Compressor stall temperature rise detection system and detection method

Abstract

The present invention belongs to the technical field of detection equipment, and specifically relates to a compressor stall temperature rise detection system, including a variable frequency power supply module, a constant current source module and a DC voltage detection module, the output end of the variable frequency power supply module is used to connect the compressor, the constant current source module is used to input the DC current used for detection into the winding coil of the compressor, the DC voltage detection module is used to detect the DC voltage at both ends of the winding coil of the compressor, the output end of the variable frequency power supply module is connected to a current conversion module and an AC voltage acquisition module, the current conversion module is used to detect the stall current of the compressor, and the AC voltage acquisition module is used to detect the stall voltage of the compressor. The present invention can perform optimal matching of the protector of the compressor in a relatively short time, ensuring that the selected protector can work stably and reliably in the harsh environment inside the compressor, and also has a certain safety margin, and can adapt to various climatic conditions. In addition, the present invention also provides a compressor stall temperature rise detection method.

Description

Technical Field

[0001] The invention belongs to the technical field of detection equipment, and in particular relates to a compressor stall temperature rise detection system and a detection method. Background Art

[0002] The existing GB / T4706.1-2005 "Safety of Household and Similar Electrical Appliances Part 1: General Requirements" and GB / T4706.17-2010 "Safety of Household and Similar Electrical Appliances - Particular Requirements for Motors and Compressors" stipulate that the compressor protector is the core of the motor protection system. In order to prevent the compressor from overheating due to overload and failure to start normally, the corresponding protection device can be embedded or installed in the compressor. When the temperature of the compressor protector drops to the reset temperature, it can protect the compressor.

[0003] However, the inventors have discovered that the existing testing equipment can only measure whether the protector configured by the manufacturer can pass the most basic safety requirements, and cannot select a protector suitable for different compressors. Moreover, the protectors measured by the existing testing equipment do not have a certain margin. When the ambient temperature around the compressor changes (such as: morning and evening in a day, winter and summer in a year, etc.), it often causes current fluctuations and causes the protector to operate, resulting in the compressor constantly starting and stopping under load, and the compressor has no certain overload capacity, which greatly shortens the life of the compressor and makes the coil temperature always work below the limit safety temperature, which is far from being able to exert the characteristics of the coil material, resulting in excessive waste of coil material.

[0004] In addition, the inventors have found that the existing compressor stall temperature rise detection method is manually detected by a cold resistance meter, which is labor-intensive and time-consuming, and the detected resistance value has a large error. The temperature of the coil is prone to drop rapidly during the detection process, and it is impossible to achieve stall temperature rise detection when the protector is activated for no less than 2000 cycles when the compressor is stalled. Therefore, the existing detection method not only has a slow response time and poor performance in resisting strong electrical interference, but also cannot obtain a stable and continuous resistance change curve, and cannot simultaneously take into account the stall operation and temperature rise of the compressor. For this reason, it is urgent to propose a new detection system and a new detection method to solve the above problems. Summary of the invention

[0005] One of the purposes of the present invention is to provide a compressor stall temperature rise detection system in view of the deficiencies in the prior art, which has high reliability, good stability, strong versatility, high degree of integration and compact structure. It can not only accurately measure the specific value of the winding coil temperature rise each time the compressor stalls, but also accurately select a protector with a certain overload capacity and the most suitable for the compressor winding coil temperature protection, thereby providing a detection platform that complies with standard requirements for the selection of compressor protectors.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A compressor stall temperature rise detection system comprises a variable frequency power supply module, a constant current source module and a DC voltage detection module, wherein the output end of the variable frequency power supply module is used to connect the compressor, the constant current source module is used to input a DC current used for detection into the winding coil of the compressor, the DC voltage detection module is used to detect the DC voltage at both ends of the winding coil of the compressor, the output end of the variable frequency power supply module is connected to a current conversion module and an AC voltage acquisition module, the current conversion module is used to detect the stall current of the compressor, the AC voltage acquisition module is used to detect the stall voltage of the compressor, a protector is connected in series between the output end of the variable frequency power supply module and the winding coil of the compressor, when the variable frequency power supply module and the compressor form a power supply circuit, the AC voltage acquisition module is connected in parallel with the power supply circuit of the compressor, the AC voltage acquisition module can collect the voltage at the input end of the compressor before starting and the voltage at the wiring terminal after operation, and eliminate the line voltage drop loss in the detection system.

[0008] Furthermore, the DC voltage detection module includes a discharge resistor and a voltage detection chip, the discharge resistor is connected in series with the winding coil of the compressor, and the voltage detection chip is connected in parallel with the winding coil of the compressor.

[0009] Furthermore, the constant current source module includes a constant current source chip and an MCU processor, the constant current source chip is connected to the output end of the MCU processor, and the winding coil of the compressor is connected to the constant current source chip.

[0010] Furthermore, the current conversion module includes a current transformer and a current transmitter, the current transformer is connected to the variable frequency power supply module and the current transmitter respectively, and the current conversion module is provided with a plurality of current transformers, and the plurality of current transformers have different transformation ratios, so that the detection system can be compatible with the detection of compressors with various different stall currents at the same time.

[0011] Furthermore, the detection system also includes a data recording module, and the current transmitter, the constant current source module and the DC voltage detection module are all connected to the data recording module. After the current transformer converts the current when the compressor is stalled, the converted current is converted into a standard signal through the current transmitter and then sent to the data recording module. The constant current source module sends a DC current signal to the data recording module, and the DC voltage detection module sends a DC voltage signal to the data recording module.

[0012] Furthermore, the detection system also includes a constant temperature control module, which is arranged around the compressor and is used to directly adjust the temperature of the compressor. In addition, the constant temperature control module can simulate the influence of the ambient temperature of the compressor on the coil temperature in winter, summer, cold zone, subtropical and tropical environments for the compressor, so that the detection system takes into account the environmental factors of the protector and can bring additional margin, thereby helping the compressor to select a protector with a certain overload capacity.

[0013] Furthermore, the constant temperature control module includes a refrigeration unit, a heating unit, an air supply unit and a temperature control unit, the refrigeration unit, the heating unit and the air supply unit are all connected to the temperature control unit, the refrigeration unit is provided with an air-cooled refrigeration unit, the heating unit is provided with a heater, the air supply unit includes a circulating fan and an orifice plate, the orifice plate is arranged at the air outlet of the circulating fan, the orifice plate can achieve uniform air supply to the compressor, the temperature control unit is provided with a temperature control circuit, the air-cooled refrigeration unit, the heater and the circulating fan are all connected to the temperature control circuit.

[0014] Furthermore, the heater of the heating unit is a PTC heater, an ultrasonic heater or an electromagnetic induction heater.

[0015] Furthermore, the detection system also includes a capacitor selection module, the input end of the capacitor selection module is connected to the variable frequency power supply module, and the output end of the capacitor selection module is connected to the compressor, wherein the capacitor selection module is used for the operation of a single-phase compressor, the capacitor selection module includes several groups of polypropylene film capacitors, and the several groups of polypropylene film capacitors are connected in parallel. The output capacitance value of the capacitor selection module can be automatically converted freely from 1μF to 100μF according to the input value, thereby effectively being compatible with single-phase compressors that require different operating capacitances.

[0016] Furthermore, the detection system also includes a first control module, the variable frequency power supply module, the current conversion module, the AC voltage acquisition module, the constant temperature control module and the capacitor selection module are all connected to the first control module, the first control module is a PLC controller, and the first control module can control the stall operation of the compressor.

[0017] Furthermore, the detection system also includes a temperature acquisition module, which is used to collect the top temperature of the winding coil of the compressor and the shell temperature of the compressor. The temperature acquisition module is arranged in front of the compressor. The temperature acquisition module is provided with a Pt100 temperature sensor and a thermocouple temperature sensor. The Pt100 temperature sensor and the thermocouple temperature sensor are both arranged in the temperature acquisition circuit. The constant current source module, the DC voltage detection module and the temperature acquisition module are all connected to a second control module. The second control module is a PLC controller. The second control module can control the process of resistance detection of the winding coil when the compressor is blocked, that is, when the constant current source module and the DC voltage detection module complete a detection, the second control module can control the constant current source module and the DC voltage detection module to disconnect from the winding coil of the compressor respectively.

[0018] One of the beneficial effects of the present invention is that the present invention includes a variable frequency power supply module, a constant current source module and a DC voltage detection module, the output end of the variable frequency power supply module is used to connect the compressor, the constant current source module is used to input the DC current used for detection into the winding coil of the compressor, the DC voltage detection module is used to detect the DC voltage at both ends of the winding coil of the compressor, the output end of the variable frequency power supply module is connected to a current conversion module and an AC voltage acquisition module, the current conversion module is used to detect the stall current of the compressor, and the AC voltage acquisition module is used to detect the stall voltage of the compressor; wherein, the variable frequency power supply module can output AC voltages of multiple frequency specifications, and has a voltage stepless speed regulation function, can provide the compressor with voltage of any specification, and the current conversion module can convert the ultra-large current when the compressor is stalled into a small current The AC voltage acquisition module can collect the voltage at the input end before the compressor starts and the voltage at the terminal after operation, and eliminates the line voltage drop loss. When the compressor is connected to the protector, the constant current source module can input a constant DC power to the compressor winding coil when the compressor is blocked and the protector is disconnected and the AC circuit is quickly cut off. Under the power supply of the constant current source module to the winding coil, the DC voltage detection module can quickly detect the DC voltage at both ends of the compressor winding coil. The resistance value of the winding coil can be quickly converted according to the DC voltage and current. According to the change of the resistance value of the winding coil, the protector with a certain overload capacity and the most suitable for the compressor winding coil temperature protection can be accurately selected, thereby providing a detection platform that meets the requirements of the standard for the selection of compressor protectors.

[0019] A second object of the present invention is to provide a compressor stall temperature rise detection method, comprising:

[0020] Starting the variable frequency power supply module, and adjusting the output voltage and frequency of the variable frequency power supply module to the corresponding voltage and frequency required when the compressor is locked;

[0021] Within a time t (2s≤t≤5s) after the compressor is stalled and the protector is disconnected, the constant current source module inputs a DC current used for detection into the winding coil of the compressor, and the DC voltage detection module detects the DC voltage of the winding coil of the compressor;

[0022] The compressor is caused to stall N times (N>1) within a time period of T (60min≤T≤180min), and the initial value and final value of the resistance change of the winding coil when the protector is actuated each time are recorded according to the DC voltage and the DC current, and a numerical curve of the temperature rise of the winding coil is calculated and plotted based on the initial value and final value of the resistance change of the winding coil when the protector is actuated each time.

[0023] The second beneficial effect of the present invention is that the compressor stall temperature rise detection method of the present invention can take into account the stall operation and temperature rise of the compressor at the same time, the variable frequency power supply module can output voltages and frequencies of various specifications to be compatible with the operation of various compressors, the DC voltage detection module has excellent anti-strong electrical interference performance, and when the compressor stalls and the protector is disconnected, the constant current source module and the DC voltage detection module have a fast response speed, and can directly obtain the resistance change of the winding coil from the DC voltage of the winding coil and the DC current used for measurement, thereby accurately detecting the specific situation of the temperature rise of the winding coil when the compressor stalls, and drawing the coil resistance temperature rise curve within a certain period. The initial value and final value of the resistance change can intuitively reflect the change in resistance. According to the change in resistance and the resistance temperature rise curve, the protector most suitable for compressor coil temperature protection can be selected more accurately, so that the selected protector has a certain overload capacity, retains a certain margin, and has an absolutely safe and reliable limit value, thereby more accurately protecting the compressor for long-term safe and reliable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the framework of the detection system of the present invention.

[0025] Figure 2 This is a circuit diagram of the variable frequency power supply module of Example 1 of the present invention.

[0026] Figure 3 This is a circuit diagram of a constant current source module, a DC voltage detection module and a compressor according to Embodiment 1 of the present invention.

[0027] Figure 4 This is a circuit diagram of a current conversion module and an AC voltage acquisition module according to Embodiment 1 of the present invention.

[0028] Figure 5 This is a circuit diagram of a capacitor selection module according to Embodiment 2 of the present invention.

[0029] Figure 6 This is a detection flow chart of Example 3 of the present invention.

[0030] Among them: 1- variable frequency power supply module; 2- constant current source module; 3- DC voltage detection module; 4- compressor; 5- current conversion module; 6- AC voltage acquisition module; 7- protector; 8- data recording module; 9- constant temperature control module; 10- capacitor selection module; 11- first control module; 12- temperature acquisition module; 13- second control module. DETAILED DESCRIPTION

[0031] If certain words are used in the specification and claims to refer to specific components, those skilled in the art should understand that manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. As mentioned throughout the specification and claims, "including" is an open term and should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve technical problems within a certain error range and basically achieve technical effects.

[0032] In the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "horizontal", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention.

[0033] In the invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0034] The following is combined with Figures 1 to 6 The present invention is further described in detail with reference to the following specific embodiments, but is not intended to limit the present invention.

[0035] A compressor stall temperature rise detection system comprises a variable frequency power supply module 1, a constant current source module 2 and a direct current voltage detection module 3. The output end of the variable frequency power supply module 1 is used to connect a compressor 4, which is a three-phase compressor. The three-phase compressor tests the change in resistance of a U-phase winding. The three-phase compressor test standby line is connected to the end of the U-phase winding. The constant current source module 2 is used to input a direct current for detection into the winding coil of the compressor 4. The direct current voltage detection module 3 is used to detect the direct current voltage across the winding coil of the compressor 4. According to Ohm's law, the change in resistance of the winding coil with temperature can be measured by a four-wire resistance measurement method. The output end of the variable frequency power supply module 1 is connected to a current conversion module 5 and an alternating current voltage acquisition module 6. The current conversion module 5 is used to detect the stall current of the compressor 4. The alternating current voltage acquisition module 6 is used to detect the stall voltage of the compressor 4. A protector 7 is connected in series between the output end of the variable frequency power supply module 1 and the winding coil of the compressor 4.

[0036] Among them, the AC voltage acquisition module 6 is connected in parallel to the power supply circuit formed by the variable frequency power supply module 1 and the compressor 4, and can collect the voltage at the input end of the compressor 4 before starting and the voltage at the terminal after operation. The AC voltage acquisition module 6 is provided with a voltage acquisition chip, and the AC voltage acquisition module 6 can monitor and ensure the stable operation of the compressor 4 in real time. The variable frequency power supply module 1 is provided with an AC / DC conversion circuit and a DC / AC conversion circuit, so that the output voltage of the variable frequency power supply module 1 is adjustable, and the output voltage ranges from 90 to 500V, and the power supply frequency of the variable frequency power supply module 1 is adjustable, and the power supply frequency ranges from 47 to 63Hz. The constant current source module 2 includes a constant current source chip and an MCU processor. The constant current source chip is connected to the output end of the MCU processor, and the constant current source chip is connected in series with the winding coil of the compressor 4. Under the control of the MCU processor, the constant current source chip can output stable direct current to the winding coil of the compressor 4.

[0037] Preferably, the DC voltage detection module 3 includes a discharge resistor and a voltage detection chip, the discharge resistor is connected in series with the winding coil of the compressor 4 , and the voltage detection chip is connected in parallel with the winding coil of the compressor 4 .

[0038] Preferably, the current conversion module 5 includes a current transformer and a current transmitter, the current transformer is connected to the variable frequency power supply module 1 and the current transmitter respectively, the number of current transformers is several, and the current conversion module 5 is provided with current transformers with transformation ratios of 150 / 5, 100 / 5, 75 / 5, 50 / 5, and 30 / 5, so that the output current of the current conversion module 5 is controlled to 0-5A.

[0039] Preferably, the detection system also includes a data recording module 8, and the current transmitter, constant current source module 2 and DC voltage detection module 3 are all connected to the data recording module 8. After the current transformer converts the current when the compressor 4 is stalled, the converted current is converted into a standard signal through the current transmitter and then sent to the data recording module 8. The constant current source module 2 sends the DC current signal to the data recording module 8, and the DC voltage detection module 3 sends the DC voltage signal to the data recording module 8. The data recording module 8 includes a data processor and a data display. The current transmitter, constant current source module 2 and DC voltage detection module 3 are all connected to the data processor. The data processor can convert the voltage value and the current value into a resistance change curve of the winding coil, and the data display is connected to the data processor. The resistance change of the winding coil can be observed on the data display. In the process of detecting the stalled temperature rise of the compressor 4, it is often difficult to select a suitable protector 7 based only on the changes in the directly measured temperature of the top of the winding coil and the casing of the compressor 4. However, since there is a corresponding relationship between the change in the coil resistance and the change in its temperature, a better protector 7 can be selected by real-time detection of the resistance change of the winding coil, combined with the directly measured auxiliary temperature points.

[0040] Preferably, the detection system also includes a constant temperature control module 9, which is arranged around the compressor 4. The constant temperature control module 9 is used to directly adjust the temperature of the compressor 4. The temperature adjustment range of the constant temperature control module 9 is 5 to 80°C, so as to detect the temperature rise characteristics of the winding coil under various harsh temperature conditions, so that the protector 7 finally selected for temperature protection of the winding coil of the compressor 4 can operate normally under various complex environments. After determining the temperature rise characteristics of the winding coil, the protector 7 can be connected in series between the output end of the variable frequency power supply module 1 and the winding coil of the compressor 4 to verify the performance of the protector 7.

[0041] Preferably, the constant temperature control module 9 includes a refrigeration unit, a heating unit, an air supply unit and a temperature control unit. The refrigeration unit, the heating unit and the air supply unit are all connected to the temperature control unit. The refrigeration unit is provided with an air-cooled refrigeration unit. The heating unit is a PTC heater, which can stably and adjustably heat the compressor 4. The air supply unit includes a circulating fan and an orifice plate. The orifice plate is arranged at the air outlet of the circulating fan. The orifice plate can achieve uniform air supply to the compressor 4. The temperature control unit is provided with a temperature control circuit. The temperature control circuit is provided with a Pt100 platinum resistor and an MCU processor. The air-cooled refrigeration unit, the PTC heater and the circulating fan are all connected to the temperature control circuit.

[0042] When it is necessary to detect the stall temperature rise of the compressor 4 in a high temperature environment, the temperature control circuit controls the operation of the PTC heater and the circulating fan, and there is no need to start the air-cooled refrigeration unit; when it is necessary to detect the stall temperature rise of the compressor 4 in a low temperature environment, the temperature control circuit controls the operation of the air-cooled refrigeration unit, the PTC heater and the circulating fan, and the evaporator of the air-cooled refrigeration unit delivers cold air to the compressor 4 through the circulating fan.

[0043] Preferably, the detection system also includes a first control module 11, and the variable frequency power supply module 1, the current conversion module 5, the AC voltage acquisition module 6 and the constant temperature control module 9 are all connected to the first control module 11. The first control module 11 is a PLC controller, and the first control module 11 can simultaneously control the operation of the variable frequency power supply module 1, the current conversion module 5, the AC voltage acquisition module 6 and the constant temperature control module 9.

[0044] Preferably, the detection system also includes a temperature acquisition module 12, which is used to collect the temperature of the top of the winding coil of the compressor 4 and the outer shell of the compressor 4. The temperature acquisition module 12 is arranged in front of the compressor 4. The temperature acquisition module 12 is provided with a Pt100 temperature sensor and a thermocouple temperature sensor. The Pt100 temperature sensor and the thermocouple temperature sensor are arranged in the temperature acquisition circuit. The temperature acquisition module 12 can directly obtain the temperature rise of the winding coil of the compressor 4, and can also prevent the winding coil from burning by setting the outer shell temperature alarm value; and the constant current source module 2, the DC voltage detection module 3 and the temperature acquisition module 12 are all connected to the second control module 13, the second control module 13 is a PLC controller, and the second control module 13 can control the operation of the constant current source module 2, the voltage detection module 3 and the temperature acquisition module 12.

[0045] Example 2

[0046] The present embodiment is different from the embodiment 1 in that the compressor 4 is a single-phase compressor, and the test standby line of the three-phase compressor does not need to be connected to the test terminal during the detection process. The detection system also includes a capacitor selection module 10, the input end of the capacitor selection module 10 is connected to the variable frequency power supply module 1, and the output end of the capacitor selection module 10 is connected to the compressor 4, wherein the capacitor selection module 10 includes a plurality of groups of polypropylene film capacitors, and the plurality of groups of polypropylene film capacitors are connected in parallel. The output capacitance value of the capacitor selection module 10 can be automatically freely converted from 1μF to 100μF according to the input value, thereby effectively being compatible with single-phase compressors that require different operating capacitances, and the capacitor selection module 10 is also connected to the first control module 11, and the first control module 11 can control the operation and disconnection of the capacitor selection module 10, thereby realizing the flexible switching of the detection object of the stall temperature rise between the single-phase compressor and the three-phase compressor.

[0047] The other structures of this embodiment are the same as those of Embodiment 1 and will not be described again here.

[0048] Obviously, the detection system of the present invention can accurately select and verify the protector 7 with a certain overload capacity and most suitable for the winding coil temperature protection of the compressor 4 according to the change in the resistance value of the winding coil, ensuring that the selected protector 7 can work stably and reliably in the harsh environment inside the compressor, thereby providing a detection platform that complies with the standard requirements for the selection and verification of the protector 7 of the compressor 4.

[0049] Example 3

[0050] A compressor stall temperature rise detection method, comprising:

[0051] Start the variable frequency power supply module 1, and adjust the output voltage and frequency of the variable frequency power supply module 1 to the corresponding voltage and frequency required when the compressor 4 is locked;

[0052] Within a time t (t=3s) after the compressor 4 is blocked and the protector 7 is disconnected, the constant current source module 2 inputs the DC current used for detection to the winding coil of the compressor 4, and the DC voltage detection module 3 detects the DC voltage of the winding coil of the compressor 4, and the constant current source module 2 and the DC voltage detection module 3 are immediately disconnected from the compressor 4 after the time t (t=3s) to prevent the constant current source module 2 and the DC voltage detection module 3 from being burned by the AC power after the protector 7 is restored;

[0053] The compressor 4 is stalled 300 times within a time period of T (T=90 min). Based on the DC voltage of the winding coil of the compressor 4 and the DC current used for measurement, the initial and final values ​​of the resistance change of the winding coil during each action of the protector 7 are recorded, and the numerical curve of the temperature increase of the winding coil within the time period of T is converted and plotted.

[0054] Among them, the current conversion module 5 can record the stall current of the compressor 4 each time it operates within the time T, and the AC voltage acquisition module 6 can record the stall voltage of the compressor 4 each time it operates within the time T. According to the different coil materials, the temperature rise value of the winding coil of different materials each time the protector 7 operates can be obtained according to different formulas.

[0055] Obviously, the detection method of the present invention can take into account the stall operation and temperature rise of the compressor 4 at the same time. The coil resistance temperature rise curve drawn can more accurately select the protector 7 that is most suitable for the coil temperature protection of the compressor 4, so that the selected protector 7 has an absolutely safe and reliable limit value, so that the compressor 5 can operate reliably and safely for a long time.

[0056] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs can also change and modify the above embodiment. Therefore, the present invention is not limited to the above specific embodiment, and any obvious improvement, replacement or modification made by those skilled in the art on the basis of the present invention belongs to the protection scope of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A compressor stall temperature rise detection system, characterized in that: include: A variable frequency power supply module (1), a constant current source module (2) and a direct current voltage detection module (3); The output end of the variable frequency power supply module (1) is used to connect to a compressor (4), the constant current source module (2) is used to input a DC current used for detection into the winding coil of the compressor (4), and the DC voltage detection module (3) is used to detect the DC voltage at both ends of the winding coil of the compressor (4); The DC voltage detection module (3) comprises a discharge resistor and a voltage detection chip, the discharge resistor is connected in series with the winding coil of the compressor (4), and the voltage detection chip is connected in parallel with the winding coil of the compressor (4); The output end of the variable frequency power supply module (1) is connected to a current conversion module (5) and an AC voltage acquisition module (6); the current conversion module (5) is used to detect the stall current of the compressor (4); the current conversion module (5) comprises a current transformer and a current transmitter; the current transformer is connected to the variable frequency power supply module (1) and the current transmitter respectively; The AC voltage acquisition module (6) is used to detect the locked-rotor voltage of the compressor (4); a protector (7) is connected in series between the output end of the variable frequency power supply module (1) and the winding coil of the compressor (4); The detection system further comprises a data recording module (8), and the current transmitter, the constant current source module (2) and the DC voltage detection module (3) are all connected to the data recording module (8); The detection system further comprises a constant temperature control module (9), wherein the constant temperature control module (9) is arranged around the compressor (4).

2. The compressor stall temperature rise detection system according to claim 1, characterized in that: The constant temperature control module (9) comprises a refrigeration unit, a heating unit, an air supply unit and a temperature control unit, and the refrigeration unit, the heating unit and the air supply unit are all connected to the temperature control unit.

3. The compressor stall temperature rise detection system according to claim 1, characterized in that: The detection system further comprises a capacitance selection module (10), the input end of the capacitance selection module (10) being connected to the variable frequency power supply module (1), and the output end of the capacitance selection module (10) being connected to the compressor (4).

4. The compressor stall temperature rise detection system according to claim 3, characterized in that: The detection system further comprises a first control module (11), and the variable frequency power supply module (1), the current conversion module (5), the AC voltage acquisition module (6), the constant temperature control module (9) and the capacitor selection module (10) are all connected to the first control module (11).

5. The compressor stall temperature rise detection system according to claim 1, characterized in that: The detection system further comprises a temperature acquisition module (12), the temperature acquisition module (12) being used to acquire the temperature of the top of the winding coil of the compressor (4) and the outer shell of the compressor (4), the temperature acquisition module (12) being arranged in front of the compressor (4), and the constant current source module (2), the DC voltage detection module (3) and the temperature acquisition module (12) being all connected to a second control module (13).

6. A compressor stall temperature rise detection method, applied to the compressor stall temperature rise detection system according to any one of claims 1 to 5, characterized in that: include: Starting the variable frequency power supply module (1), and adjusting the output voltage and frequency of the variable frequency power supply module (1) to the corresponding voltage and frequency required when the compressor (4) is locked; Within a time t after the compressor (4) is locked and the protector (7) is disconnected, 2s≤t≤5s, the constant current source module (2) inputs a DC current used for detection into the winding coil of the compressor (4), and the DC voltage detection module (3) detects the DC voltage of the winding coil of the compressor (4); The compressor (4) is caused to stall N times within a time period T, 60 min ≤ T ≤ 180 min, N>1, and the initial value and final value of the resistance change of the winding coil when the protector (7) is actuated each time are recorded based on the DC voltage and the DC current, and a numerical curve of the temperature rise of the winding coil is calculated and drawn based on the initial value and final value of the resistance change of the winding coil when the protector (7) is actuated each time.

Images