阅读说明：本技术 弱磁控制方法、弱磁控制装置、电机驱动器及家用电器 (Weak magnetic control method, weak magnetic control device, motor driver and household appliance ) 是由 詹瀚林 霍军亚 于 2020-12-30 设计创作，主要内容包括：本申请实施例公开了一种弱磁控制方法、弱磁控制装置、电机驱动器及家用电器,其中,方法包括：基于输入电压的相位、电机的给定转速和所述电机的估计转速,确定出所述电机的q轴给定电流；基于所述电机的运行频率、逆变电路的输出电压幅值和所述逆变电路的最大输出电压,确定出所述电机的d轴给定电流；基于所述电机的估计角度、所述q轴给定电流、所述d轴给定电流、q轴实际电流和d轴实际电流,控制所述电机运行。(The embodiment of the application discloses a weak magnetic control method, a weak magnetic control device, a motor driver and a household appliance, wherein the method comprises the following steps: determining a q-axis given current of the motor based on a phase of an input voltage, a given rotation speed of the motor and an estimated rotation speed of the motor; determining d-axis given current of the motor based on the operating frequency of the motor, the output voltage amplitude of an inverter circuit and the maximum output voltage of the inverter circuit; and controlling the motor to operate based on the estimated angle of the motor, the q-axis given current, the d-axis given current, the q-axis actual current and the d-axis actual current.)

1. A flux-weakening control method is characterized by comprising the following steps:

determining a q-axis given current of the motor based on a phase of an input voltage, a given rotation speed of the motor and an estimated rotation speed of the motor;

determining d-axis given current of the motor based on the operating frequency of the motor, the output voltage amplitude of an inverter circuit and the maximum output voltage of the inverter circuit;

and controlling the motor to operate based on the estimated angle of the motor, the q-axis given current, the d-axis given current, the q-axis actual current and the d-axis actual current.

2. The method of claim 1, wherein determining a d-axis given current of the motor based on the operating frequency of the motor, the magnitude of the output voltage of the inverter circuit, and the maximum output voltage of the inverter circuit comprises:

determining an integral control coefficient based on the operating frequency of the motor;

and determining q-axis given current of the motor based on the determined integral control coefficient, the output voltage amplitude of the inverter circuit and the maximum output voltage of the inverter circuit.

3. The method of claim 2, wherein determining an integral control coefficient based on the operating frequency of the motor comprises:

and under the condition that the running frequency of the motor is less than or equal to the set frequency, determining that the integral control coefficient is zero.

4. The method of claim 2, wherein determining an integral control coefficient based on the operating frequency of the motor comprises:

and under the condition that the operating frequency of the motor is greater than a set frequency, determining the integral control coefficient based on the operating state of the motor.

5. The method of claim 4, wherein determining the integral control coefficient based on the operating condition of the motor in the case where the operating frequency of the motor is greater than a set frequency comprises one of:

under the condition that the motor is in a first running state, determining the integral control coefficient based on a set function corresponding to the running frequency of the motor;

under the condition that the motor is in a second operation state, determining the integral control coefficient based on a set function corresponding to the operation frequency of the motor and based on a weak magnetic compensation value; wherein the content of the first and second substances,

the first running state represents that the motor runs stably; the second operating state characterizes the motor up-speed or down-speed.

6. The method of claim 1, wherein determining the q-axis given current of the motor based on the phase of the input voltage, the given speed of the motor, and the estimated speed of the motor comprises:

determining a given torque of the motor based on a phase of an input voltage, a given rotation speed of the motor, and an estimated rotation speed of the motor;

determining q-axis given current of the motor based on a set calculation formula of the q-axis given current and given torque of the motor; wherein the set calculation formula of the q-axis given current is as follows:

i_{q_ref}characterizing the q-axis given current; t is_eCharacterizing a given torque of the electric machine; p represents the number of pole pairs of the motor; k is a radical of_TCharacterizing a back electromotive force of the motor; i.e. i_dCharacterizing a d-axis actual current of the motor; l is_dCharacterizing a d-axis inductance of the motor; l is_qCharacterizing a q-axis inductance of the electric machine.

7. A field weakening control device, comprising:

a first determination unit for determining a q-axis given current of the motor based on a phase of an input voltage, a given rotation speed of the motor, and an estimated rotation speed of the motor;

the second determining unit is used for determining d-axis given current of the motor based on the operation parameters of the compressor, the output voltage amplitude of the inverter circuit and the maximum output voltage of the inverter circuit;

and the control unit is used for controlling the motor to operate based on the estimated angle of the motor, the q-axis given current, the d-axis given current, the q-axis actual current and the d-axis actual current.

8. A motor driver, comprising: a processor and a memory for storing a computer program capable of running on the processor,

wherein the processor is adapted to perform the steps of the method of any one of claims 1 to 6 when running the computer program.

9. A household appliance, characterized in that it comprises: a motor driver, a motor, a processor and a memory for storing a computer program capable of running on the processor,

wherein the processor is adapted to perform the steps of the method of any one of claims 1 to 6 when running the computer program.

10. A storage medium having a computer program stored thereon, the computer program, when being executed by a processor, realizing the steps of the method of any one of claims 1 to 6.

Technical Field

The application relates to the field of variable frequency driving, in particular to a weak magnetic control method, a weak magnetic control device, a motor driver and a household appliance.

Background

In the related art, a driving system without an electrolytic capacitor is generally used for driving a motor of an air conditioner to operate, and the driving system without the electrolytic capacitor drives the motor to operate in a deep weak magnetic area in order to ensure the stable operation of the motor because the voltage fluctuation of a bus is large, but the working current of the motor is large, so that the loss of the motor is large, and the efficiency of the motor is reduced.

Disclosure of Invention

In view of this, it is desirable to provide a weak magnetic control method, a weak magnetic control apparatus, a motor driver and a household appliance in an embodiment of the present application, so as to solve a technical problem in the related art that when a motor operates in a deep weak magnetic region, the efficiency of the motor is reduced due to a large working current of the motor.

In order to achieve the purpose, the technical scheme of the application is realized as follows:

the embodiment of the application provides a flux weakening control method, which comprises the following steps:

determining a q-axis given current of the motor based on a phase of an input voltage, a given rotation speed of the motor and an estimated rotation speed of the motor;

determining d-axis given current of the motor based on the operating frequency of the motor, the output voltage amplitude of an inverter circuit and the maximum output voltage of the inverter circuit;

and controlling the motor to operate based on the estimated angle of the motor, the q-axis given current, the d-axis given current, the q-axis actual current and the d-axis actual current.

In the foregoing solution, the determining a d-axis given current of the motor based on the operating frequency of the motor, the output voltage amplitude of the inverter circuit, and the maximum output voltage of the inverter circuit includes:

determining an integral control coefficient based on the operating frequency of the motor;

and determining q-axis given current of the motor based on the determined integral control coefficient, the output voltage amplitude of the inverter circuit and the maximum output voltage of the inverter circuit.

In the foregoing solution, the determining an integral control coefficient based on the operating frequency of the motor includes:

and under the condition that the running frequency of the motor is less than or equal to the set frequency, determining that the integral control coefficient is zero.

In the foregoing solution, the determining an integral control coefficient based on the operating frequency of the motor includes:

and under the condition that the operating frequency of the motor is greater than a set frequency, determining the integral control coefficient based on the operating state of the motor.

In the foregoing solution, when the operating frequency of the motor is greater than a set frequency, determining the integral control coefficient based on the operating state of the motor includes one of:

under the condition that the motor is in a first running state, determining the integral control coefficient based on a set function corresponding to the running frequency of the motor;

under the condition that the motor is in a second operation state, determining the integral control coefficient based on a set function corresponding to the operation frequency of the motor and based on a weak magnetic compensation value; wherein the content of the first and second substances,

the first running state represents that the motor runs stably; the second operating state characterizes the motor up-speed or down-speed.

In the foregoing solution, the determining a q-axis given current of the motor based on the phase of the input voltage, the given rotation speed of the motor, and the estimated rotation speed of the motor includes:

determining a given torque of the motor based on a phase of an input voltage, a given rotation speed of the motor, and an estimated rotation speed of the motor;

determining q-axis given current of the motor based on a set calculation formula of the q-axis given current and given torque of the motor; wherein the set calculation formula of the q-axis given current is as follows:

i_{q_ref}characterizing the q-axis given current; t is_eCharacterizing a given torque of the electric machine; p represents the number of pole pairs of the motor; k is a radical of_TCharacterizing a back electromotive force of the motor; i.e. i_dCharacterizing a d-axis actual current of the motor; l is_dCharacterizing a d-axis inductance of the motor; l is_qCharacterizing a q-axis inductance of the electric machine.

The embodiment of the present application further provides a field weakening control device, including:

a first determination unit for determining a q-axis given current of the motor based on a phase of an input voltage, a given rotation speed of the motor, and an estimated rotation speed of the motor;

the second determining unit is used for determining d-axis given current of the motor based on the operation parameters of the compressor, the output voltage amplitude of the inverter circuit and the maximum output voltage of the inverter circuit;

and the control unit is used for controlling the motor to operate based on the estimated angle of the motor, the q-axis given current, the d-axis given current, the q-axis actual current and the d-axis actual current.

An embodiment of the present application further provides a motor driver, including: a processor and a memory for storing a computer program capable of running on the processor,

when the processor is used for running the computer program, the steps of any one of the flux weakening control methods are executed.

An embodiment of the present application further provides a household appliance, including: a motor driver, a motor, a processor and a memory for storing a computer program capable of running on the processor,

when the processor is used for running the computer program, the steps of any one of the flux weakening control methods are executed.

The embodiment of the present application further provides a storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the steps of any one of the above-mentioned flux weakening control methods.

According to the method, the q-axis given current of the motor is determined based on the phase of the input voltage, the given rotating speed of the motor and the estimated rotating speed of the motor; determining d-axis given current of the motor based on the operating frequency of the motor, the output voltage amplitude of an inverter circuit and the maximum output voltage of the inverter circuit; and controlling the motor to operate based on the estimated rotating speed, the q-axis given current, the d-axis given current, the q-axis actual current and the d-axis actual current.

Compared with the scheme that the motor is controlled to operate in the deep flux weakening region by adopting the fixed flux weakening current in the prior art, the scheme provided by the embodiment of the application can dynamically adjust the d-axis given current of the motor based on the operation frequency of the motor, and improves the flexibility of flux weakening current control while ensuring the stable operation of the motor; when the operating frequency of the motor is lower, the operating speed of the motor is lower, the flux weakening depth of the motor can be reduced by reducing the d-axis given current of the motor, so that the working current of the motor is reduced, the loss of the motor is reduced, and the efficiency of the motor is improved.

Drawings

Fig. 1 is a topological structure diagram of a motor driving apparatus without an electrolytic capacitor provided in the related art;

fig. 2 is a schematic diagram of an implementation flow of a flux-weakening control method provided in an embodiment of the present application;

fig. 3 is a schematic diagram of a motor driver for performing field weakening control on a motor according to an embodiment of the present application;

fig. 4 is a schematic flow chart of implementation of determining a d-axis given current of a motor in a field weakening control method provided in an embodiment of the present application;

fig. 5 is a graph illustrating a variation between an operating frequency and an integral control coefficient of a motor according to an embodiment of the present disclosure;

fig. 6 is a schematic structural diagram of a motor control device according to an embodiment of the present disclosure;

fig. 7 is a schematic diagram of a hardware composition structure of a household appliance according to an embodiment of the present application.

Detailed Description

In the related art, the motor is driven to operate by a motor driving device without an electrolytic capacitor. Referring to fig. 1, the motor driving apparatus without an electrolytic capacitor includes: the motor driver comprises a filtering module, a rectifying module, a direct current bus energy storage module, an inversion module and a control module. The filtering module consists of an inductor Lg, the rectifying module consists of diodes D1-D4, the direct current bus energy storage module consists of a film capacitor C1, and the inverting module consists of a power switch tube (IGBT) S1-S6.

The control module is used for setting the rotating speed based on the motorInput voltage u_inDC bus voltage u of motor_dcThree-phase symmetrical sine alternating current i of motor_abcAnd (3) outputting a Pulse Width Modulation (PWM) signal to the inverter module according to the parameters so as to drive the motor to operate, thereby realizing the field weakening control of the motor. The motor is a permanent-magnet synchronous motor (PMSM).

In the related art, no matter what operation state the motor is, the control module in the motor driving device without the electrolytic capacitor performs field weakening control on the motor by using the same control coefficient. The field weakening control is to adjust field weakening current of the motor based on a given voltage and an actual voltage of the motor, for example, to increase d-axis current and decrease q-axis current of the motor, so as to reduce magnetic flux of the motor and increase the rotation speed of the motor.

Because the bus voltage fluctuation of the motor in the motor driving device without the electrolytic capacitor is large, in order to ensure that the motor stably runs under the conditions of high speed, heavy load, speed rising or speed falling and the like, the driving device without the electrolytic capacitor drives the motor to run in a deep weak magnetic area; however, when the motor operates at a low speed, only a small weak magnetic current is needed to ensure the stability of the motor system, and when the motor operates at a low speed, the same weak magnetic current as that of the motor operating at a high speed is still adopted to carry out deep weak magnetic on the motor, so that the working current of the motor is overlarge, the loss of the motor is increased, and further the efficiency of the motor is reduced.

In order to solve the above technical problem, an embodiment of the present application provides a flux weakening control method: determining a q-axis given current of the motor based on a phase of an input voltage, a given rotation speed of the motor and an estimated rotation speed of the motor; determining d-axis given current of the motor based on the operating frequency of the motor, the output voltage amplitude of an inverter circuit and the maximum output voltage of the inverter circuit; and controlling the motor to operate based on the estimated rotating speed, the q-axis given current, the d-axis given current, the q-axis actual current and the d-axis actual current.

Compared with the scheme that the motor is controlled to operate in the deep flux weakening region by adopting the fixed flux weakening current in the prior art, the scheme provided by the embodiment of the application can dynamically adjust the d-axis given current of the motor based on the operation frequency of the motor, and improves the flexibility of flux weakening current control while ensuring the stable operation of the motor; when the operating frequency of the motor is lower, the operating speed of the motor is lower, the flux weakening depth of the motor can be reduced by reducing the d-axis given current of the motor, so that the working current of the motor is reduced, the loss of the motor is reduced, and the efficiency of the motor is improved.

The technical solution of the present application is further described in detail with reference to the drawings and specific embodiments of the specification.

Fig. 2 shows an implementation flow diagram of a flux weakening control method provided by an embodiment of the present application. In the embodiment of the application, the main execution body of the field weakening control method is a motor driver or a household appliance comprising the motor driver and a motor, and the household appliance comprises an air conditioner. Wherein the motor drive comprises modules as shown in figure 1.

The embodiment of the application improves a flux weakening control method, and with reference to fig. 2, the flux weakening control method provided by the embodiment of the application comprises the following steps:

s201: determining a q-axis given current of the motor based on a phase of an input voltage, a given rotation speed of the motor, and an estimated rotation speed of the motor.

The following describes the implementation process of the field weakening control on the motor in detail with reference to fig. 3:

obtaining three-phase symmetrical sine alternating current i of the motor_abcIn the case of three-phase symmetrical sinusoidal alternating current i to the motor_abcClark conversion is carried out to obtain the alpha-axis current i of the motor_αAnd beta axis current i of the motor_β(ii) a For alpha axis current i_αAnd beta axis current i_βCarrying out Park conversion to obtain d-axis actual current i of the motor_dAnd q-axis actual current i of the motor_q。

Estimating an estimated angle of a rotor of an electric machine based on a relevant parameter of the electric machineAnd estimating the rotational speedRelevant parameters of the motor include: alpha axis current i of motor_αBeta axis current i of the motor_βAlpha-axis voltage u of motor_αBeta axis voltage u of motor_βPermanent magnet flux linkage psi for an electric machine_fD-axis actual current i of the motor_dQ-axis actual current i of the motor_qAnd the resistance of the motor, etc.

Using a phase-locked loop based on the input voltage u_inDetermining the phase θ of the input voltage_g(ii) a Phase theta based on input voltage using a current waveform generator_gGenerating a first current W_f。

At the determined phase theta of the input voltage_gEstimated angle of motorAnd estimating the rotational speedBased on the phase θ of the input voltage_gA first current W_fEstimated angle of motorAnd estimating the rotational speedDetermining a q-axis set current i of the motor_{q_ref}。

In some embodiments, a q-axis set current i of the motor is determined_{q_ref}The method comprises the following steps:

determining a given torque of the motor based on a phase of an input voltage, a given rotation speed of the motor, and an estimated rotation speed of the motor;

determining q-axis given current of the motor based on a set calculation formula of the q-axis given current and given torque of the motor; wherein the set calculation formula of the q-axis given current is as follows:

i_{q_ref}characterizing the q-axis given current; t is_eCharacterizing a given torque of the electric machine; p represents the number of pole pairs of the motor; k is a radical of_TCharacterizing a back electromotive force of the motor; i.e. i_dCharacterizing a d-axis actual current of the motor; l is_dCharacterizing a d-axis inductance of the motor; l is_qCharacterizing a q-axis inductance of the electric machine.

In practical application, the given rotating speed of the motorAnd estimating the rotational speedPerforming Proportional Integral (PI) control to obtain a first PI operation result_p. Obtaining a first proportional integral operation result T_eAnd a first current W determined based on the phase of the input voltage_fIn the case of (3), the first proportional integral operation result T is subjected to_eAnd a first current W_fPerforming multiplication to obtain electricityGiven torque T of the machine_e. Wherein the content of the first and second substances,

here, K_PCharacterizing the proportional control coefficient, K_p＝Jω_asr/p；K_iThe integral control coefficient is characterized in that,j represents the rotational inertia of the motor; p represents the number of pole pairs of the motor; omega_asrCharacterizing the bandwidth of the current loop;and characterizing the damping coefficient of the motor. In practical applications, the bandwidth of the current loop is set to 20 hertz (Hz).

At a given torque T of the motor_eIn the case of (1), the formula is calculated based on the setting of the q-axis set current and the set torque T based on the motor_eDetermining the q-axis given current i of the motor_{q_ref}。

S202: and determining the d-axis given current of the motor based on the operating frequency of the motor, the output voltage amplitude of the inverter circuit and the maximum output voltage of the inverter circuit.

And determining the d-axis given current of the motor based on the integral operation result and the operation frequency of the motor. Wherein the output voltage amplitude of the inverter circuit isu_drefCharacterizing the last determined d-axis given voltage, u_qrefRepresenting the last determined q-axis given voltage; the maximum output voltage of the inverter circuit isu_dcIs the dc bus voltage of the motor.

It should be noted that, when the current is given to the d-axis of the motor in the k-th determination, u is_drefD-axis given voltage, u, determined for the k-1 th time_qrefThe voltage is given to the q-axis determined for the (k-1) th time.

In practical application, the d-axis given current i of the motor is determined based on the set calculation formula of the d-axis given current, the operating frequency of the motor, the output voltage amplitude of the inverter circuit and the maximum output voltage of the inverter circuit_{d_ref}. Wherein, the set calculation formula of the d-axis given current is as follows:

wherein, K_idCharacterizing the integral control coefficient, K_idDetermining based on the operating frequency of the motor;characterization pairPerforming integration;representing the amplitude of the output voltage of the inverter circuit; u shape_maxThe maximum output voltage of the inverter circuit is characterized,

it should be noted that the operating frequency of the motor generally refers to the mechanical frequency of the motor. Operating frequency and K of the electric machine_idAnd (4) positively correlating.

S203: and controlling the motor to operate based on the estimated angle of the motor, the q-axis given current, the d-axis given current, the q-axis actual current and the d-axis actual current.

Here, based on the q-axis given current and the q-axis actual current, it is determinedQ-axis set voltage u of motor_q(ii) a Determining d-axis given voltage u of the motor based on the d-axis given current and the d-axis actual current_d。

Determining the q-axis set voltage u of the motor_qAnd d-axis given voltage u_dBased on the estimated angle of the motorCarrying out Park inverse transformation on the determined q-axis given voltage and the determined d-axis given voltage to obtain alpha-axis voltage u_αAnd beta axis voltage u_β。

To obtain an alpha-axis voltage u_αAnd beta axis voltage u_βFor the case of (1), for the α -axis voltage u_αAnd beta axis voltage u_βPerforming Clark inverse transformation to obtain a three-phase voltage instruction; space Vector Modulation (SVM) is carried out on the basis of the three-phase voltage instruction and the direct-current bus voltage of the motor, so that a duty ratio control signal is determined, and a PWM signal is output to the inversion module on the basis of the duty ratio control signal to drive the motor to operate through the PWM signal.

Wherein, can pass through the formulaDetermining a d-axis set voltage u of an electric machine_d(ii) a By the formulaDetermining a q-axis setpoint voltage u of the electric machine_q。ψ_fIs the permanent magnet flux linkage of the motor.

In the scheme provided by the embodiment of the application, the d-axis given current i of the motor can be dynamically adjusted based on the running frequency of the motor_{d_ref}The flexibility of the weak magnetic current control is improved while the stable operation of the motor is ensured; due to the running frequency of the motor and K_idPositive correlation, therefore, when the operating frequency of the motor is low, the current i can be given by reducing the d-axis of the motor_{d_ref}The weak magnetic depth of the motor is reduced, so that the working current of the motor is reduced, the loss of the motor is reduced, and the motor is improvedThe efficiency of the motor is high.

As another embodiment of the present application, fig. 4 shows a schematic implementation flow chart of determining a d-axis given current of a motor in a field weakening control method provided by an embodiment of the present application. As shown in fig. 4, the determining a d-axis given current of the motor based on the operating frequency of the motor, the amplitude of the output voltage of the inverter circuit, and the maximum output voltage of the inverter circuit includes:

s401: an integral control coefficient is determined based on the operating frequency of the motor.

Comparing the operating frequency of the motor with a set frequency under the condition of acquiring the operating frequency of the motor to obtain a comparison result; determining an integral control coefficient K corresponding to the running frequency of the motor based on the comparison result_id. Wherein the integral control coefficient K_idAlso called the control coefficient of d-axis weak magnetic current.

In practical applications, the set frequency may be 50 Hz. It should be noted that, in some embodiments, the set frequency may be set based on the corresponding operating frequency of the motor when the motor operates at a low speed, and when the operating frequency of the motor is less than or equal to the set frequency, the motor operates at the low speed. By setting the set frequency, whether the motor is in a low-speed running state at present can be accurately identified based on the comparison result of the running frequency of the motor and the set frequency, and d-axis given current of the motor is reduced when the motor runs at a low speed, so that the flux weakening depth of the motor is reduced, and the efficiency of the motor is improved.

In some embodiments, to determine the integral control coefficient more accurately, the determining the integral control coefficient based on the operating frequency of the motor includes: and under the condition that the running frequency of the motor is less than or equal to the set frequency, determining that the integral control coefficient is zero. In practice, in f_rUnder the condition of less than or equal to 50Hz, K_id＝0；f_rCharacterizing the operating frequency of the motor. In some embodiments, to determine the integral control coefficient more accurately, the determining the integral control coefficient based on the operating frequency of the motor includes: when the running frequency of the motor is greater than the set frequencyIn the case of the rate, the integral control coefficient is determined based on the operating state of the motor.

Determining the current running state of the motor under the condition that the running frequency of the motor is greater than the set frequency; and determining an integral control coefficient based on the current running state of the motor. Wherein, the running state includes: stable operation, speed-up state or speed-down state. In practical application, when the operating frequency of the motor is greater than the set frequency, the higher the operating frequency of the motor is, the larger the determined integral control coefficient is, the deeper the flux weakening depth of the motor is, and the more stable the motor is.

When the running state of the motor is high speed, heavy load, speed increasing or speed decreasing, deeper weak magnetism is needed to ensure the stability of a motor system; when the running state of the motor is low-speed, light-load or stable running, the stability of the motor system can be ensured by shallow weak magnetism; in the scheme, under the condition that the running frequency of the motor is greater than the set frequency, an integral control coefficient is determined based on the current running state of the motor; when the running state of the motor is high speed, heavy load, speed increasing or speed reducing, the flux weakening depth of the motor is increased by increasing the given current of the d axis; when the running state of the motor is light load or stable running, the weak magnetic depth of the motor is reduced by reducing the given current of the d axis; therefore, the d-axis given current can be accurately adjusted according to different running states, and the precision of field weakening control can be improved.

In some embodiments, in order to determine the integral control coefficient more accurately, the determining the integral control coefficient based on the operating state of the motor in the case where the operating frequency of the motor is greater than a set frequency includes one of:

under the condition that the motor is in a first running state, determining the integral control coefficient based on a set function corresponding to the running frequency of the motor;

under the condition that the motor is in a second operation state, determining the integral control coefficient based on a set function corresponding to the operation frequency of the motor and based on a weak magnetic compensation value; wherein the content of the first and second substances,

the first running state represents that the motor runs stably; the second operating state characterizes the motor up-speed or down-speed.

In practical application, the corresponding set function of the running frequency of the motor is F (F)_r) At f_rGreater than 50Hz and the electric machine is in a first operating state, K_id＝F(f_r). Wherein, F (F)_r) Characterizing the independent variable as f_rFunction of F (F)_r) Satisfy f_rThe larger the value, the larger F (F)_r) The larger the value of (c).

At f_rGreater than 50Hz and the motor is in the second operating state, K_id＝F(f_r)+K₀. Wherein, K₀Characterizing the flux-weakening compensation value, K₀Is a positive number. During the process of increasing or decreasing the speed of the motor, the integral control coefficient is compensated through the weak magnetic compensation value, so that the motor can run more stably.

In addition, K is₀May be set to a positive number, K₀Or may be a dynamically adjusted positive number. When K is₀When a dynamically adjusted positive number, K can be determined based on the operating frequency of the motor₀. Wherein the operating frequency of the motor is equal to K₀Positive correlation, i.e. the greater the operating frequency of the motor, the determined K₀The larger.

Referring to FIG. 5, in practical application, at f_rThe integral control coefficient K is more than 50Hz and the motor is in the first running state_idGreater than 0 and less than or equal to 0.4; at f_rThe integral control coefficient K is more than 50Hz and the motor is in the second running state_idGreater than 0.16 and less than or equal to 0.56.

In FIG. 5, K is₀Equal to 0.16, in other embodiments, K₀Other positive numbers may be set.

S402: and determining q-axis given current of the motor based on the determined integral control coefficient, the output voltage amplitude of the inverter circuit and the maximum output voltage of the inverter circuit.

Here, in the case where the integral control coefficient is determined, the q-axis given current of the motor is determined based on the above equation (2).

In the scheme provided by the embodiment, the d-axis given current i used for calculating the motor can be dynamically adjusted based on the running frequency of the motor_{d_ref}Integral control coefficient K of_idAnd further determining d-axis given current i of the motor based on the determined integral control coefficient, the output voltage amplitude of the inverter circuit and the maximum output voltage of the inverter circuit_{d_ref}. Because the running frequency of the motor is used, the integral control coefficient K can be accurately determined_idAnd further improve the accuracy of the determined d-axis given current.

When the operating frequency of the motor is greater than the set frequency, the corresponding integral control coefficient is determined based on the operating state of the motor, so that the d-axis given current can be accurately adjusted according to different operating states, and the precision of flux weakening control can be improved.

In order to implement the method of the embodiment of the present application, an embodiment of the present application further provides a field weakening control device disposed on a motor driver or a household appliance including the motor driver and a motor, as shown in fig. 6, the field weakening control device includes:

a first determination unit 61 for determining a q-axis given current of the motor based on a phase of an input voltage, a given rotation speed of the motor, and an estimated rotation speed of the motor;

a second determining unit 62 for determining a d-axis given current of the motor based on an operation parameter of the compressor, an output voltage amplitude of the inverter circuit, and a maximum output voltage of the inverter circuit;

and a control unit 63 for controlling the operation of the motor based on the estimated angle of the motor, the q-axis given current, the d-axis given current, the q-axis actual current, and the d-axis actual current.

In some embodiments, the second determination unit 62 is configured to:

determining an integral control coefficient based on the operating frequency of the motor;

and determining q-axis given current of the motor based on the determined integral control coefficient, the output voltage amplitude of the inverter circuit and the maximum output voltage of the inverter circuit.

In some embodiments, the second determination unit 62 is configured to:

and under the condition that the running frequency of the motor is less than or equal to the set frequency, determining that the integral control coefficient is zero.

In some embodiments, the second determining unit 62 is configured to include:

and under the condition that the operating frequency of the motor is greater than a set frequency, determining the integral control coefficient based on the operating state of the motor.

In some embodiments, the second determination unit 62 is configured to perform one of:

under the condition that the motor is in a first running state, determining the integral control coefficient based on a set function corresponding to the running frequency of the motor;

under the condition that the motor is in a second operation state, determining the integral control coefficient based on a set function corresponding to the operation frequency of the motor and based on a weak magnetic compensation value; wherein the content of the first and second substances,

the first running state represents that the motor runs stably; the second operating state characterizes the motor up-speed or down-speed.

In some embodiments, the first determining unit 61 is configured to:

determining a given torque of the motor based on a phase of an input voltage, a given rotation speed of the motor, and an estimated rotation speed of the motor;

determining q-axis given current of the motor based on a set calculation formula of the q-axis given current and given torque of the motor; wherein the set calculation formula of the q-axis given current is as follows:

i_{q_ref}characterizing the q-axis given current; t is_eCharacterizing a given torque of the electric machine(ii) a p represents the number of pole pairs of the motor; k is a radical of_TCharacterizing a back electromotive force of the motor; i.e. i_dCharacterizing a d-axis actual current of the motor; l is_dCharacterizing a d-axis inductance of the motor; l is_qCharacterizing a q-axis inductance of the electric machine.

In practical applications, each unit included in the motor control device may be implemented by a processor in the motor control device. Of course, the processor needs to run the program stored in the memory to realize the functions of the above-described program modules.

It should be noted that: in the field weakening control device provided in the above embodiment, when the field weakening control is performed on the motor, only the division of the above program modules is taken as an example, and in practical applications, the processing distribution may be completed by different program modules according to needs, that is, the internal structure of the field weakening control device is divided into different program modules to complete all or part of the processing described above. In addition, the weak magnetic control device provided by the above embodiment and the weak magnetic control method embodiment belong to the same concept, and the specific implementation process thereof is detailed in the method embodiment and will not be described herein again.

Based on the hardware implementation of the program module, in order to implement the method of the embodiment of the present application, the embodiment of the present application further provides a home appliance. Fig. 7 is a schematic diagram of a hardware structure of a home appliance according to an embodiment of the present application, and as shown in fig. 7, the home appliance includes:

a communication interface 1 capable of information interaction with other devices such as a remote controller and the like;

and the processor 2 is connected with the communication interface 1 to realize information interaction with other equipment, and is used for executing the field weakening control method provided by one or more technical schemes when running a computer program. And the computer program is stored on the memory 3;

and a motor driver 4 for driving the motor 5.

In practice, of course, the various components in the household appliance are coupled together by means of the bus system 6. It will be appreciated that the bus system 6 is used to enable communications between these components. The bus system 6 comprises, in addition to a data bus, a power bus, a control bus and a status signal bus. But for the sake of clarity the various buses are labeled as bus system 6 in figure 7.

The memory 3 in the embodiment of the present application is used to store various types of data to support the operation of the home appliance. Examples of such data include: any computer program for operating on a household appliance.

It will be appreciated that the memory 3 may be either volatile memory or nonvolatile memory, and may include both volatile and nonvolatile memory. Among them, the nonvolatile Memory may be a Read Only Memory (ROM), a Programmable Read Only Memory (PROM), an Erasable Programmable Read-Only Memory (EPROM), an Electrically Erasable Programmable Read-Only Memory (EEPROM), a magnetic random access Memory (FRAM), a Flash Memory (Flash Memory), a magnetic surface Memory, an optical disk, or a Compact Disc Read-Only Memory (CD-ROM); the magnetic surface storage may be disk storage or tape storage. Volatile Memory can be Random Access Memory (RAM), which acts as external cache Memory. By way of illustration and not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Synchronous Static Random Access Memory (SSRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), Double Data Rate Synchronous Dynamic Random Access Memory (DDRSDRAM), Enhanced Synchronous Dynamic Random Access Memory (ESDRAM), Enhanced Synchronous Dynamic Random Access Memory (Enhanced Synchronous Dynamic Random Access Memory), Synchronous linked Dynamic Random Access Memory (DRAM, Synchronous Link Dynamic Random Access Memory), Direct Memory (DRmb Random Access Memory). The memory 3 described in the embodiments of the present application is intended to comprise, without being limited to, these and any other suitable types of memory.

The method disclosed in the above embodiment of the present application may be applied to the processor 2, or implemented by the processor 2. The processor 2 may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method may be performed by integrated logic circuits of hardware or instructions in the form of software in the processor 2. The processor 2 described above may be a general purpose processor, a DSP, or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, or the like. The processor 2 may implement or perform the methods, steps and logic blocks disclosed in the embodiments of the present application. A general purpose processor may be a microprocessor or any conventional processor or the like. The steps of the method disclosed in the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software modules may be located in a storage medium located in the memory 3, and the processor 2 reads the program in the memory 3 and in combination with its hardware performs the steps of the aforementioned method.

When the processor 2 executes the program, the process corresponding to the multi-core processor in each method according to the embodiment of the present application is implemented, and for brevity, details are not described here again.

In an exemplary embodiment, the present application further provides a storage medium, i.e. a computer storage medium, specifically a computer readable storage medium, for example, including a memory 3 storing a computer program, which can be executed by a processor 2 to complete the steps in the foregoing embodiments. The computer readable storage medium may be Memory such as FRAM, ROM, PROM, EPROM, EEPROM, Flash Memory, magnetic surface Memory, optical disk, or CD-ROM.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. The above-described device embodiments are merely illustrative, for example, the division of the unit is only a logical functional division, and there may be other division ways in actual implementation, such as: multiple units or components may be combined, or may be integrated into another system, or some features may be omitted, or not implemented. In addition, the coupling, direct coupling or communication connection between the components shown or discussed may be through some interfaces, and the indirect coupling or communication connection between the devices or units may be electrical, mechanical or other forms.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed on a plurality of network units; some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, all functional units in the embodiments of the present application may be integrated into one processing module, or each unit may be separately regarded as one unit, or two or more units may be integrated into one unit; the integrated unit can be realized in a form of hardware, or in a form of hardware plus a software functional unit.

Those of ordinary skill in the art will understand that: all or part of the steps for implementing the method embodiments may be implemented by hardware related to program instructions, and the program may be stored in a computer readable storage medium, and when executed, the program performs the steps including the method embodiments; and the aforementioned storage medium includes: a mobile storage device, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

The technical means described in the embodiments of the present application may be arbitrarily combined without conflict.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.