC power supply 1, disconnects the DC power supply 1 according to the state of the thermal protector, receives the voltage and current signals before and after the coil winding is energized and calculates the temperature rise of the coil winding, receives the thermistor temperature signal, and finally compares the received thermistor temperature with the temperature after the coil winding temperature rise and the allowable temperature range of the thermal protector to realize the detection of the thermistor and the thermal protector of the motor stator assembly 5 under test, and by screening out the stator assembly 5 whose thermal protection device cannot work normally, for the stator assembly 5 with a fault, it is possible to quickly and accurately check whether the fault source is the thermal protector or the thermistor. After confirming the cause of the problem, it is possible to directly return to the previous process to repair or replace the device without affecting the subsequent processes, and finally ensure the operating reliability and service life of the motor after it is offline.

[0072] The above is only a specific implementation of the invention, but the protection scope of the invention is not limited thereto. Those skilled in the art should understand that the invention includes but is not limited to the contents described in the above specific implementation. Any modification that does not deviate from the functional and structural principles of the invention will be included in the scope of the claims.

Claims

1. A motor stator assembly thermal protection detection system, characterized in that: The motor stator assembly thermal protection detection system comprises: A testing platform (4) for placing a stator assembly (5) of a motor to be tested; A coil winding connector, used for connecting the coil winding of the stator assembly (5) of the motor under test; A thermistor connector (8) for connecting a thermistor of a stator assembly (5) of a motor under test; A thermal protector connector (7) for connecting to a thermal protector of a stator assembly (5) of a motor under test; A direct current power supply (1) for supplying power to the coil windings of the stator assembly (5) of the motor under test; A voltage and current module, used to detect the voltage and current of the coil winding of the stator assembly (5) of the motor under test; The main control board is used to connect a DC power supply (1), disconnect the DC power supply (1) according to the state of the thermal protector, receive voltage and current signals of the coil winding before and after power is supplied and calculate the temperature rise of the coil winding, receive a thermistor temperature signal, and finally compare the received thermistor temperature with the temperature of the coil winding after the temperature rise and the allowable temperature range of the thermal protector.

2. The motor stator assembly thermal protection detection system according to claim 1, characterized in that: The motor stator assembly thermal protection detection system further includes an ambient temperature detection module for detecting ambient temperature, and the main control board receives an ambient temperature signal from the ambient temperature detection module.

3. The motor stator assembly thermal protection detection system according to claim 2, characterized in that: The resistance method is used to calculate the temperature rise of the coil winding. The calculation formula is: K=(R2-R1) / R1×(234.5+T1)-(T2-T1); Where K is the coil winding temperature rise in degrees Celsius, R1 is the resistance of the coil winding at the beginning of the test, R2 is the resistance of the coil winding at the end of the test, T1 is the temperature of the coil winding at the beginning of the test in degrees Celsius, and T2 is the temperature of the coil winding at the end of the test in degrees Celsius.

4. The motor stator assembly thermal protection detection system according to claim 3, characterized in that: The main control board records the voltage and current of the coil winding at the beginning of the test and calculates the cold resistance. The main control board also records the voltage and current of the coil winding at the end of the test, that is, when the thermal protector enters the protection state, thereby calculating the thermal resistance when the thermal protector enters the protection state.

5. The motor stator assembly thermal protection detection system according to claim 3, characterized in that: The temperature of the coil winding after temperature rise is T3, T3 = T1 + K, assuming that the final received thermistor temperature is T4, assuming that the allowable temperature range of the thermal protector is T5, then: When T4=T3=T5, the product is considered qualified; When T4=T3≠T5, the thermal protector is judged to be unqualified; When T4≠T3=T5, the thermistor is judged to be unqualified.

6. The motor stator assembly thermal protection detection system according to claim 1, characterized in that: The motor stator assembly thermal protection detection system also includes a gear switch (10) for presetting a thermal protector disconnection temperature.

7. The motor stator assembly thermal protection detection system according to claim 1, characterized in that: The motor stator assembly thermal protection detection system further comprises a time relay (2) for presetting an upper limit of the continuous power-on time of the DC power supply (1).

8. The motor stator assembly thermal protection detection system according to claim 1, characterized in that: The motor stator assembly thermal protection detection system further comprises a digital display temperature module (3) for displaying in real time the coil winding temperature of the motor stator assembly (5) being tested.

9. The motor stator assembly thermal protection detection system according to claim 1, characterized in that: The motor stator assembly thermal protection detection system further comprises a prompt component (9), and the prompt component (9) comprises an indicator light and / or a buzzer.

10. The motor stator assembly thermal protection detection system according to claim 9, characterized in that: The indicator lights include a green qualified indicator light and a red unqualified indicator light.

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