Refrigerator inverter compressor motor winding temperature detection method and system

Abstract

The invention provides a refrigerator inverter compressor motor winding temperature detection method and system. The method comprises the steps that the first phase resistance and the environment temperature of a compressor motor winding are obtained; acquiring magnetic flux data of a compressor motor winding by using a variable frequency driving technology; the magnetic flux data comprises real-time magnetic flux and stable magnetic flux of the compressor motor winding at the environment temperature; obtaining the rotor temperature of the compressor motor according to the magnetic flux data; based on the first phase resistance and the environment temperature, off-line detection is conducted on the compressor motor winding through the variable frequency driving technology, and the off-line temperature of the compressor motor winding is obtained; and acquiring the temperature of the compressor motor winding based on the temperature of the compressor motor rotor and the offline temperature of the compressor motor winding so as to solve the problems that the accuracy of the obtained detection result is low and detection equipment cannot be installed in compressor equipment when the temperature of the inverter compressor motor winding is detected at present.

Description

Technical Field

[0001] The present application relates to the technical field of refrigeration equipment, and in particular to a method and system for detecting the temperature of a motor winding of a variable frequency compressor of a refrigerator. Background Art

[0002] At present, the compressors of variable-frequency refrigerators in my country generally use reciprocating compressors. The compressor pump body and the variable-frequency motor are integrated together through the motor rotor shaft, and are connected to the compressor casing through four springs. When the refrigerator is running, due to the structural characteristics of the compressor pump body and the motor integration and the compressor casing, it is difficult to accurately infer the motor winding temperature by testing the temperature of the compressor case.

[0003] At present, the methods for detecting the temperature of the variable frequency compressor motor winding include: according to the permanent magnet material of the variable frequency compressor motor, within a certain temperature range, there is a reversible demagnetization characteristic (temperature increases, magnetic flux density decreases, temperature decreases, magnetic flux density increases), and the change of magnetic flux density is detected by frequency conversion technology to obtain the motor rotor temperature. However, there is an air gap between the rotor and the stator of the compressor motor. At the same time, lubricating oil and refrigerant flow in the air gap. There is a large error between the rotor temperature and the stator temperature, resulting in a low accuracy of the detection result. The detection method also includes: pre-embedded temperature probes in the motor stator for temperature measurement. Because the integrated body composed of the refrigerator compressor pump body and the variable frequency motor is connected to the compressor housing through four springs, the integrated body of the compressor vibrates when it is started and stopped, which makes it inconvenient to install the temperature probe, and there are certain safety hazards. Therefore, the temperature measurement method using temperature probes is not currently used. Summary of the invention

[0004] The present application provides a method and system for detecting the temperature of the motor winding of a refrigerator variable frequency compressor, so as to solve the technical problem that when detecting the temperature of the motor winding of the variable frequency compressor, the detection results obtained are of low accuracy and the detection equipment cannot be installed in the compressor equipment.

[0005] The first aspect of the present application provides a method for detecting the temperature of a refrigerator variable frequency compressor motor winding, comprising:

[0006] Acquire a first phase resistance of a compressor motor winding and an ambient temperature; the first phase resistance is a phase resistance of the compressor motor winding at the ambient temperature;

[0007] Utilizing variable frequency drive technology, obtaining magnetic flux data of the compressor motor winding; the magnetic flux data includes: real-time magnetic flux and stable magnetic flux of the compressor motor winding at the ambient temperature;

[0008] According to the magnetic flux data, obtaining the compressor motor rotor temperature;

[0009] Based on the first phase resistance and the ambient temperature, the compressor motor winding is tested offline by using variable frequency drive technology to obtain the offline temperature of the compressor motor winding;

[0010] The compressor motor winding temperature is acquired based on the compressor motor rotor temperature and the offline temperature of the compressor motor winding.

[0011] In some embodiments, the step of obtaining the first phase resistance of the compressor motor winding includes:

[0012] Placing the compressor motor winding in a set environment; wherein the temperature fluctuation value in the set environment is within a set range;

[0013] Use a bridge to obtain the stator line resistance of the compressor motor;

[0014] Based on the compressor motor stator line resistance, a first phase resistance of the compressor motor winding is obtained.

[0015] In some embodiments, the compressor motor winding rotor temperature is determined by the following formula:

[0016]

[0017] Where Φ1 is the stable magnetic flux; Φ m is the real-time magnetic flux; t1 is the ambient temperature; k t is the temperature variation coefficient of magnetic flux.

[0018] In some embodiments, the step of performing offline detection on the compressor motor winding based on the first phase resistance and the ambient temperature using variable frequency drive technology to obtain the offline temperature of the compressor motor winding includes:

[0019] Using variable frequency drive technology, offline detection is performed on the compressor motor winding resistance to obtain the second phase resistance of the compressor motor winding;

[0020] Based on the first phase resistance, the second phase resistance, and the ambient temperature, an offline temperature of the compressor motor winding is obtained according to a winding resistance model.

[0021] In some embodiments, the step of performing offline detection on the compressor motor winding resistance by using variable frequency drive technology to obtain the second phase resistance of the compressor motor winding includes:

[0022] Using variable frequency drive technology, outputting a first PWM wave, driving the switch tube of the inverter to turn on, and obtaining a first current on the sampling resistor; the period of the first PWM wave is a set frequency, and the duty cycle is a first ratio;

[0023] Using variable frequency drive technology, a second PWM wave is output to drive the switch tube of the inverter to turn on, and a second current on the sampling resistor is obtained; the period of the second PWM wave is the set frequency, and the duty cycle is the second ratio;

[0024] Based on the set frequency, the first proportion, the second proportion, the first current, and the second current, the second phase resistance of the compressor motor winding is obtained.

[0025] In some embodiments, the second phase resistance is determined by the following formula:

[0026] R a =4E dc (T a1 -T a2 ) / 3(I a1 -I a2 )T;

[0027] Where, T is the set period; T a1 is the first proportion; T a2 The second largest proportion; a1 is the first current; I a2 is the second current.

[0028] In some embodiments, the winding resistance model is determined by the following formula:

[0029] R a =R1(T R +t a ) / (T R +t1);

[0030] In the formula, R a is the second phase resistance; R1 is the first phase resistance; T R is the resistance temperature constant; t a is the offline temperature of the compressor motor winding; t1 is the ambient temperature.

[0031] In some embodiments, the step of obtaining the compressor motor winding temperature based on the compressor motor rotor temperature and the offline temperature of the compressor motor winding comprises:

[0032] Based on the compressor motor rotor temperature and the offline temperature of the compressor motor winding, a compensation coefficient is obtained; the compensation coefficient is:

[0033] Δ x =(t m -t a ) / t m ;

[0034] Where, t m is the compressor motor rotor temperature, t ais the offline temperature of the compressor motor winding;

[0035] The compressor motor winding temperature is obtained based on the compressor motor rotor temperature and the compensation coefficient.

[0036] In some embodiments, the compressor motor winding temperature is determined by the following formula:

[0037] t x =(1-Δ x )t m ;

[0038] In the formula, Δ x is the compensation coefficient.

[0039] The second aspect of the present application provides a refrigerator variable frequency compressor motor winding temperature detection system, comprising:

[0040] A first acquisition module is used to acquire a first phase resistance of a compressor motor winding and an ambient temperature; the first phase resistance is a phase resistance of the compressor motor winding at the ambient temperature;

[0041] The second acquisition module is configured to acquire magnetic flux data of the compressor motor winding by using variable frequency drive technology; the magnetic flux data includes: real-time magnetic flux and stable magnetic flux of the compressor motor winding at the ambient temperature;

[0042] a third acquisition module, configured to acquire the compressor motor rotor temperature according to the magnetic flux data;

[0043] a fourth acquisition module, configured to perform offline detection on the compressor motor winding based on the first phase resistance and the ambient temperature by using a variable frequency drive technology to acquire an offline temperature of the compressor motor winding;

[0044] The fifth acquisition module is configured to acquire the compressor motor winding temperature based on the compressor motor rotor temperature and the offline temperature of the compressor motor winding.

[0045] The present application provides a method and system for detecting the temperature of a variable frequency compressor motor winding of a refrigerator, the method comprising: obtaining a first phase resistance and an ambient temperature of a compressor motor winding; the first phase resistance is the phase resistance of the compressor motor winding at the ambient temperature; using a variable frequency drive technology, obtaining magnetic flux data of the compressor motor winding; the magnetic flux data comprises: real-time magnetic flux and a stable magnetic flux of the compressor motor winding at the ambient temperature; obtaining the compressor motor rotor temperature according to the magnetic flux data; based on the first phase resistance and the ambient temperature, using a variable frequency drive technology, performing an offline detection on the compressor motor winding to obtain the offline temperature of the compressor motor winding; based on the compressor motor rotor temperature and the offline temperature of the compressor motor winding, obtaining the compressor motor winding temperature, so as to solve the problem that when the variable frequency compressor motor winding temperature is currently detected, the detection result obtained is of low accuracy and the detection device cannot be installed in the compressor device. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0047] Figure 1 This is a flow chart of the method for detecting the temperature of the motor winding of the refrigerator variable frequency compressor in this application;

[0048] Figure 2 This is a schematic diagram of testing the stator winding resistance of a motor using the bridge method in this application;

[0049] Figure 3 This is a schematic diagram of collecting the second phase resistance of the compressor motor winding using the variable frequency drive technology in this application. DETAILED DESCRIPTION

[0050] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this application.

[0051] Since in some technologies, when detecting the temperature of the variable frequency compressor motor winding, the detection result obtained is of low accuracy and the detection equipment cannot be installed in the compressor equipment, in order to solve this technical problem, the present application provides a method and system for detecting the temperature of the variable frequency compressor motor winding of a refrigerator. The method and system for detecting the temperature of the variable frequency compressor motor winding of a refrigerator are described below:

[0052] For example, the current refrigerator variable frequency compressor motor winding temperature detection method includes:

[0053] (1) First, use a bridge to measure the resistance and corresponding temperature of the compressor winding at normal temperature and stable state, recorded as R1 and t1. After the compressor runs for a period of time, measure the resistance of the winding, recorded as R2, and then calculate t2, i.e. the compressor motor winding temperature, according to the formula R2 = R1 (T + t2) / (T + t1). In the formula, T is the resistance temperature constant, which is 235 for copper wire and 225 for aluminum wire. However, this method can only detect the motor winding temperature offline when the compressor is stopped.

[0054] (2) According to the permanent magnet material of the variable frequency compressor motor, within a certain temperature range, there is a reversible demagnetization characteristic (temperature increases, magnetic flux density decreases, temperature decreases, magnetic flux density increases). The motor rotor temperature can be obtained by detecting the change in magnetic flux density using variable frequency technology. However, because there is an air gap between the compressor motor rotor and stator, and lubricating oil and refrigerant flow in the air gap, there is a large error between the rotor temperature and the stator temperature. At the same time, there is a gap between the integrated body composed of the compressor pump body and the variable frequency motor and the shell, and refrigerant flows, so it is difficult to correct the compressor motor winding temperature through the compressor shell temperature.

[0055] (3) A temperature probe is embedded in the motor stator for temperature measurement. Since the refrigerator compressor pump body and the variable frequency motor are connected to the compressor housing through four springs, the integrated body vibrates when the compressor is started and stopped. The temperature probe is inconvenient to install and there is also a safety hazard. Therefore, the refrigerator compressor cannot be measured by embedding a temperature probe.

[0056] Depend on Figure 1 It can be seen that, in view of the above problems, the first aspect of the present application provides a method for detecting the temperature of a refrigerator variable frequency compressor motor winding, comprising the following steps:

[0057] S100: Obtain the first phase resistance of the compressor motor winding and the ambient temperature; the first phase resistance is the phase resistance of the compressor motor winding at the ambient temperature; first place the variable frequency compressor at a stable ambient temperature, let it stand for a period of time, use a bridge to detect the phase resistance of the motor winding (such as: A phase resistance) in a stable state (temperature fluctuation is less than 0.5°C) and record it as R1, and the ambient temperature is the temperature t1 corresponding to the winding at this time. The above parameters can also be obtained from the compressor product specification, for example, the phase resistance of the motor winding is 2 ohms at 25°.

[0058] The step of obtaining the first phase resistance of the compressor motor winding includes the following sub-steps: S110: placing the compressor motor winding in a set environment; the temperature fluctuation value in the set environment is within a set range; the temperature fluctuation value is less than 0.5°C. S120: using a bridge to obtain the stator line resistance of the compressor motor, such as Figure 2 As shown; S130: Based on the stator line resistance of the compressor motor, obtain the first phase resistance of the compressor motor winding.

[0059] S200: Utilize the variable frequency drive technology to obtain the magnetic flux data of the compressor motor winding; the magnetic flux data includes: real-time magnetic flux and stable magnetic flux of the compressor motor winding at the ambient temperature; utilize the variable frequency drive technology to detect the magnetic flux Φ1 of the motor of the variable frequency compressor in a stable state, and the corresponding temperature is the ambient temperature t1, that is, the magnetic flux Φ1 of the motor of the variable frequency compressor at the ambient temperature t1.

[0060] S300: Acquire the compressor motor rotor temperature according to the magnetic flux data; wherein the variable frequency compressor motor rotor real-time temperature is acquired according to the variable frequency compressor motor magnetic flux and temperature dependency expression, the expression is determined by the following formula:

[0061] Φ m =Φ1{1+k t (t m -t1)};

[0062] The compressor motor winding rotor temperature is determined by the following formula:

[0063]

[0064] Where Φ1 is the stable magnetic flux; Φ m is the real-time magnetic flux, which can be detected in real time; t1 is the ambient temperature; k t is the temperature variation coefficient of magnetic flux. t Determined by the permanent magnet material, provided by the compressor manufacturer, and can be obtained from the compressor product specification.

[0065] S400: Based on the first phase resistance and the ambient temperature, the compressor motor winding is offline detected by using the variable frequency drive technology to obtain the offline temperature of the compressor motor winding; the step of performing offline detection on the compressor motor winding based on the first phase resistance and the ambient temperature by using the variable frequency drive technology to obtain the offline temperature of the compressor motor winding includes the following sub-steps:

[0066] S410: Using variable frequency drive technology, offline detection is performed on the compressor motor winding resistance to obtain the second phase resistance of the compressor motor winding; the second phase resistance is determined by the following formula:

[0067] R a =4E dc (T a1 -T a2 ) / 3(I a1 -I a2 )T;

[0068] Where, T is the set period; T a1 is the first proportion; T a2 The second largest proportion; a1 is the first current; I a2 is the second current.

[0069] The step of using the variable frequency drive technology to perform offline detection on the compressor motor winding resistance and obtain the second phase resistance of the compressor motor winding includes: S411: using the variable frequency drive technology to output a first PWM wave, drive the switch tube of the inverter to turn on, and obtain a first current on the sampling resistor; the period of the first PWM wave is a set frequency, and the duty cycle is a first proportion; S412: using the variable frequency drive technology to output a second PWM wave, drive the switch tube of the inverter to turn on, and obtain a second current on the sampling resistor; the period of the second PWM wave is a set frequency, and the duty cycle is a second proportion; output the first PWM wave through the variable frequency drive, for example, the period of the first PWM wave is 5KHz, the duty cycle is 10%, drive the switch tube of the inverter to turn on, turn on VT1, VT4, VT6, and obtain the first current I on the sampling resistor. a1 ; Then use the second PWM wave to drive the switch tube of the inverter to turn on, with a duty cycle of 15%, and continue to turn on the switch tube according to VT1, VT4, and VT6, and get the current on the sampling resistor. a2 ,like Figure 3 Said; S413: based on the set frequency, the first proportion, the second proportion, the first current, and the second current, the second phase resistance of the compressor motor winding is obtained.

[0070] Exemplarily, the conduction rule of the inverter is that one of the upper arms of the inverter is turned on (VT1, VT3, VT5), and the other two switches of the lower arm that do not correspond to the upper arm are turned on. The overall conduction mode includes: VT1, VT2, VT6; VT3, VT2, VT6; VT5, VT2, VT4.

[0071] S420: Based on the first phase resistance, the second phase resistance, and the ambient temperature, the offline temperature of the compressor motor winding is obtained according to a winding resistance model. The winding resistance model is determined by the following formula:

[0072] R a =R1(T R +t a ) / (T R +t1);

[0073] In the formula, R a is the second phase resistance; R1 is the first phase resistance; T R is the resistance temperature constant; t a is the offline temperature of the compressor motor winding; t1 is the ambient temperature. Among them, the resistance temperature constant T R The value for copper wire is 235, and the value for aluminum wire is 225.

[0074] S500: Based on the compressor motor rotor temperature and the offline temperature of the compressor motor winding, the compressor motor winding temperature is obtained. By calibrating the compressor winding real-time temperature detection using variable frequency drive technology, the influence of the air gap between the motor rotor and the stator, the flow of refrigerant, the flow of lubricating oil, etc. on the winding temperature measurement is eliminated, and the accuracy of the test result is improved.

[0075] The step of obtaining the compressor motor winding temperature based on the compressor motor rotor temperature and the offline temperature of the compressor motor winding comprises the following sub-steps:

[0076] S510: Obtain a compensation coefficient based on the compressor motor rotor temperature and the offline temperature of the compressor motor winding; the compensation coefficient is:

[0077] Δ x =(t m -t a ) / t m ;

[0078] Where, t m is the compressor motor rotor temperature, t a is the offline temperature of the compressor motor winding;

[0079] S520: Based on the compressor motor rotor temperature and the compensation coefficient, the compressor motor winding temperature is obtained. The compressor motor winding temperature is determined by the following formula:

[0080] t x =(1-Δ x )t m ;

[0081] In the formula, Δ x is the compensation coefficient.

[0082] For example, the variable frequency compressor is placed in a 43°C environment laboratory and operated according to the high ambient temperature continuous operation rule. When the compressor motor rotor temperature t a When the temperature reaches 60℃, the frequency converter stops working. x =(t m -t a ) / t m The compensation coefficient is defined as Δ1. Similarly, when the motor rotor temperature t a When reaching 70℃, the compensation coefficient Δ2 is obtained, t a When the temperature reaches 80℃, the compensation coefficient Δ3 is obtained, until the maximum temperature of the compressor motor winding is specified, the compensation coefficient Δ x . Set the compensation coefficient of each temperature section Δ x Stored in the variable frequency drive control unit, the actual operation can be based on t a =(1-Δ x )t m Get the compressor motor winding temperature, where t m At 60-70℃, use Δ1 to get the compressor motor winding temperature, t m At 70-80℃, use Δ2 to get the compressor motor winding temperature, t m When the compressor motor winding reaches its maximum temperature, use Δ x By obtaining the compressor motor winding temperature, the variable frequency compressor winding temperature can be measured in real time and accurately.

[0083] This application aims at the difficulties and shortcomings of the current temperature detection of the motor winding of the refrigerator variable frequency compressor. First, the phase resistance and corresponding temperature of the motor winding of the compressor in a stable state are measured using a bridge. Secondly, the six switch tubes of the variable frequency drive inverter and the motor winding form different conduction modes, detect the corresponding current and bus voltage, obtain the phase resistance of the motor winding by calculation, and then calculate the corresponding temperature (t2) of the winding by R2=R1(T+t2) / (T+t1). This temperature is used as a reference to calibrate the real-time temperature detection of the compressor winding using the variable frequency drive technology, eliminate the influence of the air gap between the motor rotor and the stator, the flow of refrigerant, the flow of lubricating oil, etc. on the temperature measurement of the winding, and improve the test accuracy. The motor winding temperature of the refrigerator variable frequency compressor is detected online in real time when the refrigerator is working normally, and the temperature measurement accuracy is high.

[0084] The second aspect of the present application provides a temperature detection system for a variable frequency compressor motor winding of a refrigerator, comprising: a first acquisition module for acquiring a first phase resistance and an ambient temperature of a compressor motor winding; the first phase resistance is the phase resistance of the compressor motor winding at the ambient temperature; a second acquisition module, configured to acquire magnetic flux data of the compressor motor winding using variable frequency drive technology; the magnetic flux data includes: real-time magnetic flux and stable magnetic flux of the compressor motor winding at the ambient temperature; a third acquisition module, configured to acquire the compressor motor rotor temperature according to the magnetic flux data; a fourth acquisition module, configured to perform offline detection of the compressor motor winding based on the first phase resistance and the ambient temperature using variable frequency drive technology to acquire the offline temperature of the compressor motor winding; a fifth acquisition module, configured to acquire the compressor motor winding temperature based on the compressor motor rotor temperature and the offline temperature of the compressor motor winding. The effects of the above system embodiment when running can refer to the effects of the above method embodiment, which will not be repeated here.

[0085] The above specific implementation methods further explain in detail the purpose, technical solutions and beneficial effects of the embodiments of the present application. It should be understood that the above are only specific implementation methods of the embodiments of the present application and are not used to limit the protection scope of the embodiments of the present application. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solutions of the embodiments of the present application should be included in the protection scope of the embodiments of the present application.

Claims

1. A method for detecting the temperature of a refrigerator variable frequency compressor motor winding, characterized in that: include: Acquire a first phase resistance of a compressor motor winding and an ambient temperature; the first phase resistance is a phase resistance of the compressor motor winding at the ambient temperature; Using variable frequency drive technology, obtaining magnetic flux data of the compressor motor winding; The magnetic flux data includes: real-time magnetic flux and a stable magnetic flux of the compressor motor winding at the ambient temperature; According to the magnetic flux data, obtaining the compressor motor rotor temperature; Based on the first phase resistance and the ambient temperature, the compressor motor winding is tested offline by using variable frequency drive technology to obtain the offline temperature of the compressor motor winding; The compressor motor winding temperature is acquired based on the compressor motor rotor temperature and the offline temperature of the compressor motor winding.

2. A method for detecting the temperature of a refrigerator variable frequency compressor motor winding according to claim 1, characterized in that: The step of obtaining the first phase resistance of the compressor motor winding comprises: Placing the compressor motor winding in a set environment; wherein the temperature fluctuation value in the set environment is within a set range; Use a bridge to obtain the stator line resistance of the compressor motor; Based on the compressor motor stator line resistance, a first phase resistance of the compressor motor winding is obtained.

3. A method for detecting the temperature of a refrigerator variable frequency compressor motor winding according to claim 1, characterized in that: The compressor motor winding rotor temperature is determined by the following formula: Where Φ1 is the stable magnetic flux; Φ m is the real-time magnetic flux; t1 is the ambient temperature; k t is the temperature variation coefficient of magnetic flux.

4. A method for detecting the temperature of a refrigerator variable frequency compressor motor winding according to claim 1, characterized in that: The step of performing offline detection on the compressor motor winding based on the first phase resistance and the ambient temperature by using variable frequency drive technology to obtain the offline temperature of the compressor motor winding includes: Using variable frequency drive technology, offline detection is performed on the compressor motor winding resistance to obtain the second phase resistance of the compressor motor winding; Based on the first phase resistance, the second phase resistance, and the ambient temperature, an offline temperature of the compressor motor winding is obtained according to a winding resistance model.

5. A method for detecting the temperature of a refrigerator variable frequency compressor motor winding according to claim 4, characterized in that: The step of using variable frequency drive technology to perform offline detection on the compressor motor winding resistance to obtain the second phase resistance of the compressor motor winding includes: Using variable frequency drive technology, outputting a first PWM wave, driving the switch tube of the inverter to turn on, and obtaining a first current on the sampling resistor; the period of the first PWM wave is a set frequency, and the duty cycle is a first ratio; Using variable frequency drive technology, a second PWM wave is output to drive the switch tube of the inverter to turn on, and a second current on the sampling resistor is obtained; the period of the second PWM wave is the set frequency, and the duty cycle is the second ratio; Based on the set frequency, the first proportion, the second proportion, the first current, and the second current, the second phase resistance of the compressor motor winding is obtained.

6. A method for detecting the temperature of a refrigerator variable frequency compressor motor winding according to claim 4, characterized in that: The second phase resistance is determined by the following formula: R a =4E dc (T a1 -T a2 ) / 3(I a1 -I a2 )T; In the formula, T is the set period; T a1 is the first proportion; T a2 The second largest proportion; a1 is the first current; I a2 is the second current.

7. A method for detecting the temperature of a refrigerator variable frequency compressor motor winding according to claim 4, characterized in that: The winding resistance model is determined by the following formula: R a =R1(T R +t a ) / (T R +t1); In the formula, R a is the second phase resistance; R1 is the first phase resistance; T R is the resistance temperature constant; t a is the offline temperature of the compressor motor winding; t1 is the ambient temperature.

8. A method for detecting the temperature of a refrigerator variable frequency compressor motor winding according to claim 1, characterized in that: The step of obtaining the compressor motor winding temperature based on the compressor motor rotor temperature and the offline temperature of the compressor motor winding comprises: Based on the compressor motor rotor temperature and the offline temperature of the compressor motor winding, a compensation coefficient is obtained; the compensation coefficient is: Δ x =(t m -t a ) / t m ; Where, t m is the compressor motor rotor temperature, t a is the offline temperature of the compressor motor winding; The compressor motor winding temperature is obtained based on the compressor motor rotor temperature and the compensation coefficient.

9. A method for detecting the temperature of a refrigerator variable frequency compressor motor winding according to claim 1, characterized in that: The compressor motor winding temperature is determined by the following formula: t x =(1-Δ x )t m ; In the formula, Δ x is the compensation coefficient.

10. A refrigerator variable frequency compressor motor winding temperature detection system, characterized in that: include: A first acquisition module is used to acquire a first phase resistance of a compressor motor winding and an ambient temperature; the first phase resistance is a phase resistance of the compressor motor winding at the ambient temperature; A second acquisition module is configured to acquire magnetic flux data of the compressor motor winding using variable frequency drive technology; The magnetic flux data includes: real-time magnetic flux and a stable magnetic flux of the compressor motor winding at the ambient temperature; a third acquisition module, configured to acquire the compressor motor rotor temperature according to the magnetic flux data; a fourth acquisition module, configured to perform offline detection on the compressor motor winding based on the first phase resistance and the ambient temperature by using a variable frequency drive technology to acquire an offline temperature of the compressor motor winding; The fifth acquisition module is configured to acquire the compressor motor winding temperature based on the compressor motor rotor temperature and the offline temperature of the compressor motor winding.

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