Household appliance and control method thereof

Abstract

The invention discloses a household appliance and a control method thereof, and the household appliance comprises a shell, a transmission device which is arranged in the shell, is connected with a load, and is used for driving the load to rotate during transmission, a permanent magnet synchronous motor which is arranged in the shell and is used for driving the transmission device to transmit during operation, and a controller which is configured to obtain the transmission ratio of the transmission device, the actual rotating speed, the quadrature-axis current, the number of pole pairs and the quadrature-axis inductance of the permanent magnet synchronous motor are measured; determining a load fluctuation component of the quadrature-axis current according to the actual rotating speed, the quadrature-axis current and the number of pole pairs of the permanent magnet synchronous motor and the transmission ratio of the transmission device; determining a compensation value of the load voltage according to the load fluctuation component of the quadrature-axis current and the quadrature-axis inductance of the permanent magnet synchronous motor; and compensating the quadrature-axis voltage instruction of the permanent magnet synchronous motor according to the compensation value of the load voltage to suppress periodic fluctuation of the load, so that the household appliance reduces operation noise and operates stably, and the use experience of a user is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of household appliance control, and in particular to a household appliance and a control method thereof. Background Art

[0002] Household electrical appliances, such as variable frequency washing machines, generally have a transmission device, and the motor drives the load to rotate through a transmission belt. However, when such appliances are running, the load will fluctuate periodically. For example, when the weight distribution of the load is too uneven, the household appliance will be eccentric due to excessive load fluctuations, causing the washing tub to hit the wall and excessive noise. In the prior art, the washing machine detects eccentricity. If the load fluctuation is too large, it will stop running and restart after the load is evenly distributed by rotating at a certain speed. This process takes a long time and affects the working efficiency of the appliance. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the purpose of the present invention is to provide a household appliance and a control method thereof.

[0004] The present invention proposes a household appliance, which includes: a housing; a transmission device, which is arranged in the housing and connected to a load, and is used to drive the load to rotate during transmission; a permanent magnet synchronous motor, which is arranged in the housing and is used to drive the transmission device to transmit during operation; and a controller, which is configured to: obtain the transmission ratio of the transmission device, and the actual speed, quadrature-axis current, pole pair number and quadrature-axis inductance of the permanent magnet synchronous motor; determine the load fluctuation component of the quadrature-axis current according to the actual speed, quadrature-axis current and pole pair number of the permanent magnet synchronous motor, and the transmission ratio of the transmission device; determine the compensation value of the load voltage according to the load fluctuation component of the quadrature-axis current and the quadrature-axis inductance of the permanent magnet synchronous motor; and compensate the quadrature-axis voltage command of the permanent magnet synchronous motor according to the compensation value of the load voltage to suppress the periodic fluctuation of the load.

[0005] In addition, the household appliance according to the embodiment of the present invention may also have the following additional technical features:

[0006] Furthermore, when determining the load fluctuation component of the quadrature-axis current according to the actual speed, quadrature-axis current and pole pair number of the permanent magnet synchronous motor and the transmission ratio of the transmission device, the controller is configured to: determine the speed of the load according to the actual speed and pole pair number of the permanent magnet synchronous motor and the transmission ratio of the transmission device; determine the load fluctuation component of the quadrature-axis current according to the quadrature-axis current of the permanent magnet synchronous motor and the speed of the load.

[0007] Further, when determining the speed of the load according to the actual speed and pole pair number of the permanent magnet synchronous motor and the transmission ratio of the transmission device, the controller is configured as follows:

[0008]

[0009] Wherein, ω0 is the speed of the load, ω ^ is the actual speed of the permanent magnet synchronous motor, P is the number of pole pairs of the permanent magnet synchronous motor, l gr is the transmission ratio of the transmission device.

[0010] Furthermore, when determining the load fluctuation component of the quadrature-axis current based on the quadrature-axis current of the permanent magnet synchronous motor and the rotational speed of the load, the controller is configured to: use the rotational speed of the load as the center frequency, perform band-pass filtering on the quadrature-axis current of the permanent magnet synchronous motor, and obtain the load fluctuation component of the quadrature-axis current.

[0011] Furthermore, after determining the compensation value of the load voltage according to the load fluctuation component of the quadrature-axis current and the quadrature-axis inductance of the permanent magnet synchronous motor, the controller is further configured to: correct the compensation value of the load voltage to obtain a corrected compensation value of the load voltage.

[0012] Furthermore, when correcting the compensation value of the load voltage, the controller is configured to: multiply the compensation value of the load voltage by a preset correction coefficient to obtain a corrected compensation value of the load voltage.

[0013] Further, when determining the compensation value of the load voltage according to the load fluctuation component of the quadrature-axis current and the quadrature-axis inductance of the permanent magnet synchronous motor, the controller is configured to execute the following formula:

[0014]

[0015] Among them, u q is the compensation value of the load voltage, L q is the quadrature-axis inductance of the permanent magnet synchronous motor, I qgr is the load fluctuation component of the quadrature-axis current.

[0016] Furthermore, when compensating the quadrature-axis voltage command of the permanent magnet synchronous motor according to the compensation value of the load voltage, the controller is configured to: take the sum of the current quadrature-axis voltage command value of the permanent magnet synchronous motor and the compensation value of the load voltage as the compensated quadrature-axis voltage command.

[0017] Furthermore, the household electrical appliance includes a washing machine or an air conditioner.

[0018] According to the household appliance of the embodiment of the invention, the household appliance includes: a housing, a transmission device, a permanent magnet synchronous motor and a controller. The housing is used to wrap and protect the internal components of the household appliance, including the transmission device, the permanent magnet synchronous motor and the controller; the transmission device is arranged in the housing and connected to the load, and is used to drive the load to rotate during transmission; the permanent magnet synchronous motor is arranged in the housing, and is used to drive the transmission device to transmit during operation; the controller is configured to: obtain the transmission ratio of the transmission device, and the actual speed, quadrature axis current, pole pair number and quadrature axis inductance of the permanent magnet synchronous motor; determine the load fluctuation component of the quadrature axis current according to the actual speed, quadrature axis current and pole pair number of the permanent magnet synchronous motor, and the transmission ratio of the transmission device; determine the compensation value of the load voltage according to the load fluctuation component of the quadrature axis current and the quadrature axis inductance of the permanent magnet synchronous motor; compensate the quadrature axis voltage of the permanent magnet synchronous motor according to the compensation value of the load voltage, so as to suppress the periodic fluctuation of the load, reduce the operating noise of the household appliance and run smoothly, and improve the user experience. Furthermore, after determining the compensation value of the load voltage based on the load fluctuation component of the cross-axis current and the cross-axis inductance of the permanent magnet synchronous motor, the compensation value of the load voltage is corrected to obtain a corrected compensation value of the load voltage, and the cross-axis voltage command of the permanent magnet synchronous motor is compensated according to the corrected compensation value of the load voltage, thereby further improving the stability of the operation of household appliances.

[0019] In response to the above-mentioned problems, the present invention also proposes a control method for household appliances, comprising: obtaining the transmission ratio of a transmission device, and the actual speed, quadrature-axis current, pole pair number and quadrature-axis inductance of a permanent magnet synchronous motor; determining the load fluctuation component of the quadrature-axis current according to the actual speed, quadrature-axis current and pole pair number of the permanent magnet synchronous motor, and the transmission ratio of the transmission device; determining a compensation value of a load voltage according to the load fluctuation component of the quadrature-axis current and the quadrature-axis inductance of the permanent magnet synchronous motor; and compensating the quadrature-axis voltage command of the permanent magnet synchronous motor according to the compensation value of the load voltage to suppress the periodic fluctuation of the load.

[0020] According to the control method of the household appliance of the embodiment of the present invention, by obtaining the transmission ratio of the transmission device, and the actual speed, quadrature axis current, pole pair number and quadrature axis inductance of the permanent magnet synchronous motor, the load fluctuation component of the quadrature axis current is determined according to the actual speed, quadrature axis current and pole pair number of the permanent magnet synchronous motor, and the transmission ratio of the transmission device, the compensation value of the load voltage is determined according to the load fluctuation component of the quadrature axis current and the quadrature axis inductance of the permanent magnet synchronous motor, and the quadrature axis voltage command of the permanent magnet synchronous motor is compensated according to the compensation value of the load voltage, so as to suppress the periodic fluctuation of the load, reduce the operating noise of the household appliance, and run smoothly, thereby improving the user experience. Further, after determining the compensation value of the load voltage according to the load fluctuation component of the quadrature axis current and the quadrature axis inductance of the permanent magnet synchronous motor, the compensation value of the load voltage is corrected to obtain the corrected compensation value of the load voltage, and the quadrature axis voltage command of the permanent magnet synchronous motor is compensated according to the corrected compensation value of the load voltage, so as to further improve the stability of the operation of the household appliance.

[0021] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0023] Figure 1 is a schematic structural diagram of a household appliance according to an embodiment of the present invention;

[0024] Figure 2 is a flow chart for determining the load fluctuation component of the quadrature-axis current according to the actual speed, quadrature-axis current and pole pair number of the permanent magnet synchronous motor and the transmission ratio of the transmission device according to one embodiment of the present invention;

[0025] Figure 3 is a structural block diagram of load fluctuation suppression according to an embodiment of the present invention;

[0026] Figure 4 is a current waveform diagram output by a permanent magnet synchronous motor when load fluctuation suppression is not performed according to an embodiment of the present invention;

[0027] Figure 5 is a current waveform diagram output by a permanent magnet synchronous motor after load fluctuation suppression according to an embodiment of the present invention;

[0028] Figure 6 is a flow chart of a method for controlling a household appliance according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] 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.

[0030] In the description of the present invention, 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 drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0031] The terms "first" and "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 the present invention, unless otherwise specified, "plurality" means two or more.

[0032] In the description of the present invention, 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 indirectly connected 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 the present invention can be understood according to specific circumstances.

[0033] Reference below Figure 1-Figure 6 A home appliance and a control method thereof according to an embodiment of the present invention are described.

[0034] Figure 1 FIG. 1 is a schematic diagram of the structure of a household appliance according to an embodiment of the present invention. Figure 1As shown, a household appliance 10 includes: a housing 11; a transmission device 12, which is arranged in the housing and connected to the load, and is used to drive the load to rotate during transmission; a permanent magnet synchronous motor 13, which is arranged in the housing, and is used to drive the transmission device to transmit during operation; a controller 14, which is configured to: obtain the transmission ratio of the transmission device, and the actual speed, quadrature-axis current, pole pair number and quadrature-axis inductance of the permanent magnet synchronous motor; determine the load fluctuation component of the quadrature-axis current according to the actual speed, quadrature-axis current and pole pair number of the permanent magnet synchronous motor, and the transmission ratio of the transmission device; determine the compensation value of the load voltage according to the load fluctuation component of the quadrature-axis current and the quadrature-axis inductance of the permanent magnet synchronous motor; and compensate the quadrature-axis voltage command of the permanent magnet synchronous motor according to the compensation value of the load voltage to suppress the periodic fluctuation of the load.

[0035] Specifically, household appliances such as variable frequency washing machines generally have transmission devices, which drive the load to rotate under the drive of the permanent magnet synchronous motor. The transmission ratio is the ratio of the mechanical speed of the permanent magnet synchronous motor to the load speed. When the household appliance is running, the load torque will fluctuate periodically. In a cycle of the load torque fluctuation, the torques of different phases are different. The embodiment of the present invention analyzes the periodic fluctuation of the load speed and determines the compensation value of the load voltage to perform compensation control of the load fluctuation phase, that is, the periodic fluctuation of the load speed is reflected in the motor drive through the transmission ratio, and the load fluctuation phase is compensated. Control, thereby suppressing the load fluctuation within a certain range, improving the working state of the household appliance, and making it run more stably. Specifically, assuming that the fluctuation amount is a sine wave, by compensating the quadrature-axis voltage command of the permanent magnet synchronous motor, increasing the torque when the load torque is large, and reducing the torque when the load torque is small, so that it maintains a uniform speed, the household appliance can reduce the operating noise and run smoothly. In a specific embodiment, the transmission ratio of the transmission device, the pole pair number and the cross-axis inductance of the permanent magnet synchronous motor are inherent parameters of the household appliance and can be pre-stored in the controller. The actual speed of the permanent magnet synchronous motor can be obtained by sampling with a speed sensor or inferring with a position observer algorithm, and the phase current of the permanent magnet synchronous motor can be obtained by sampling with a current sensor.

[0036] In one embodiment of the present invention, Figure 2 As shown, when the load fluctuation component of the quadrature-axis current is determined according to the actual speed, quadrature-axis current and pole pair number of the permanent magnet synchronous motor, and the transmission ratio of the transmission device, the controller is configured to: determine the speed of the load according to the actual speed and pole pair number of the permanent magnet synchronous motor, and the transmission ratio of the transmission device; determine the load fluctuation component of the quadrature-axis current according to the quadrature-axis current of the permanent magnet synchronous motor and the speed of the load.

[0037] Specifically, since the ratio between the actual speed and the mechanical speed of the permanent magnet synchronous motor is the number of pole pairs of the permanent magnet synchronous motor, the speed of the load can be determined according to the actual speed and the number of pole pairs of the permanent magnet synchronous motor and the transmission ratio of the transmission device. Figure 3 As shown, when the speed of the load is determined according to the actual speed and pole pair number of the permanent magnet synchronous motor and the transmission ratio of the transmission device, the controller is configured as follows:

[0038]

[0039] Among them, ω0 is the speed of the load, ω ^ is the actual speed of the permanent magnet synchronous motor, P is the number of pole pairs of the permanent magnet synchronous motor, l gr is the transmission ratio of the transmission.

[0040] Furthermore, after determining the speed of the load, the embodiment of the present invention determines the load fluctuation component of the quadrature-axis current according to the quadrature-axis current of the permanent magnet synchronous motor and the speed of the load to determine the compensation value of the load voltage, and compensates the quadrature-axis voltage command of the permanent magnet synchronous motor according to the compensation value of the load voltage, and performs compensation control on the load fluctuation phase, thereby reflecting the periodic fluctuation of the load speed to the motor drive through the transmission ratio, suppressing the load fluctuation within a certain range, improving the working state of the household appliance, and making it run more stably.

[0041] In one embodiment of the present invention, when determining the load fluctuation component of the quadrature-axis current based on the quadrature-axis current of the permanent magnet synchronous motor and the rotational speed of the load, the controller is configured to: use the rotational speed of the load as the center frequency, perform band-pass filtering on the quadrature-axis current of the permanent magnet synchronous motor, and obtain the load fluctuation component of the quadrature-axis current.

[0042] In a specific embodiment, Figure 3 As shown in the figure, BPF (Band Pass Filter), PI (Proportional Integral Controller), SVM (Space Vector Modulation) and PM (Permanent Magnet Motor). In the embodiment of the present invention, the load speed, i.e., ω0, is used as the center frequency to modulate the quadrature axis current I of the permanent magnet synchronous motor. q Bandpass filtering is performed, that is, a sine wave with ω0 as the angular frequency is input into the BPF for bandpass filtering, and the amplitude of ω0 is extracted through the BPF, which corresponds to the load fluctuation component I of the quadrature axis current. qgr , so that the periodic fluctuation of the load speed is reflected in the motor drive, so as to q *The compensation method is to perform compensation control of the load fluctuation phase, thereby suppressing the load fluctuation within a certain range. In other implementations, the load fluctuation component of the quadrature axis current can also be extracted based on the Fourier fundamental wave extraction algorithm, which is not described here. It can be understood that since the embodiment of the present invention uses a bandpass filter, the phase delay after the compensation control is minimized and the compensation control is more accurate.

[0043] In one embodiment of the present invention, after determining the compensation value of the load voltage according to the load fluctuation component of the quadrature-axis current and the quadrature-axis inductance of the permanent magnet synchronous motor, the controller is further configured to: correct the compensation value of the load voltage to obtain a corrected compensation value of the load voltage. Specifically, when correcting the compensation value of the load voltage, the controller is configured to: multiply the compensation value of the load voltage by a preset correction coefficient to obtain a corrected compensation value of the load voltage.

[0044] Specifically, according to the load fluctuation component I qgr and the quadrature axis inductance L of the permanent magnet synchronous motor q When determining the compensation value of the load voltage, some household appliances may trigger the protection of the permanent magnet synchronous motor due to excessive compensation. Therefore, the embodiment of the present invention uses a preset correction coefficient K qgr The compensation value of the load voltage is corrected to further improve the stability of the operation of household appliances.

[0045] In a specific embodiment, Figure 3 As shown, the controller uses the correction factor K qgr Correct the compensation value of the load voltage by multiplying the compensation value of the load voltage by the correction coefficient K qgr The corrected load voltage compensation value can be obtained. It should be noted that the correction coefficient K qgr It can be pre-calibrated by experiments and stored in the controller, and different household appliances correspond to different correction coefficients.

[0046] In one embodiment of the present invention, when determining the compensation value of the load voltage according to the load fluctuation component of the quadrature-axis current and the quadrature-axis inductance of the permanent magnet synchronous motor, the controller is configured to execute the following formula:

[0047]

[0048] Among them, u q is the compensation value of the load voltage, L q is the quadrature-axis inductance of the permanent magnet synchronous motor, I qgr is the load fluctuation component of the quadrature-axis current.

[0049] Specifically, the controller calculates the load voltage compensation value u based on the above formula: qAfter that, the compensation value is compensated to the quadrature axis voltage command V of the permanent magnet synchronous motor. q * In other implementations, the compensation value of the load voltage can also be obtained by performing gain control on the load fluctuation component of the extracted quadrature-axis current through algorithms such as Fourier fundamental wave extraction, which will not be described in detail here.

[0050] In one embodiment of the present invention, when compensating the quadrature-axis voltage command of the permanent magnet synchronous motor according to the compensation value of the load voltage, the controller is configured to: use the sum of the current quadrature-axis voltage command value of the permanent magnet synchronous motor and the compensation value of the load voltage as the compensated quadrature-axis voltage command.

[0051] Specifically, if Figure 3 As shown, V q * is the current quadrature axis voltage command value of the permanent magnet synchronous motor, and the load voltage compensation value is the corrected load voltage compensation value V qshift Since the quadrature axis voltage has the same direction as the magnetic field of the permanent magnet synchronous motor, the quadrature axis voltage value is positive. Therefore, the current quadrature axis voltage command value V of the permanent magnet synchronous motor is q * and the corrected load voltage compensation value V qshift The sum is taken as the compensated quadrature-axis voltage command, that is, the compensation value of the load voltage V qshift Positive compensation to the current quadrature axis voltage command value V of the permanent magnet synchronous motor q * In order to suppress the load torque fluctuation.

[0052] In one embodiment of the present invention, household electrical appliances include but are not limited to washing machines and air conditioners, and drive systems using permanent magnet synchronous motors including transmission devices are applicable.

[0053] It should be noted that the embodiment of the present invention is applicable to the periodic suppression of load fluctuations when the permanent magnet synchronous motor is in a non-weakening magnetic control state. Under some extreme working conditions, such as when the load rotates at a high speed or when the voltage vector amplitude of the permanent magnet synchronous motor is small, that is, when the permanent magnet synchronous motor enters a deep weakening magnetic state, the cross-axis voltage accounts for a small proportion, the direct-axis voltage accounts for a large proportion, and the effect of suppressing the load periodic fluctuation is weakened. When the cross-axis voltage command of the permanent magnet synchronous motor is compensated according to the compensation value of the load voltage, the effect of suppressing the load periodic fluctuation can be improved by increasing the correction coefficient.

[0054] In practical applications, taking the washing machine system as an example, when the transmission ratio is l gr When is 10 and the number of motor pole pairs P is 2, Figure 4 is the voltage command V of the quadrature axis of the permanent magnet synchronous motor.q * When compensation is performed, the current waveform output by the permanent magnet synchronous motor shows that the output envelope is constant or has a small fluctuation; Figure 5 is the quadrature axis voltage command V for the permanent magnet synchronous motor q * After compensation, the current waveform of the permanent magnet synchronous motor output has obvious periodic fluctuations in the output envelope, and the fluctuation period is the mechanical period of the load. Figure 4 and Figure 5 It can be seen that according to the compensation value V of the load voltage qshift The quadrature axis voltage command V for the permanent magnet synchronous motor q * Compensation can suppress the periodic fluctuation of load torque. Figure 4 and Figure 5 The current waveform can be detected by Figure 3 in i u 、i v or w Any one of the currents is obtained.

[0055] According to an embodiment of the present invention, the household appliance comprises: a housing, a transmission device, a permanent magnet synchronous motor and a controller. The housing is used to wrap and protect the internal components of the household appliance, including the transmission device and the permanent magnet synchronous motor. The transmission device is arranged in the housing and connected to the load, and is used to drive the load to rotate during transmission; the permanent magnet synchronous motor is arranged in the housing, and is used to drive the transmission device to transmit during operation; the controller is configured to: obtain the transmission ratio of the transmission device, and the actual speed, quadrature axis current, pole pair number and quadrature axis inductance of the permanent magnet synchronous motor, determine the load fluctuation component of the quadrature axis current according to the actual speed, quadrature axis current and pole pair number of the permanent magnet synchronous motor, and the transmission ratio of the transmission device, determine the compensation value of the load voltage according to the load fluctuation component of the quadrature axis current and the quadrature axis inductance of the permanent magnet synchronous motor, and compensate the quadrature axis voltage command of the permanent magnet synchronous motor according to the compensation value of the load voltage, so as to suppress the periodic fluctuation of the load, reduce the operating noise of the household appliance and run smoothly, and improve the user experience. Furthermore, after determining the compensation value of the load torque based on the load fluctuation component of the quadrature-axis current and the quadrature-axis inductance of the permanent magnet synchronous motor, the compensation value of the load voltage is corrected to obtain a corrected compensation value of the load voltage, and the quadrature-axis voltage command of the permanent magnet synchronous motor is compensated according to the corrected compensation value of the load voltage, thereby further improving the stability of the operation of household appliances.

[0056] A further embodiment of the present invention also discloses a control method for household electrical appliances, such as Figure 6 As shown, the method comprises the following steps:

[0057] Step S1: obtaining the transmission ratio of the transmission device, and the actual speed, quadrature-axis current, number of pole pairs and quadrature-axis inductance of the permanent magnet synchronous motor.

[0058] Step S2: determining the load fluctuation component of the quadrature-axis current according to the actual rotation speed, quadrature-axis current and pole pair number of the permanent magnet synchronous motor and the transmission ratio of the transmission device.

[0059] Step S3: determining a compensation value of the load voltage according to the load fluctuation component of the quadrature-axis current and the quadrature-axis inductance of the permanent magnet synchronous motor.

[0060] Step S4: Compensating the quadrature-axis voltage command of the permanent magnet synchronous motor according to the compensation value of the load voltage to suppress the periodic fluctuation of the load.

[0061] In one embodiment of the present invention, the load fluctuation component of the quadrature-axis current is determined according to the actual speed, quadrature-axis current and pole pair number of the permanent magnet synchronous motor, and the transmission ratio of the transmission device, including: determining the speed of the load according to the actual speed and pole pair number of the permanent magnet synchronous motor, and the transmission ratio of the transmission device; determining the load fluctuation component of the quadrature-axis current according to the quadrature-axis current of the permanent magnet synchronous motor and the speed of the load.

[0062] In one embodiment of the present invention, the speed of the load is determined according to the actual speed and pole pair number of the permanent magnet synchronous motor and the transmission ratio of the transmission device, including:

[0063]

[0064] Among them, ω0 is the speed of the load, ω ^ is the actual speed of the permanent magnet synchronous motor, P is the number of pole pairs of the permanent magnet synchronous motor, l gr is the transmission ratio of the transmission.

[0065] In one embodiment of the present invention, the fluctuating component of the quadrature-axis current is determined based on the quadrature-axis current of the permanent magnet synchronous motor and the rotational speed of the load, including: taking the rotational speed of the load as the center frequency, performing band-pass filtering on the quadrature-axis current of the permanent magnet synchronous motor, and obtaining the load fluctuating component of the quadrature-axis current.

[0066] In one embodiment of the present invention, after determining the compensation value of the load voltage according to the load fluctuation component of the quadrature-axis current and the quadrature-axis inductance of the permanent magnet synchronous motor, the method further includes: correcting the compensation value of the load voltage to obtain a corrected compensation value of the load voltage.

[0067] In one embodiment of the present invention, the compensation value of the load voltage is corrected, including: multiplying the compensation value of the load voltage by a preset correction coefficient to obtain a corrected compensation value of the load voltage.

[0068] In one embodiment of the present invention, determining the compensation value of the load torque according to the load fluctuation component of the quadrature-axis current and the quadrature-axis inductance of the permanent magnet synchronous motor includes:

[0069]

[0070] Among them, u q is the compensation value of the load voltage, L q is the quadrature-axis inductance of the permanent magnet synchronous motor, I qgr is the load fluctuation component of the quadrature-axis current.

[0071] In one embodiment of the present invention, the quadrature-axis voltage command of the permanent magnet synchronous motor is compensated according to the compensation value of the load voltage, including: taking the sum of the current quadrature-axis voltage command value of the permanent magnet synchronous motor and the compensation value of the load voltage as the compensated quadrature-axis voltage command.

[0072] In one embodiment of the present invention, the household appliance includes a washing machine.

[0073] It should be noted that when the control method of the household appliance in the embodiment of the present invention controls the household appliance, its specific implementation method is similar to the specific implementation method of the household appliance in the embodiment of the present invention. Please refer to the description of the system part for details. In order to reduce redundancy, it will not be repeated here.

[0074] According to the control method of the household appliance of the embodiment of the present invention, by obtaining the transmission ratio of the transmission device, and the actual speed, quadrature axis current, pole pair number and quadrature axis inductance of the permanent magnet synchronous motor, the load fluctuation component of the quadrature axis current is determined according to the actual speed, quadrature axis current and pole pair number of the permanent magnet synchronous motor, and the transmission ratio of the transmission device, the compensation value of the load voltage is determined according to the load fluctuation component of the quadrature axis current and the quadrature axis inductance of the permanent magnet synchronous motor, and the quadrature axis voltage or current command of the permanent magnet synchronous motor is compensated according to the compensation value of the load voltage, so as to suppress the periodic fluctuation of the load, reduce the operating noise of the household appliance, and run smoothly, thereby improving the user experience. Further, after determining the compensation value of the load voltage according to the load fluctuation component of the quadrature axis current and the quadrature axis inductance of the permanent magnet synchronous motor, the compensation value of the load voltage is corrected to obtain the corrected compensation value of the load voltage, and the quadrature axis voltage command of the permanent magnet synchronous motor is compensated according to the corrected compensation value of the load voltage, so as to further improve the stability of the operation of the household appliance.

[0075] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0076] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A household appliance, characterized in that: include: case; A transmission device, disposed in the housing and connected to the load, for driving the load to rotate during transmission; A permanent magnet synchronous motor is disposed in the housing and is used to drive the transmission device during operation; A controller is configured to: obtain a transmission ratio of the transmission device, and an actual rotation speed, quadrature-axis current, pole pair number, and quadrature-axis inductance of the permanent magnet synchronous motor; Determining the load fluctuation component of the quadrature-axis current according to the actual speed, quadrature-axis current and pole pair number of the permanent magnet synchronous motor and the transmission ratio of the transmission device; Determining a compensation value of a load voltage according to a load fluctuation component of the quadrature-axis current and a quadrature-axis inductance of the permanent magnet synchronous motor; The quadrature-axis voltage command of the permanent magnet synchronous motor is compensated according to the compensation value of the load voltage to suppress the periodic fluctuation of the load.

2. The household appliance according to claim 1, characterized in that: When determining the load fluctuation component of the quadrature-axis current according to the actual speed, quadrature-axis current and pole pair number of the permanent magnet synchronous motor and the transmission ratio of the transmission device, the controller is configured as follows: Determining the speed of the load according to the actual speed and pole pair number of the permanent magnet synchronous motor and the transmission ratio of the transmission device; A load fluctuation component of the quadrature-axis current is determined according to the quadrature-axis current of the permanent magnet synchronous motor and the rotational speed of the load.

3. The household appliance according to claim 2, characterized in that: When determining the speed of the load according to the actual speed and pole pair number of the permanent magnet synchronous motor and the transmission ratio of the transmission device, the controller is configured as follows: Wherein, ω0 is the speed of the load, ω ^ is the actual speed of the permanent magnet synchronous motor, P is the number of pole pairs of the permanent magnet synchronous motor, l gr is the transmission ratio of the transmission device.

4. The household appliance according to claim 2, characterized in that: When determining the load fluctuation component of the quadrature-axis current according to the quadrature-axis current of the permanent magnet synchronous motor and the rotational speed of the load, the controller is configured as follows: The rotation speed of the load is taken as the center frequency, and the quadrature-axis current of the permanent magnet synchronous motor is subjected to band-pass filtering to obtain a load fluctuation component of the quadrature-axis current.

5. The household appliance according to claim 1, characterized in that: After determining the compensation value of the load voltage according to the load fluctuation component of the quadrature-axis current and the quadrature-axis inductance of the permanent magnet synchronous motor, the controller is further configured to: The compensation value of the load voltage is corrected to obtain a corrected compensation value of the load voltage.

6. The household appliance according to claim 5, characterized in that: When correcting the compensation value of the load voltage, the controller is configured as follows: The compensation value of the load voltage is multiplied by a preset correction coefficient to obtain a corrected compensation value of the load voltage.

7. The household appliance according to claim 1, characterized in that: When determining the compensation value of the load voltage according to the load fluctuation component of the quadrature-axis current and the quadrature-axis inductance of the permanent magnet synchronous motor, the controller is configured to execute the following formula: Among them, u q is the compensation value of the load voltage, L q is the quadrature-axis inductance of the permanent magnet synchronous motor, I qgr is the load fluctuation component of the quadrature-axis current.

8. The household appliance according to claim 1, characterized in that: When compensating the quadrature-axis voltage command of the permanent magnet synchronous motor according to the compensation value of the load voltage, the controller is configured as follows: The sum of the current quadrature-axis voltage command value of the permanent magnet synchronous motor and the compensation value of the load voltage is used as the compensated quadrature-axis voltage command.

9. The household appliance according to claim 1, characterized in that: The household electrical appliance includes a washing machine or an air conditioner.

10. A method for controlling a household appliance, characterized in that: include: Obtain the transmission ratio of the transmission device, as well as the actual speed, quadrature-axis current, number of pole pairs, and quadrature-axis inductance of the permanent magnet synchronous motor; Determining the load fluctuation component of the quadrature-axis current according to the actual speed, quadrature-axis current and pole pair number of the permanent magnet synchronous motor and the transmission ratio of the transmission device; Determining a compensation value of a load voltage according to a load fluctuation component of the quadrature-axis current and a quadrature-axis inductance of the permanent magnet synchronous motor; The quadrature-axis voltage command of the permanent magnet synchronous motor is compensated according to the compensation value of the load voltage to suppress the periodic fluctuation of the load.

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