Refrigerator and pole pair number identification method of compressor of refrigerator

Abstract

The invention discloses a refrigerator and a pole pair number identification method of a compressor of the refrigerator. Resistance parameters and inductance parameters of the compressor are identified; if the resistance parameter recognized this time and the resistance parameter recognized last time are not within the preset resistance error range, or the inductance parameter recognized this time and the inductance parameter recognized last time are not within the preset inductance error range, it is judged that the electrical parameter of the compressor changes, and the counter electromotive force coefficient of the compressor is recognized; and searching a corresponding target compressor model in a preset database according to the resistance parameter, the inductance parameter and the back electromotive force coefficient which are obtained through the identification, and taking the number of pole pairs of the target compressor model as the number of pole pairs of the compressor obtained through the identification. With the adoption of the embodiment of the invention, the pole pair number of the compressor can be intelligently matched by comparing the identified and known resistance, inductance and back electromotive force coefficients, so that the pole pair number of the compressor can be effectively identified, and the normal operation of a compressor motor is ensured.

Description

Technical Field

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

[0002] At present, refrigerator compressor inverter boards need to match different software for different compressors. There are problems such as inconsistent materials and complex management in the production and after-sales process. Therefore, the identification of compressor electrical parameters has become the biggest obstacle to the universalization of inverter control boards. In the inverter compressor control technology, the calculation of compressor torque and compressor speed during operation is usually involved. This calculation requires the value of the compressor pole pair number parameter variable to be determined in advance. At present, it is more troublesome to identify the compressor motor pole pair number in the electrical parameters. The pole pair number is a necessary parameter for the normal operation of the compressor. Failure to accurately identify the pole pair number will lead to unreasonable or inaccurate parameter settings of the compressor motor, which will cause the compressor motor to fail to operate normally. 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, in which a storage chamber is formed, and the storage chamber includes at least a refrigerating chamber and a freezing chamber;

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

[0007] The compressor is used to compress the refrigerant flowing through the refrigerator 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 coefficients 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 of the above solution, the controller is further configured as follows:

[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 of the above solution, the controller is further configured as follows:

[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 of the above solution, the controller is further configured as follows:

[0017] 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;

[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 of the above solution, the controller is further configured as follows:

[0020] According to the resistance parameter and the inductance parameter obtained by this identification, the compressor is started and controlled to rotate at a constant speed;

[0021] The rotation speed and back electromotive force of the compressor during the uniform rotation process 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 object, 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 coefficients 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 of 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 of 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 of the above solution, the identifying the inductance parameter of the compressor includes:

[0031] 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;

[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 of the above solution, the identifying the back electromotive force coefficient of the compressor includes:

[0034] According to the resistance parameter and the inductance parameter obtained by this identification, the compressor is started and controlled to rotate at a constant speed;

[0035] The rotation speed and back electromotive force of the compressor during the uniform rotation process 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 with the prior art, the pole pair number identification method of the refrigerator and its compressor disclosed in the present invention identifies the resistance parameter and inductance parameter 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, then 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 parameter, inductance parameter 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. 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, the pole pair number of the compressor can be effectively identified, and the normal operation of the compressor motor can be ensured. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

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

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

[0043] Figure 7 is a second working flow chart 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] Fig. 9 is a schematic diagram of information interaction between a refrigerator and a client provided by an embodiment of the present invention;

[0046] Fig.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 be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

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

[0050] The terms "first", "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the 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 clearly specified and limited, the terms "installed", "connected", and "connected" 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 components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0052] See also Figure 1 , Figure 1 It is a schematic diagram of the external structure of a refrigerator 100 provided in an embodiment of the present invention. The refrigerator 100 of this embodiment is approximately in the shape of a rectangular parallelepiped. The refrigerator includes a box body that defines a storage space and a plurality of door bodies arranged at the opening of the box body, wherein the door body includes a door body outer 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 insulating layer located between the door body outer shell, the door body liner, the upper end cover, and the lower end cover; usually, the insulating layer is filled with foam material. The box body is provided with a chamber, wherein the chamber includes a component storage chamber 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 : 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 door bodies, for example, Figure 1The upper storage room is provided with a double-opening door body. The door body can be pivotally arranged at the opening of the box body, and can also be opened in a drawer-like manner to achieve drawer-like storage. The refrigerator door is provided with a display screen, which is used to display prompt information and receive 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 in an embodiment of the present invention. A compressor 1, a condenser 4 and a bottom cooling fan 5 are provided in the medium-pressure cabin of the refrigerator 100. 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 cabin.

[0054] See also Figure 4 , Figure 4 It is a structural schematic 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. Among them, the compression process is: plug in the power cord of the refrigerator, when the contacts of the thermostat are connected, the compressor 1 starts to work, and the low-temperature and low-pressure refrigerant is sucked into the compressor 1, and is compressed into a high-temperature and 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 and high-pressure refrigerant gas dissipates heat through the condenser 4, 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: the saturated liquid refrigerant after condensation is filtered out of moisture and impurities by a drying filter and then flows into the capillary 3 through which the refrigerant is throttled and depressurized to become wet steam at room temperature and low pressure: the evaporation process is: 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, 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 embodiment of the present invention, since the identification of the pole pair number is the most difficult and has the worst identification accuracy in the current compressor parameter identification algorithm, the present invention intelligently matches the compressor pole pair number by comparing the known resistance, inductance and back electromotive force coefficient to solve the problem of the difficulty in identifying the compressor pole pair number.

[0056] It is worth mentioning that the motor in the compressor includes a stator and a rotor. The stator is composed of coils, that is, the conductor is stationary, and the rotor is composed of permanent magnets, which rotate. When the permanent magnet rotates, the magnetic field of the coil changes for the coil. Therefore, for a DC brushless motor constructed in this way, the induced electromotive force generated is the induced electromotive force. When the magnetic flux of the coil increases, the direction of the magnetic field generated by the induced current will hinder the increase of the magnetic flux. When the magnetic flux of the coil decreases, the direction of the magnetic field generated by the induced current will hinder the decrease of the magnetic flux. (Lenz's law) The direction of this induced electromotive force is opposite to the direction of the voltage applied to the coil, so this induced electromotive force is usually called back electromotive force in the motor. Back electromotive force 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 electromotive force. The back electromotive force constant is a parameter related to the design and structure of the motor, which is used to describe the relationship between the back electromotive force (BEM F) of the motor and the 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 movement 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 use of the motor.

[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; according to the resistance parameters, inductance parameters and back electromotive force coefficients 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.

[0058] For example, see Figure 5 , Figure 5It is the first working flow chart 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 now. At present, there are compressors of different models whose resistance and inductance are similar. Therefore, the model of the compressor cannot be accurately identified 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 identification of the back electromotive force coefficient is added in the embodiment of the present invention, 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 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 at this time, and the compressor may have been replaced. At this time, it is necessary to redetermine the number of pole pairs of the compressor 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 compressor torque and the speed during operation can be accurately adjusted in the subsequent adjustment to ensure the normal operation of the compressor motor. Exemplarily, the resistance error range is 0 to 15%, and the inductance error range is 0 to 10%.

[0059] It is worth noting that the pole pair number 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 according to 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 / 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] Exemplarily, 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, and 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 inductance identification 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 using 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, and 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 rotation speed and back electromotive force of the compressor during the uniform rotation process, so as to calculate the back electromotive force coefficient of the compressor based on the rotation speed and the back electromotive force.

[0066] Exemplarily, 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. Usually, the back electromotive force measurement of a brushless DC motor (BLDC) needs to be performed between two adjacent phases. At this uniform 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 may 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 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.

[0068] For example, see Figure 7 , Figure 7 It is a second working flow chart of the controller in the refrigerator provided in an embodiment of the present invention. The controller is also 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] Further, 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 Fig. 9 , Fig. 9: is a schematic diagram of information interaction between a refrigerator and a client provided by an embodiment of the present invention, wherein the refrigerator 100 establishes a data connection with the client 200 through a router 300 or a cloud server 400. When the refrigerator 100 and the client 200 communicate through the router 300, the refrigerator 100 and the client 200 are close to each other, and the user can view the operation status of the refrigerator placed in the kitchen or the storage status of food in the living room or room. When the refrigerator 100 and the client 200 communicate through the cloud server 400, the refrigerator 100 and the client 200 are far apart, and the user can perform data interaction with the refrigerator 100 through the APP installed in the client 200, and remote control of the refrigerator 100 can also be realized. 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 number of pole pairs 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 with the prior art, the refrigerator 100 disclosed in the present invention identifies 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; according to the resistance parameters, inductance parameters and back electromotive force coefficients 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. 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, the pole pair number of the compressor can be effectively identified, and the normal operation of the compressor motor can be ensured.

[0072] See also Fig.10 , Fig.10 1 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 implemented by a controller in a refrigerator. The method for identifying the pole pair number of a refrigerator compressor 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 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;

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

[0076] Exemplary, there are more and more models of refrigerator compressors now. At present, there are different models of compressors whose resistance and inductance are similar. Therefore, the model of the compressor cannot be accurately identified by simply identifying the inductance and resistance. 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 by laboratory pre-testing), as well as the pole pair number corresponding to this model of compressor. The resistance parameter and inductance parameter of the compressor currently identified are matched with the value identified last time. 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 / 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, and 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 compressor operation can be accurately adjusted to ensure the normal operation of the compressor motor.

[0077] Specifically, the identifying the resistance parameter of the compressor includes: acquiring 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] Exemplarily, 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, and 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: 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] Exemplarily, 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 LR circuit 0 state), and the slope of the line segment is measured. Under the premise of knowing 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 parameter and the inductance parameter obtained in this identification: obtaining the rotation speed and back electromotive force of the compressor during the uniform rotation process, so as to calculate the back electromotive force coefficient of the compressor based on the rotation speed and the back electromotive force.

[0082] Exemplarily, 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. Usually, the back electromotive force measurement of a brushless DC motor (BLDC) needs to be performed between two adjacent phases. At this uniform 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 may 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 with the prior art, the pole pair number identification method of the refrigerator compressor disclosed in the present invention identifies the resistance parameter and inductance parameter 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, then it is determined that the electrical parameters of the compressor have changed, and the back electromotive force coefficient of the compressor is identified: the corresponding target compressor model is searched in the preset database according to the resistance parameter, inductance parameter and back electromotive force coefficient obtained in this identification, 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, the pole pair number of the compressor can be effectively identified, and the normal operation of the compressor motor can be ensured.

[0085] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle 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, in which a storage chamber is formed, and the storage chamber includes at least a refrigerating chamber and a freezing chamber; A door, used for opening and closing the storage chamber; The compressor is used to compress the refrigerant flowing through the refrigerator 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 coefficients 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, characterized in that: 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, it is determined that the electrical parameters of the compressor have not changed.

3. The refrigerator according to claim 1, characterized in that: The controller is also 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, characterized in that: The controller is also configured to: 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; 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, characterized in that: The controller is also configured to: According to the resistance parameter and the inductance parameter obtained by this identification, the compressor is started and controlled to rotate at a constant speed; The rotation speed and back electromotive force of the compressor during the uniform rotation process 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 coefficients 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, characterized in that: 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, characterized in that: The identifying the resistance parameter of the compressor comprises: 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, characterized in that: The identifying the inductance parameter 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; 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, characterized in that: The identifying the back electromotive force coefficient of the compressor comprises: According to the resistance parameter and the inductance parameter obtained by this identification, the compressor is started and controlled to rotate at a constant speed; The rotation speed and back electromotive force of the compressor during the uniform rotation process 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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