A method for identifying pole pairs of refrigerator and compressor thereof

Abstract

The present invention discloses a method for identifying the pole pair number of a refrigerator and its compressor, which identifies the resistance and inductance parameters of the compressor. If the resistance parameter identified this time and the resistance parameter identified last time are not within a preset resistance error range, or if the inductance parameter identified this time and the inductance parameter identified last time are not within a preset inductance error range, it is determined that the electrical parameters of the compressor have changed, and the back electromotive force coefficient of the compressor is identified. Based on the resistance parameter, inductance parameter, and back electromotive force coefficient obtained in this identification, a corresponding target compressor model is searched in a preset database, and the pole pair number of the target compressor model is used as the pole pair number of the compressor obtained in this identification. Using the embodiment of the present invention, by comparing the identified and known resistance, inductance, and back electromotive force coefficient, the pole pair number of the compressor is intelligently matched, which can effectively identify the pole pair number of the compressor and ensure the normal operation of the compressor motor.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigerators, and in particular to a method for identifying the pole pairs of a refrigerator and a compressor thereof. Background Art

[0002] Currently, refrigerator compressor inverter boards require different software for different compressors. This leads to inconsistent materials and complex management during production and after-sales service. Therefore, identifying compressor electrical parameters is the biggest obstacle to the standardization of inverter control boards. Inverter compressor control technology typically involves calculating compressor torque and operating speed, a calculation that requires a pre-determined value for the compressor pole pair number parameter. Currently, identifying the compressor motor pole pair number within the electrical parameters is a complex task, as it is essential for proper compressor operation. Failure to accurately identify the pole pair number can lead to improper or inaccurate compressor motor parameter settings, potentially preventing the compressor motor from functioning properly. Summary of the Invention

[0003] The purpose of the embodiment of the present invention is to provide a method for identifying the pole pair number of a refrigerator and a compressor thereof, which can effectively identify the pole pair number of the compressor and ensure the normal operation of the compressor motor.

[0004] To achieve the above object, an embodiment of the present invention provides a refrigerator, comprising:

[0005] a box body, wherein a storage compartment is formed in the box body, and the storage compartment includes at least a refrigeration compartment and a freezer compartment;

[0006] A door, used for opening and closing the storage chamber;

[0007] The compressor is used to compress the refrigerant flowing through the refrigerator's refrigeration cycle to provide power for the refrigeration cycle;

[0008] The controller is configured as:

[0009] identifying resistance parameters and inductance parameters of the compressor;

[0010] If the resistance parameter identified this time and the resistance parameter identified last time are not within the preset resistance error range, or the inductance parameter identified this time and the inductance parameter identified last time are not within the preset inductance error range, it is determined that the electrical parameters of the compressor have changed, and the back electromotive force coefficient of the compressor is identified;

[0011] According to the resistance parameters, inductance parameters and back electromotive force coefficient obtained in this identification, the corresponding target compressor model is searched in the preset database, and the pole pair number of the target compressor model is used as the pole pair number of the compressor obtained in this identification.

[0012] As an improvement to the above solution, the controller is further configured to:

[0013] If the resistance parameter identified this time and the resistance parameter identified last time are within the preset resistance error range, and the inductance parameter identified this time and the inductance parameter identified last time are within the preset inductance error range, it is determined that the electrical parameters of the compressor have not changed.

[0014] As an improvement to the above solution, the controller is further configured to:

[0015] A winding DC voltage and a winding current of the compressor are obtained, and a ratio of the winding DC voltage to the winding current is calculated as a resistance parameter of the compressor.

[0016] As an improvement to the above solution, the controller is further configured to:

[0017] Giving the compressor a voltage pulse of fixed amplitude within a preset time period, and obtaining a current response curve under the voltage pulse;

[0018] The inductance parameter of the compressor is calculated according to the slope of the current response curve and the fixed amplitude of the voltage pulse.

[0019] As an improvement to the above solution, the controller is further configured to:

[0020] Starting the compressor and controlling the compressor to rotate at a constant speed according to the resistance parameter and the inductance parameter obtained in this identification;

[0021] The rotation speed and back electromotive force of the compressor during uniform rotation are obtained, so as to calculate the back electromotive force coefficient of the compressor according to the rotation speed and the back electromotive force.

[0022] To achieve the above-mentioned purpose, an embodiment of the present invention further provides a method for identifying the pole pair number of a refrigerator compressor, comprising:

[0023] identifying resistance parameters and inductance parameters of the compressor;

[0024] If the resistance parameter identified this time and the resistance parameter identified last time are not within the preset resistance error range, or the inductance parameter identified this time and the inductance parameter identified last time are not within the preset inductance error range, it is determined that the electrical parameters of the compressor have changed, and the back electromotive force coefficient of the compressor is identified;

[0025] According to the resistance parameters, inductance parameters and back electromotive force coefficient obtained in this identification, the corresponding target compressor model is searched in the preset database, and the pole pair number of the target compressor model is used as the pole pair number of the compressor obtained in this identification.

[0026] As an improvement to the above solution, the method further includes:

[0027] If the resistance parameter identified this time and the resistance parameter identified last time are within the preset resistance error range, and the inductance parameter identified this time and the inductance parameter identified last time are within the preset inductance error range, it is determined that the electrical parameters of the compressor have not changed.

[0028] As an improvement to the above solution, the identifying the resistance parameter of the compressor includes:

[0029] A winding DC voltage and a winding current of the compressor are obtained, and a ratio of the winding DC voltage to the winding current is calculated as a resistance parameter of the compressor.

[0030] As an improvement to the above solution, the identifying the inductance parameter of the compressor includes:

[0031] Giving the compressor a voltage pulse of fixed amplitude within a preset time period, and obtaining a current response curve under the voltage pulse;

[0032] The inductance parameter of the compressor is calculated according to the slope of the current response curve and the fixed amplitude of the voltage pulse.

[0033] As an improvement to the above solution, the identifying the back electromotive force coefficient of the compressor includes:

[0034] Starting the compressor and controlling the compressor to rotate at a constant speed according to the resistance parameter and the inductance parameter obtained in this identification;

[0035] The rotation speed and back electromotive force of the compressor during uniform rotation are obtained, so as to calculate the back electromotive force coefficient of the compressor according to the rotation speed and the back electromotive force.

[0036] Compared to the prior art, the present invention discloses a method for identifying the pole pair number of a refrigerator and its compressor, which identifies the resistance and inductance parameters of the compressor. If the resistance parameter identified this time and the resistance parameter identified last time are not within a preset resistance error range, or if the inductance parameter identified this time and the inductance parameter identified last time are not within a preset inductance error range, it is determined that the electrical parameters of the compressor have changed, and the back electromotive force coefficient of the compressor is identified. Based on the resistance parameter, inductance parameter, and back electromotive force coefficient obtained in this identification, the corresponding target compressor model is searched in a preset database, and the pole pair number of the target compressor model is used as the pole pair number of the compressor obtained in this identification. By using the embodiment of the present invention, by comparing the identified and known resistance, inductance, and back electromotive force coefficient, the pole pair number of the compressor is intelligently matched, which can effectively identify the pole pair number of the compressor and ensure the normal operation of the compressor motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 1 is a schematic diagram of the external structure of a refrigerator provided by an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of the internal structure of a refrigerator provided by an embodiment of the present invention;

[0039] Figure 3 This is a structural diagram of a medium-pressure cabin of a refrigerator provided by an embodiment of the present invention;

[0040] Figure 4 1 is a schematic structural diagram of a refrigeration system in a refrigerator provided by an embodiment of the present invention;

[0041] Figure 5 This is a first working flow diagram of a controller in a refrigerator provided by an embodiment of the present invention;

[0042] Figure 6 This is a schematic diagram of the inductance recognition principle provided by an embodiment of the present invention;

[0043] Figure 7 is a second working flow diagram of the controller in the refrigerator provided by an embodiment of the present invention;

[0044] Figure 8 is a third working flow diagram of the controller in the refrigerator provided by an embodiment of the present invention;

[0045] Figure 9 Schematic diagram of information interaction between a refrigerator and a client provided by an embodiment of the present invention;

[0046] Figure 10 The present invention provides a flowchart of a method for identifying the pole pair number of a refrigerator compressor.

[0047] Among them, 100, refrigerator; 200, client; 300, router; 400, cloud server; 1, compressor; 2, evaporator; 3, capillary tube; 4, condenser; 5, bottom cooling fan. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0049] In the description of this application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0050] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, features specified as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0051] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0052] See also Figure 1 , Figure 1 This is a schematic diagram of the external structure of a refrigerator 100 provided by an embodiment of the present invention. The refrigerator 100 of this embodiment has an approximately rectangular shape. The refrigerator includes a box body that defines a storage space and multiple doors provided at the opening of the box body. The door body includes a door body shell located on the outside of the box body, a door body liner located on the inside of the box body, an upper end cover, a lower end cover, and an insulation layer located between the door body shell, the door body liner, the upper end cover, and the lower end cover; generally, the insulation layer is filled with foam. The box body is provided with a cavity, wherein the cavity includes a component storage cavity for placing components in the refrigerator, such as a compressor cabin, etc., and also includes a storage space for storing food, etc. See Figure 2 , Figure 2 This is a schematic diagram of the internal structure of a refrigerator provided by an embodiment of the present invention. The storage space can be divided into multiple storage rooms. The storage rooms can be configured as refrigerators and freezers according to different uses. They can also include variable temperature rooms, vacuum drawers, moisturizing drawers, etc. Each storage room corresponds to one or more doors, such as Figure 1The upper storage compartment has a double-door body. The door can be pivotally mounted at the opening of the refrigerator body and can also be opened in a drawer-like manner to achieve drawer-style storage. The refrigerator door is equipped with a display screen for displaying prompt information and receiving user touch operations.

[0053] See also Figure 3 , Figure 3 It is a structural schematic diagram of a medium-pressure cabin of a refrigerator provided by an embodiment of the present invention. The medium-pressure cabin of the refrigerator 100 is provided with a compressor 1, a condenser 4 and a bottom cooling fan 5. The bottom cooling fan 5 is used to allow cold air to pass through the condenser 4 for heat exchange and send the heat-absorbed air to the outside of the compression cabin.

[0054] See also Figure 4 , Figure 4 It is a structural diagram of a refrigeration system in a refrigerator provided by an embodiment of the present invention, wherein the refrigeration system includes a compressor 1, an evaporator 2, a drying filter (not shown in the figure), a capillary tube 3, a condenser 4 and a gas-liquid separator (not shown in the figure). The working process of the refrigeration system includes a compression process, a condensation process, a throttling process and an evaporation process. The compression process is: plug in the power cord of the refrigerator, and when the contacts of the thermostat are connected, the compressor 1 starts to work, and the low-temperature, low-pressure refrigerant is sucked into the compressor 1, and is compressed into a high-temperature, high-pressure superheated gas in the cylinder of the compressor 1 and then discharged into the condenser 4; the condensation process is: the high-temperature, high-pressure refrigerant gas dissipates heat through the condenser 4, and the temperature continues to drop, and is gradually cooled to a saturated vapor of normal temperature and high pressure, and is further cooled to a saturated liquid, and the temperature no longer drops. The temperature at this time is called the condensation temperature, and the pressure of the refrigerant remains almost unchanged during the entire condensation process; the throttling process is as follows: The flow process is as follows: the saturated liquid refrigerant after condensation is filtered out of moisture and impurities by the drying filter and then flows into the capillary tube 3, through which the refrigerant is throttled and depressurized to become wet steam at room temperature and low pressure: the evaporation process is as follows: the wet steam at room temperature and low pressure begins to absorb heat and vaporize in the evaporator 2, which not only reduces the temperature of the evaporator 2 and its surroundings, but also turns the refrigerant into a low-temperature and low-pressure gas. The refrigerant coming out of the evaporator 2 passes through the gas-liquid separator and returns to the compressor 1 again, repeating the above process to transfer the heat in the refrigerator to the air outside the box, thereby achieving the purpose of refrigeration.

[0055] In the embodiments of the present invention, pole pair number identification is the most difficult and has the lowest accuracy in current compressor parameter identification algorithms. Therefore, by comparing the known parameters of resistance, inductance, and back-electromotive force coefficient, the present invention intelligently matches the compressor pole pair number, thus resolving the difficulty in identifying compressor pole pair number.

[0056] It's worth noting that the motor in a compressor consists of a stator and a rotor. The stator is composed of coils, meaning the conductors are stationary, while the rotor is composed of permanent magnets, which rotate. Therefore, when the permanent magnets rotate, the magnetic field of the coils changes. Therefore, for a brushless DC motor constructed in this way, the induced EMF generated is called the induced EMF. When the magnetic flux in the coil increases, the direction of the magnetic field generated by the induced current opposes the increase in magnetic flux. When the magnetic flux in the coil decreases, the direction of the magnetic field generated by the induced current opposes the decrease in magnetic flux. (Lenz's law) This induced EMF is in the opposite direction of the applied voltage to the coil, so it is commonly referred to in motors as the back EMF. The back EMF is equal to the rate of change of magnetic flux. The higher the speed, the greater the rate of change, and the greater the back EMF. The back EMF constant is a parameter related to motor design and structure that describes the relationship between the motor's back EMF (back EMF) and angular velocity. The number of pole pairs of a motor is an important parameter of the motor. The number of pole pairs refers to the number of magnetic poles on the motor core, which is usually an even number. It determines the motion characteristics and performance of the motor. If the number of pole pairs of the motor is incorrect, it may cause the motor's speed, torque and other parameters to not meet the design requirements, affecting the motor's performance.

[0057] Specifically, the controller in the refrigerator is configured to: identify the resistance parameters and inductance parameters of the compressor: if the resistance parameters identified this time and the resistance parameters identified last time are not within the preset resistance error range, or the inductance parameters identified this time and the inductance parameters identified last time are not within the preset inductance error range, then it is determined that the electrical parameters of the compressor have changed, and the back electromotive force coefficient of the compressor is identified; based on the resistance parameters, inductance parameters and back electromotive force coefficient obtained in this identification, the corresponding target compressor model is searched in a preset database, and the pole pair number of the target compressor model is used as the pole pair number of the compressor obtained in this identification.

[0058] For example, see Figure 5 , Figure 5This is the first workflow diagram of the controller in the refrigerator provided by the embodiment of the present invention, and the controller is configured to execute steps S11 to S17. There are more and more models of refrigerator compressors nowadays, and there are already different models of compressors with similar resistance and inductance. Therefore, it is not possible to accurately identify the model of the compressor by simply identifying the inductance and resistance. However, the back electromotive force coefficient and the number of pole pairs of compressors of different models are different. The embodiment of the present invention adds the identification of the back electromotive force coefficient, and determines the compressor model by the three parameters of resistance, inductance, and back electromotive force coefficient. In addition, the database in the embodiment of the present invention pre-stores several models of compressors, which correspond to the three parameters of resistance, inductance and back electromotive force coefficient (obtained through laboratory pre-testing), as well as the number of pole pairs corresponding to this model of compressor. The currently identified compressor resistance parameters and inductance parameters are matched with the values ​​identified last time. If the resistance parameters or inductance parameters exceed the error, it means that the electrical parameters of the compressor have changed, and the compressor may have been replaced. At this time, the pole pair number of the compressor needs to be re-determined to adjust the compressor torque and / or compressor speed according to the pole pair number. At this time, the back electromotive force coefficient is identified, and then the internal compressor parameter table is queried to see if it is close to the known compressor parameters. The motor with the closest parameters is selected and the pole pair number is given. In this way, during the operation of the compressor, the change in electrical parameters can be matched to the appropriate pole pair number, and then the subsequent adjustment of the compressor torque and the compressor speed during operation can be accurately adjusted to ensure the normal operation of the compressor motor. For example, the resistance error range is 0-15%, and the inductance error range is 0-10%.

[0059] It is worth noting that the pole pair identification method in the embodiment of the present invention retains the pole pair number parameter after identifying the pole pair number once. When the electrical parameters change subsequently, there is no need to match the compressor model based on the three parameters of resistance, inductance and back electromotive force coefficient again. Instead, the previously identified pole pair number is directly applied. This identification method can be applied to all refrigerators that have been shipped or not shipped.

[0060] In an embodiment of the present invention, when the identified resistance and inductance parameters and the stored parameters of the last successful identification are within the error range, it is considered that the compressor has not changed, so the previous parameters can be used directly, saving the steps of back electromotive force coefficient and pole pair number identification, and optimizing the process. Only when the two identification errors are not within the range, the complete identification and matching of resistance, inductance, back electromotive force coefficient, and pole pair number is performed. The internal compressor parameter table is queried through the identified inductance, resistance, and back electromotive force coefficient to match the corresponding compressor model, thereby obtaining the correct pole pair number, solving the problem of difficult pole pair number identification.

[0061] Specifically, the controller is further configured to: obtain a winding DC voltage and a winding current of the compressor, and calculate a ratio of the winding DC voltage to the winding current as a resistance parameter of the compressor.

[0062] For example, the identification principle of the stator resistance is: U=IR. When a DC voltage is applied to the winding, the current in the winding is inversely proportional to the resistance. The stator resistance is calculated according to this formula as the resistance parameter.

[0063] Specifically, the controller is also configured to: give the compressor a voltage pulse of fixed amplitude within a preset time period, and obtain a current response curve under the voltage pulse: calculate the inductance parameters of the compressor based on the slope of the current response curve and the fixed amplitude of the voltage pulse.

[0064] For example, see Figure 6 , Figure 6 This is a schematic diagram of the inductance identification principle provided by an embodiment of the present invention. According to the inductance formula U=L*dI / dt, U is voltage, I is current, and L is inductance. A voltage pulse with a given time of Δt (preset time period) and an amplitude of Udc (fixed amplitude), wherein Δt is very small, less than 1 / 10 of the time constant of the LR circuit. At this time, the current rises at a constant slope, and the inductance parameter is calculated with the slope Udc / L corresponding to this constant rising current (ignoring the resistance voltage drop, it can also be regarded as the starting segment corresponding to the 0 state of the LR circuit), and the slope of the line segment is measured. Under the premise of knowing Udc, the inductance parameter is obtained. As Figure 6 , V ab Represents the pulse voltage, which changes from -Vs to Vs in one cycle, I L1 Represents the current, Io is the initial current.

[0065] Specifically, the controller is also configured to: start the compressor and control the compressor to rotate at a constant speed based on the resistance parameters and the inductance parameters obtained in this identification; obtain the speed and back electromotive force of the compressor during the constant speed rotation process, so as to calculate the back electromotive force coefficient of the compressor based on the speed and the back electromotive force.

[0066] For example, the motor is allowed to rotate at a constant speed for a period of time at a certain speed (such as the rated speed), and a voltmeter is used to measure the back electromotive force (BEMF) generated at the motor terminals. Typically, the back electromotive force measurement of a brushless DC motor (BLDC) needs to be performed between two adjacent phases. At this constant speed, the measured back electromotive force value and the speed value are recorded, and the speed (rpm) is converted to angular velocity (radians / second): ω = (2π × speed) / 60. Then, using the measured back electromotive force value and the calculated angular velocity value, the ratio K = BEMF / ω between them is calculated, and this ratio is used as the back electromotive force coefficient of the compressor. It is worth noting that the back electromotive force coefficient calculation method provided in the embodiment of the present invention is only used as an example. In other embodiments, other existing back electromotive force coefficient calculation methods can also be used, all within the scope of protection of the present invention.

[0067] Specifically, the controller is also configured to: if the resistance parameter identified this time and the resistance parameter identified last time are within the preset resistance error range, and the inductance parameter identified this time and the inductance parameter identified last time are within the preset inductance error range, then it is determined that the electrical parameters of the compressor have not changed.

[0068] For example, see Figure 7 , Figure 7 This is a second working flow diagram of the controller in the refrigerator provided by an embodiment of the present invention. The controller is further configured to execute step S18 to match the currently identified resistance parameters and inductance parameters of the compressor with the values ​​identified last time. If the resistance parameters and inductance parameters are both within the allowable error range, it is considered that the electrical parameters of the compressor have not changed, and there is no need to identify the number of pole pairs.

[0069] Furthermore, the detailed working process of the above steps S11 to S18 can also be referred to Figure 8 , Figure 8 This is the third working flow diagram of the controller in the refrigerator provided by the embodiment of the present invention. If the query fails and an abnormal result is output, it may be caused by a compressor failure. The user can contact the manufacturer for compressor repair.

[0070] See also Figure 9 , Figure 93 is a schematic diagram of information interaction between a refrigerator and a client provided by an embodiment of the present invention. The refrigerator 100 establishes a data connection with the client 200 via a router 300 or a cloud server 400. When the refrigerator 100 and the client 200 communicate via the router 300, the refrigerator 100 and the client 200 are relatively close to each other, and the user can view the operating status of the refrigerator placed in the kitchen or the storage status of ingredients in the living room or room. When the refrigerator 100 and the client 200 communicate via the cloud server 400, the refrigerator 100 and the client 200 are relatively far apart, and the user can use the APP installed in the client 200 to interact with the refrigerator 100 for data, and can also remotely control the refrigerator 100. In addition, the cloud server 400 may be provided with a database in which several models of compressors are pre-stored, which correspond to the three parameters of resistance, inductance and back electromotive force coefficient (obtained through pre-testing in the laboratory), as well as the pole pair number corresponding to this model of compressor. When the controller needs to perform parameter comparison, the resistance parameters, inductance parameters and back electromotive force coefficient are uploaded to the cloud server 400 for matching, and then the cloud server 400 returns the identification result, which can save data storage space of the refrigerator 100.

[0071] Compared to the prior art, the refrigerator 100 disclosed in the present invention identifies the resistance and inductance parameters of the compressor. If the resistance parameter identified this time and the resistance parameter identified last time are not within a preset resistance error range, or if the inductance parameter identified this time and the inductance parameter identified last time are not within a preset inductance error range, then it is determined that the electrical parameters of the compressor have changed, and the back-electromotive force coefficient of the compressor is identified. Based on the resistance parameter, inductance parameter, and back-electromotive force coefficient obtained in this identification, the corresponding target compressor model is searched in a preset database, and the pole pair number of the target compressor model is used as the pole pair number of the compressor obtained in this identification. By using the embodiment of the present invention, by comparing the identified and known resistance, inductance, and back-electromotive force coefficients, the pole pair number of the compressor is intelligently matched, which can effectively identify the pole pair number of the compressor and ensure the normal operation of the compressor motor.

[0072] See also Figure 10 , Figure 10 This is a flow chart of a method for identifying the pole pair number of a refrigerator compressor provided by an embodiment of the present invention. The method for identifying the pole pair number of a refrigerator compressor is executed by a controller in a refrigerator and includes:

[0073] S1. Identifying resistance parameters and inductance parameters of the compressor;

[0074] S2. If the resistance parameter identified this time and the resistance parameter identified last time are not within a preset resistance error range, or if the inductance parameter identified this time and the inductance parameter identified last time are not within a preset inductance error range, it is determined that the electrical parameters of the compressor have changed, and the back electromotive force coefficient of the compressor is identified;

[0075] S3. Search the preset database for the corresponding target compressor model according to the resistance parameters, inductance parameters, and back electromotive force coefficients obtained in this identification, and use the pole pair number of the target compressor model as the pole pair number of the compressor obtained in this identification.

[0076] For example, there are more and more models of refrigerator compressors now, and there are already different models of compressors with similar resistance and inductance. Therefore, relying solely on the method of identifying inductance and resistance cannot accurately identify the compressor model. However, the back electromotive force coefficient and pole pair number of compressors of different models are different. In the embodiment of the present invention, the identification of the back electromotive force coefficient is added, and the compressor model is determined by the three parameters of resistance, inductance, and back electromotive force coefficient. In addition, the database in the embodiment of the present invention pre-stores several models of compressors, which correspond to the three parameters of resistance, inductance, and back electromotive force coefficient (obtained through laboratory pre-testing), as well as the pole pair number corresponding to this model of compressor. The currently identified compressor resistance parameter and inductance parameter are matched with the value of the last identification. If the resistance parameter or inductance parameter exceeds the error, it means that the electrical parameters of the compressor have changed at this time, and the compressor torque and / or compressor speed need to be adjusted according to the pole pair number. At this time, the back electromotive force coefficient is identified, and then the internal compressor parameter table is queried to see whether it is close to the known compressor parameters. The motor with the closest parameters is selected and the pole pair number is given. As a result, during the operation of the compressor, the changes in electrical parameters can be matched to the appropriate pole pair number, and the subsequent adjustment of the compressor torque and the speed during operation of the compressor can be accurately adjusted to ensure the normal operation of the compressor motor.

[0077] Specifically, the identifying the resistance parameter of the compressor includes: obtaining a winding DC voltage and a winding current of the compressor, and calculating a ratio of the winding DC voltage to the winding current as the resistance parameter of the compressor.

[0078] For example, the identification principle of the stator resistance is: U=IR. When a DC voltage is applied to the winding, the current in the winding is inversely proportional to the resistance. The stator resistance is calculated according to this formula as the resistance parameter.

[0079] Specifically, the identifying of the inductance parameters of the compressor includes: giving the compressor a voltage pulse of a fixed amplitude within a preset time period, and obtaining a current response curve under the voltage pulse; and calculating the inductance parameters of the compressor based on the slope of the current response curve and the fixed amplitude of the voltage pulse.

[0080] For example, according to the inductance formula U = L * dI / dt, where U is voltage, I is current, and L is inductance, a voltage pulse of duration Δt (preset time period) and amplitude Udc (fixed amplitude) is given, where Δt is very small, less than 1 / 10 of the LR circuit time constant. At this time, the current rises at a constant slope, and the inductance parameter is calculated using the slope Udc / L corresponding to this constant rising current (ignoring the resistance voltage drop, which can also be considered as the starting segment corresponding to the LR circuit's 0 state). The slope of this line segment is measured, and given a known Udc, the inductance parameter is obtained.

[0081] Specifically, the identifying of the back electromotive force coefficient of the compressor includes: starting the compressor and controlling the compressor to rotate at a constant speed based on the resistance parameters and the inductance parameters obtained in this identification; obtaining the speed and back electromotive force of the compressor during the constant rotation process, and calculating the back electromotive force coefficient of the compressor based on the speed and the back electromotive force.

[0082] For example, the motor is allowed to rotate at a constant speed for a period of time at a certain speed (such as the rated speed), and a voltmeter is used to measure the back electromotive force (BEMF) generated at the motor terminals. Typically, the back electromotive force measurement of a brushless DC motor (BLDC) needs to be performed between two adjacent phases. At this constant speed, the measured back electromotive force value and the speed value are recorded, and the speed (rpm) is converted to angular velocity (radians / second): ω = (2π × speed) / 60. Then, using the measured back electromotive force value and the calculated angular velocity value, the ratio K = BEMF / ω between them is calculated, and this ratio is used as the back electromotive force coefficient of the compressor. It is worth noting that the back electromotive force coefficient calculation method provided in the embodiment of the present invention is only used as an example. In other embodiments, other existing back electromotive force coefficient calculation methods can also be used, all within the scope of protection of the present invention.

[0083] Specifically, the method also includes: if the resistance parameter identified this time and the resistance parameter identified last time are within a preset resistance error range, and the inductance parameter identified this time and the inductance parameter identified last time are within a preset inductance error range, then it is determined that the electrical parameters of the compressor have not changed.

[0084] Compared to the prior art, the pole pair number identification method for a refrigerator compressor disclosed in the present invention identifies the resistance parameters and inductance parameters of the compressor; if the resistance parameter identified this time and the resistance parameter identified last time are not within a preset resistance error range, or if the inductance parameter identified this time and the inductance parameter identified last time are not within a preset inductance error range, then it is determined that the electrical parameters of the compressor have changed, and the back electromotive force coefficient of the compressor is identified: based on the resistance parameter, inductance parameter, and back electromotive force coefficient obtained in this identification, the corresponding target compressor model is searched in a preset database, and the pole pair number of the target compressor model is used as the pole pair number of the compressor obtained in this identification. Using the embodiment of the present invention, by comparing the identified and known resistance, inductance, and back electromotive force coefficient, the pole pair number of the compressor is intelligently matched, which can effectively identify the pole pair number of the compressor and ensure the normal operation of the compressor motor.

[0085] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A refrigerator, characterized in that: include: a box body, wherein a storage compartment is formed in the box body, and the storage compartment includes at least a refrigeration compartment and a freezer compartment; A door, used for opening and closing the storage chamber; The compressor is used to compress the refrigerant flowing through the refrigerator's refrigeration cycle to provide power for the refrigeration cycle; The controller is configured as: identifying resistance parameters and inductance parameters of the compressor; If the resistance parameter identified this time and the resistance parameter identified last time are not within the preset resistance error range, or the inductance parameter identified this time and the inductance parameter identified last time are not within the preset inductance error range, it is determined that the electrical parameters of the compressor have changed, and the back electromotive force coefficient of the compressor is identified; According to the resistance parameters, inductance parameters and back electromotive force coefficient obtained in this identification, the corresponding target compressor model is searched in the preset database, and the pole pair number of the target compressor model is used as the pole pair number of the compressor obtained in this identification.

2. The refrigerator according to claim 1, wherein The controller is further configured to: If the resistance parameter identified this time and the resistance parameter identified last time are within the preset resistance error range, and the inductance parameter identified this time and the inductance parameter identified last time are within the preset inductance error range, it is determined that the electrical parameters of the compressor have not changed.

3. The refrigerator according to claim 1, wherein The controller is further configured to: A winding DC voltage and a winding current of the compressor are obtained, and a ratio of the winding DC voltage to the winding current is calculated as a resistance parameter of the compressor.

4. The refrigerator according to claim 1, wherein The controller is further configured to: Giving the compressor a voltage pulse of fixed amplitude within a preset time period, and obtaining a current response curve under the voltage pulse; The inductance parameter of the compressor is calculated according to the slope of the current response curve and the fixed amplitude of the voltage pulse.

5. The refrigerator according to claim 1, wherein The controller is further configured to: Starting the compressor and controlling the compressor to rotate at a constant speed according to the resistance parameter and the inductance parameter obtained in this identification; The rotation speed and back electromotive force of the compressor during uniform rotation are obtained, so as to calculate the back electromotive force coefficient of the compressor according to the rotation speed and the back electromotive force.

6. A method for identifying the pole pair number of a refrigerator compressor, characterized in that: include: Identify the resistance and inductance parameters of the compressor: If the resistance parameter identified this time and the resistance parameter identified last time are not within the preset resistance error range, or the inductance parameter identified this time and the inductance parameter identified last time are not within the preset inductance error range, it is determined that the electrical parameters of the compressor have changed, and the back electromotive force coefficient of the compressor is identified; According to the resistance parameters, inductance parameters and back electromotive force coefficient obtained in this identification, the corresponding target compressor model is searched in the preset database, and the pole pair number of the target compressor model is used as the pole pair number of the compressor obtained in this identification.

7. The method for identifying the number of pole pairs of a refrigerator according to claim 6, wherein: The method further comprises: If the resistance parameter identified this time and the resistance parameter identified last time are within the preset resistance error range, and the inductance parameter identified this time and the inductance parameter identified last time are within the preset inductance error range, it is determined that the electrical parameters of the compressor have not changed.

8. The method for identifying the number of pole pairs of a refrigerator according to claim 6, wherein: The identifying the resistance parameter of the compressor includes: A winding DC voltage and a winding current of the compressor are obtained, and a ratio of the winding DC voltage to the winding current is calculated as a resistance parameter of the compressor.

9. The method for identifying the number of pole pairs of a refrigerator according to claim 6, wherein: The identifying the inductance parameter of the compressor includes: Giving the compressor a voltage pulse of fixed amplitude within a preset time period, and obtaining a current response curve under the voltage pulse; The inductance parameter of the compressor is calculated according to the slope of the current response curve and the fixed amplitude of the voltage pulse.

10. The method for identifying the number of pole pairs of a refrigerator according to claim 6, wherein: The identifying the back electromotive force coefficient of the compressor includes: Starting the compressor and controlling the compressor to rotate at a constant speed according to the resistance parameter and the inductance parameter obtained in this identification; The rotation speed and back electromotive force of the compressor during uniform rotation are obtained, so as to calculate the back electromotive force coefficient of the compressor according to the rotation speed and the back electromotive force.

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