Method, device and system for controlling single-phase permanent magnet synchronous motor

Abstract

The invention provides a control method, device and system of a single-phase permanent magnet synchronous motor. The control method comprises the following steps of obtaining a target torque value according to a target rotating speed of the single-phase permanent magnet synchronous motor; acquiring a disturbance value of the single-phase permanent magnet synchronous motor, and compensating the target torque value according to the disturbance value to obtain a target current value; and obtaining a target voltage value according to the target current value, and driving the single-phase permanent magnet synchronous motor to operate according to the target voltage value. The method can ensure that the motor rapidly and accurately reaches the set rotating speed target, and is suitable for occasions with high requirements for dynamic performance and stability.

Description

Technical Field

[0001] The present invention relates to the field of motor control, and in particular to a control method, device and system for a single-phase permanent magnet synchronous motor. Background Art

[0002] Single-phase permanent magnet synchronous motors have the advantages of high efficiency, high power factor, small size, simple structure, and simple control circuit. Therefore, they are widely used in fields such as household appliances where performance requirements are not high.

[0003] In order to save costs, single-phase permanent magnet synchronous motor systems are generally not equipped with speed and position sensors, so the existing systems use speed open-loop control or position sensorless control. The existing closed-loop control method mainly generates a power device drive signal with a fixed relative position to the rotor through a specific modulation method based on the rotor position to ensure that the voltage input to the stator end of the motor is a sine wave or square wave. Due to the characteristics of the single-phase permanent magnet synchronous motor itself, when using the traditional sinusoidal wave control method, under the combined effect of back electromotive force, cogging torque, load torque, friction resistance torque and other factors, the motor torque pulsation is large, often reaching about 200%, resulting in poor steady-state speed response of the motor. At present, in the face of this problem, the control method of the single-phase permanent magnet synchronous motor lacks a systematic solution. Summary of the invention

[0004] The technical problem to be solved by the present disclosure is to overcome the defect in the prior art that the motor torque pulsation is large, resulting in poor steady-state speed response of the motor, and to provide a control method, device and system for a single-phase permanent magnet synchronous motor.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] The present invention provides a control method for a single-phase permanent magnet synchronous motor, the control method comprising the following steps:

[0007] Obtaining a target torque value according to a target speed of the single-phase permanent magnet synchronous motor;

[0008] Acquiring a disturbance value of the single-phase permanent magnet synchronous motor, and compensating the target torque value according to the disturbance value to obtain a target current value;

[0009] A target voltage value is obtained according to the target current value, and the single-phase permanent magnet synchronous motor is driven to operate according to the target voltage value.

[0010] In this scheme, the target torque value is first calculated according to the target speed, which provides a basis for the operation of the motor. Secondly, by obtaining the disturbance value of the motor, the target torque value is compensated, which effectively improves the adaptability and anti-interference ability of the motor when it is disturbed by the outside world. Then, the target current value is calculated according to the compensated target torque value, which provides a basis for the precise control of the motor. Next, the target voltage value is calculated according to the target current value, and the current value is converted into an actual voltage signal, so that the motor can perform corresponding actions according to the predetermined voltage signal. Finally, the single-phase permanent magnet synchronous motor is driven to operate according to the calculated target voltage value, realizing efficient and precise control of the motor. The entire control method has high control accuracy and stability.

[0011] Preferably, the obtaining of the disturbance value of the single-phase permanent magnet synchronous motor, and compensating the target torque value according to the disturbance value to obtain the target current value includes:

[0012] Using the disturbance value as a state variable, constructing a state space model of the single-phase permanent magnet synchronous motor;

[0013] outputting the target current value according to the state space model;

[0014] The disturbance value is at least one of back electromotive force disturbance, rotor friction, cogging torque, and load torque.

[0015] In this scheme, the state space model of the single-phase permanent magnet synchronous motor is constructed by taking the motor disturbance value as the state variable, and then the target current value is output according to the model, thereby realizing effective compensation and control of the motor disturbance. Specifically, this scheme considers several major disturbance factors that may be encountered during the operation of the motor, including back-EMF disturbance, rotor friction, cogging torque and load torque. These disturbance factors will affect the operating efficiency and stability of the motor. Through the state space model, these unpredictable disturbance factors can be incorporated into the control strategy, so that the motor controller can respond and adjust these disturbances in a timely manner. Through the state space model, the controller can not only monitor and identify the disturbances of the motor in real time, but also predict the impact of these disturbances on the performance of the motor, and adjust the control parameters of the motor, such as current size and phase, accordingly, to keep the motor running on the predetermined trajectory. The effectiveness of this control method lies in its ability to dynamically adapt to changes in the operation of the motor, improve the flexibility and robustness of the control, and thus ensure that the motor can maintain high performance and stable operation under different working conditions.

[0016] Preferably, obtaining a target voltage value according to the target current value includes:

[0017] Obtaining a real-time current value of the single-phase permanent magnet synchronous motor;

[0018] Calculating a difference between the target current value and the real-time current value;

[0019] The difference between the target current value and the real-time current value is output as the target voltage value through a current controller.

[0020] In this solution, first, the system monitors and obtains the actual current value of the single-phase permanent magnet synchronous motor. This is achieved through monitoring devices such as current sensors to ensure that the controller can obtain the most accurate real-time data. Next, the system calculates the difference between the target current value and the real-time current value. This difference represents the deviation between the current operating state of the motor and the target state, and is the basis for the controller to adjust. Finally, this difference will be processed by the current controller and the corresponding target voltage value will be output. It adjusts the input voltage of the motor according to the difference to reduce or eliminate this difference, so that the real-time current value is close to the target current value. The single-phase permanent magnet synchronous motor can respond quickly and adjust to the set target current, thereby achieving precise speed and torque control. This control method improves the dynamic performance and steady-state performance of the motor, ensuring that the motor can maintain high efficiency and stable performance under various operating conditions.

[0021] Preferably, the driving the single-phase permanent magnet synchronous motor to operate according to the target voltage value includes:

[0022] Performing pulse width modulation on the target voltage value to obtain a driving signal;

[0023] The driving signal is output to the single-phase inverter, and the single-phase permanent magnet synchronous motor is driven to operate by the single-phase inverter.

[0024] In this solution, the target voltage value processed by pulse width modulation is converted into drive signals, which are the key to controlling the operation of the motor. The drive signal usually contains multiple pulses, each pulse corresponds to a different duty cycle of a phase in the motor, so that the current of each phase can be controlled, thereby controlling the speed and torque of the motor. The drive signal is output to a single-phase inverter. An inverter is an electronic device that can convert direct current into alternating current. In this application, the inverter converts the drive signal into an alternating current signal, which is then applied to the stator of a single-phase permanent magnet synchronous motor to drive the motor to operate.

[0025] Preferably, the current controller is one or more of a PI controller, a PR controller, a repetitive controller and a hysteresis controller.

[0026] Preferably, obtaining the target torque value according to the target speed of the single-phase permanent magnet synchronous motor includes:

[0027] Obtaining a difference between a target speed and an actual speed of the single-phase permanent magnet synchronous motor;

[0028] The target torque value is obtained according to the difference between the target speed and the actual speed of the single-phase permanent magnet synchronous motor.

[0029] In this solution, the system monitors and obtains the actual speed of the single-phase permanent magnet synchronous motor. This is achieved through monitoring equipment such as speed sensors, ensuring that the controller can obtain the most accurate real-time speed data. The difference between the target speed and the actual speed is calculated. This difference represents the deviation between the current operating state of the motor and the target state. The controller calculates the target torque value based on this deviation, that is, the torque required to make the motor reach the target speed.

[0030] Another aspect of the present invention provides a control device for a single-phase permanent magnet synchronous motor, the control device comprising:

[0031] A speed controller, used to obtain a target torque value according to a target speed;

[0032] A motor disturbance compensation module, used for obtaining a disturbance value of the single-phase permanent magnet synchronous motor, compensating the target torque value according to the disturbance value, and obtaining a target current value;

[0033] The motor control module is used to obtain a target voltage value according to the target current value, and drive the single-phase permanent magnet synchronous motor to operate according to the target voltage value.

[0034] Preferably, the motor disturbance compensation module comprises:

[0035] A motor state observation submodule, used to obtain the actual rotation speed of the single-phase permanent magnet synchronous motor and the disturbance value of the single-phase permanent magnet synchronous motor;

[0036] The disturbance compensation submodule is used to compensate the target torque value according to the disturbance value to obtain a target current value.

[0037] Preferably, the speed controller is used to obtain the target torque value according to the difference between the target speed and the actual speed of the single-phase permanent magnet synchronous motor.

[0038] Preferably, the motor control module comprises:

[0039] A phase current sampling submodule, used to obtain the real-time current value of the single-phase permanent magnet synchronous motor;

[0040] a current controller, configured to output the difference between the target current value and the real-time current value as the target voltage value;

[0041] A pulse width modulator, used for performing pulse width modulation on the target voltage value to obtain a driving signal;

[0042] The single-phase inverter is used to drive the single-phase permanent magnet synchronous motor to operate according to the driving signal.

[0043] On the other hand, the present invention provides a single-phase permanent magnet synchronous motor system, including a single-phase permanent magnet synchronous motor and a control device for the single-phase permanent magnet synchronous motor as described above, wherein the single-phase permanent magnet synchronous motor system implements the control method for the single-phase permanent magnet synchronous motor as described above.

[0044] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present disclosure.

[0045] The positive and progressive effects of the present disclosure are: first, the target torque value is calculated according to the target speed, which provides a basis for the operation of the motor. Secondly, by obtaining the disturbance value of the motor, the target torque value is compensated, which effectively improves the adaptability and anti-interference ability of the motor when it is disturbed by the outside world. Then, the target current value is calculated according to the compensated target torque value, which provides a basis for the precise control of the motor. By real-time monitoring and compensation of these disturbances, their influence on the motor speed response can be reduced, and the stability and response speed of the motor can be improved. Next, the target voltage value is calculated according to the target current value, and the current value is converted into an actual voltage signal, so that the motor can perform corresponding actions according to the predetermined voltage signal. Finally, the single-phase permanent magnet synchronous motor is driven to operate according to the calculated target voltage value, thereby realizing efficient and precise control of the motor. It can ensure that the motor can quickly and accurately reach the set speed target, and is suitable for occasions with high requirements for dynamic performance and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a flow chart of a control method for a single-phase permanent magnet synchronous motor provided in Example 1 of the present invention.

[0047] Figure 2 This is a connection block diagram of a control device for a single-phase permanent magnet synchronous motor provided in Example 2 of the present invention.

[0048] Figure 3 This is a main circuit diagram of a single-phase permanent magnet synchronous motor drive provided in Example 2 of the present invention.

[0049] Figure 4 This is a back electromotive force waveform diagram provided in Example 2 of the present invention.

[0050] Figure 5 This is a cogging torque waveform diagram provided for Example 2 of the present invention.

[0051] Figure 6 This is a diagram of actual current after disturbance compensation provided in Example 2 of the present invention.

[0052] Figure 7This is a speed diagram of the motor during steady-state operation provided by Example 2 of the present invention.

[0053] Figure 8 This is a total torque diagram of the motor during steady-state operation provided by Embodiment 2 of the present invention. DETAILED DESCRIPTION

[0054] The present disclosure is further described below by way of examples, but the present disclosure is not limited to the scope of the examples.

[0055] Prefixes such as "first" and "second" are used in the embodiments of the present disclosure only to distinguish different description objects, and have no limiting effect on the position, order, priority, quantity or content of the described objects. The use of prefixes such as ordinal numbers to distinguish description objects in the embodiments of the present disclosure does not constitute a limitation on the described objects. For the statement of the described objects, please refer to the description in the context of the claims or embodiments, and no unnecessary limitation should be constituted due to the use of such prefixes. In addition, in the description of the present embodiment, unless otherwise specified, the meaning of "plurality" is two or more.

[0056] In the embodiments of the present disclosure, the collection, storage, use, processing, transmission, provision and disclosure of user personal information involved are in compliance with the provisions of relevant laws and regulations and do not violate public order and good morals.

[0057] Example 1

[0058] Generally, the poor steady-state speed response of a single-phase permanent magnet synchronous motor means that after the motor is subjected to external disturbances or control system instructions, the speed of the motor reaches a stable state slowly, or there is a large error between the speed and the expected value when the stable state is reached. This situation usually indicates that the dynamic performance of the motor is poor, the response time is long, the anti-interference ability is weak, or the control strategy is not effective enough. The embodiment of the present application provides a control method for a single-phase permanent magnet synchronous motor, which aims to improve the stability and response speed of the motor.

[0059] Figure 1 This is a flow chart of a control method for a single-phase permanent magnet synchronous motor provided in this embodiment. The control method is used to control the single-phase permanent magnet synchronous motor. The control method includes the following steps:

[0060] S101, obtaining a target torque value according to a target speed of the single-phase permanent magnet synchronous motor;

[0061] Specifically, the difference between the target speed and the actual speed of the single-phase permanent magnet synchronous motor is obtained; the target torque value is obtained according to the difference between the target speed and the actual speed of the single-phase permanent magnet synchronous motor. In this embodiment, this step is to determine the torque that the motor needs to increase or decrease by comparing the given speed and the current speed of the motor in order to reach the target speed. The given speed of the motor is subtracted from the observed speed obtained by the motor state observer, and the result is output as the torque given value T of the motor through the speed regulator. * , that is, given the motor mechanical angular velocity ω r * and the estimated mechanical angular velocity ω r The result is passed through the speed PI controller and the output is the motor torque setting value (target value) T e * ,

[0062] The expression is T e * =K p (ω r * -ω r )+K i ∫(ω r * -ω r ). p is the proportional gain, K i is the integral gain. It should be noted that in practical applications, K p and K i The value of usually needs to be determined through experimentation and adjustment to achieve precise control of the system output.

[0063] S102, obtaining a disturbance value of the single-phase permanent magnet synchronous motor, compensating the target torque value according to the disturbance value, and obtaining a target current value;

[0064] The motor disturbance value is used as the state variable to construct the state space model of the single-phase permanent magnet synchronous motor; the target current value is output according to the state space model; wherein the motor disturbance value is at least one of back electromotive force disturbance, rotor friction, cogging torque, and load torque. In this embodiment, in order to accurately describe the dynamic behavior of the motor, the state space model is used to model the motor. The state space model can clearly represent the dynamic relationship of the motor, including the motor's voltage, current, torque, speed and other physical quantities. Obtain the disturbance values ​​during motor operation, which include:

[0065] Back EMF disturbance (generated by the motor's own electromagnetic field. Back EMF is the electromotive force generated by electromagnetic induction when the motor rotates, and its direction is opposite to the power supply voltage applied to the motor. In a DC motor, the magnitude of the back EMF is proportional to the motor's speed. When the motor load changes suddenly or the motor accelerates, the back EMF will change rapidly. If this change cannot be compensated by the motor controller in time, it will cause fluctuations in the motor speed. This is the back EMF disturbance.

[0066] Rotor friction: Rotor friction includes static and dynamic friction between the motor rotor and stator. These friction forces will change with the motor speed and load, resulting in unstable motor speed and energy loss. In precision motion control applications, the impact of friction disturbances is particularly significant.

[0067] Cogging torque: Cogging torque is a nonlinear torque that is generated by the interaction between the magnetic flux generated in the motor windings and the teeth on the rotor. When the rotor teeth are aligned with the stator slots, the flux path is minimized and the torque generated is maximized; when the teeth and slots are not aligned, the flux path increases and the torque decreases. This periodic torque fluctuation is the cogging torque disturbance, which causes vibration and noise when the motor is running.

[0068] Load torque: It is the torque applied to the motor shaft by the mechanical load driven by the motor (such as pumps, fans, robotic arms, etc.). When the load demand changes, the load torque will also change. If this change cannot be adjusted in time by the motor control system, it will cause the motor speed to fluctuate and affect the stable operation of the motor.

[0069] The above disturbance values ​​are used as state variables to construct the state space model of the motor. The influence of the above disturbances on the motor torque is predicted and compensated according to the model, so as to obtain a disturbance-free target current value. Specifically, the disturbances such as back EMF disturbance, rotor friction, cogging torque, load torque, etc. are observed, and the disturbance compensation is calculated based on the torque given by T. * (target torque value), get the motor phase current given i * , which is the target current value. The principles of motor state observation and disturbance compensation are as follows:

[0070] With phase current i and rotor mechanical angular velocity ω r 、Rotor electrical angle θ e The state space model of a single-phase permanent magnet synchronous motor with is the state variable:

[0071]

[0072] Where: R is the motor phase resistance, L is the motor phase inductance, k e is the motor back EMF constant, u is the motor terminal voltage, J is the moment of inertia, B is the rotor friction coefficient, T cis the cogging torque, T l is the load torque, and P is the number of pole pairs. In actual operation, it is difficult to obtain accurate parameters for B, T c and T l The value of cannot be obtained online, so the last three terms of the second equation of equation (1.1) are combined into a total disturbance torque effect T d / J, this disturbance torque can be considered unchanged in a control cycle and expanded into a state variable:

[0073]

[0074] For the system (1.2), take the current i as the output variable and design the observer:

[0075]

[0076] The four control laws are:

[0077]

[0078] Finally, the observed internal disturbance (back electromotive force disturbance) and external disturbance (the sum of friction, cogging torque, and load torque disturbance) are compensated to the output of the torque regulator to obtain the current set value.

[0079] S103. Obtain a target voltage value according to the target current value, and drive the single-phase permanent magnet synchronous motor to operate according to the target voltage value.

[0080] Obtain the real-time current value of the single-phase permanent magnet synchronous motor; calculate the difference between the target current value and the real-time current value; output the difference between the target current value and the real-time current value as a target voltage value through a current controller. Perform pulse width modulation on the target voltage value to obtain a drive signal; output the drive signal to the single-phase inverter, and drive the single-phase permanent magnet synchronous motor to operate through the single-phase inverter. The current controller is one or more of a PI controller, a PR controller, a repetitive controller, and a hysteresis controller. In this embodiment, the motor current is sampled in the drive circuit to obtain the feedback value of the current at each moment, and the current set value is subtracted from the feedback value. The result is passed through the current controller and output as a motor voltage reference value u *. Based on the undisturbed target current value and the real-time current value of the motor, the difference between the two is calculated. This difference will be used as the input of the current controller. The controller is responsible for adjusting the input voltage of the motor to reduce the difference between the actual current and the target current. The difference output by the current controller will be used to generate the target voltage value. This target voltage value is generated by pulse width modulation (PWM) technology. PWM technology can convert continuous analog signals into switching signals. The width of the pulse varies according to the target voltage. The wider the pulse width, the higher the average voltage applied to the motor winding. Then it is converted into an AC signal that can be recognized by the motor through a single-phase inverter. The inverter consists of a series of switching devices (such as transistors, IGBTs, etc.). The switching devices switch quickly according to the pulses of the PWM signal, thereby generating a modulated AC voltage on the motor winding. Finally, the motor is driven by the single-phase inverter to run. The motor will generate corresponding torque according to the received voltage signal. The modulated AC voltage causes the current in the motor winding to change, generating a rotating magnetic field, thereby driving the motor rotor to rotate to achieve the predetermined target speed. The rotation speed and torque of the motor rotor are related to the frequency, amplitude and phase of the applied voltage and current.

[0081] In this embodiment, the current controller includes but is not limited to:

[0082] 1) PI controller has good tracking effect for most types of current signals;

[0083] 2) PR controller, used to track the sinusoidal current reference without static error;

[0084] 3) Repetitive controllers for tracking other periodic current signals without static errors;

[0085] 4) Hysteresis controller;

[0086] 5) Other controllers and combinations of the above controllers.

[0087] In specific applications, the motor can be selected and optimized according to its specific operating status and performance requirements.

[0088] The control method of this embodiment can be applied to refrigerators, air conditioners, fans and other occasions where single-phase permanent magnet synchronous motors are used. By using this method, closed-loop control of the speed of a single-phase permanent magnet synchronous motor can be achieved without installing a position sensor; the adverse effects of the cogging torque, uncertainty of the rotor friction coefficient, load torque, and the back electromotive force characteristics of the motor itself on the motor can be eliminated, the torque pulsation of the single-phase permanent magnet synchronous motor can be weakened, and the stable operation of the motor can be achieved.

[0089] Example 2

[0090] This embodiment provides a single-phase permanent magnet synchronous motor system, including a single-phase permanent magnet synchronous motor and a control device for the single-phase permanent magnet synchronous motor. The single-phase permanent magnet synchronous motor system implements the control method steps of the single-phase permanent magnet synchronous motor as described in Example 1.

[0091] Among them, the control device of the single-phase permanent magnet synchronous motor is as follows Figure 2 As shown, it shows a schematic diagram of module connection of a control device for a single-phase permanent magnet synchronous motor of this embodiment, the device comprising:

[0092] A speed controller 1, used for obtaining a target torque value according to a target speed;

[0093] The motor disturbance compensation module 2 is used to obtain the disturbance value of the single-phase permanent magnet synchronous motor, and compensate the target torque value according to the disturbance value to obtain the target current value. The disturbance value is at least one of back electromotive force disturbance, rotor friction, cogging torque, and load torque.

[0094] The motor disturbance compensation module 2 includes: a motor state observation submodule, which is used to obtain the actual speed of the single-phase permanent magnet synchronous motor and the disturbance value of the motor; a disturbance compensation submodule, which is used to compensate the target torque value according to the disturbance value to obtain the target current value. The speed controller 1 is used to obtain the target torque value according to the difference between the target speed and the actual speed of the single-phase permanent magnet synchronous motor.

[0095] The motor control module is used to obtain the target voltage value according to the target current value, and drive the single-phase permanent magnet synchronous motor to operate according to the target voltage value. The motor control module specifically includes: a phase current sampling submodule 4, which is used to obtain the real-time current value of the single-phase permanent magnet synchronous motor; a current controller 3, which is used to output the difference between the target current value and the real-time current value as a target voltage value; a pulse width modulator 5, which is used to perform pulse width modulation on the target voltage value to obtain a drive signal; a single-phase inverter 6, which is used to drive the single-phase permanent magnet synchronous motor to operate according to the drive signal.

[0096] Combine the following Figure 2 and 3 Further explanation: The device of this embodiment obtains the target speed (given speed ω) when it is running. r * ), the actual speed ω is obtained by the motor state observation module r , the given speed ω r * With the actual speed ω r The result is passed through the speed controller 1 and output as the target torque value of the motor (i.e. the torque given value T *The speed controller 1 is a PI regulator. The given value is transmitted back to the motor disturbance compensation module 2, and the motor disturbance compensation module 2 obtains the disturbance value of the single-phase permanent magnet synchronous motor, and compensates the target torque value according to the motor disturbance value to obtain the target current value i * The specific compensation algorithm is as described in Example 1. The phase current sampling submodule 4 samples the real-time current of the single-phase permanent magnet synchronous motor, obtains the real-time phase current i of the motor through A / D conversion and phase current reconstruction; * The result is input into the current controller 3 and the output is the target voltage value u of the motor. * The current controller is a current PI regulator. Finally, the pulse width modulator 5 performs pulse width modulation on the target voltage value to obtain a drive signal. The single-phase inverter 6 is connected to U d , U d It is the DC bus voltage, which supplies power to the drive system and is generated by a DC power supply or an AC input rectifier circuit. The drive signal is output to the single-phase inverter 6 to drive the single-phase permanent magnet synchronous motor to operate. It should be noted that the i received by the motor disturbance compensation module 2 is the same signal as the i output by the phase current sampling submodule 4, and the voltage value u* received by the motor disturbance compensation module 2 is the target voltage value u* output by the current controller 3 delayed by one control cycle.

[0097] This embodiment achieves high-precision control of a single-phase permanent magnet synchronous motor through the coordinated work of components such as a speed controller, a motor disturbance compensation module, and a motor control module, thereby improving the operating efficiency and stability of the motor. It also has strong applicability and can meet the high requirements of modern industry for motor control performance. In the actual operation process, it can quickly respond to various disturbances in the operation of the motor, such as load changes, temperature fluctuations, etc., and ensure that the motor output is always kept in the best state by compensating the disturbance value in real time, which greatly improves the reliability and robustness of the motor.

[0098] The control device of this embodiment is described below by a specific example: Figure 3 It is a single-phase permanent magnet synchronous motor drive main circuit diagram, where U d It is the DC bus voltage, which supplies power to the drive system and is generated by a DC power supply or an AC input rectifier circuit. dc is the bus capacitor, which is used to stabilize the bus voltage, R sam is the sampling resistor, which provides the phase current information of the motor during operation to the control system; S A , S B , S A '、S B' are four power devices and diodes connected in anti-parallel at both ends of the power devices. The four power devices form two bridge arms. M is a single-phase permanent magnet synchronous motor. Both ends of the single-phase winding are connected to the two bridge arms. The switching signal generated by the control algorithm is added to the gate (gate) of the power device to control the power device to turn on / off, thereby realizing the control of the motor.

[0099] The method described in Example 1 is usually written as a program in the MCU in the control circuit. The current sampling and processing circuit converts the current value sampled by the sampling resistor into a digital signal and gives it to the control circuit. The function of the drive circuit is to convert the PWM pulse generated by the control circuit (i.e. Figure 3 The four-way signal generated by the pulse width modulation in the middle is converted into a switching signal that can drive the four power devices SA, SB, SA', and SB'. The single-phase inverter 6 corresponds to Figure 3 The four power devices in ( Figure 2 The drive circuit is omitted), the phase current sampling submodule 4 corresponds to Figure 3 Sampling resistor + current sampling and processing circuit.

[0100] The target motor mechanical angular velocity ω r * The mechanical angular velocity ω obtained in real time r The result is passed through the speed PI regulator and the output is the target torque value T of the motor. e * , the expression is T e * =K p (ω r * -ω r )+K i ∫(ω r * -ω r ).

[0101] Taking a single-phase permanent magnet synchronous motor with a two-pole stator resistance of 45.6Ω, a stator inductance of 1.117H, a rated speed of 1500rpm, and a rated torque of 0.17Nm as an example, its back EMF waveform and cogging torque waveform are as follows: Figure 4 and Figure 5 As shown, in order to achieve the effect of reducing torque ripple, the actual current after observing and compensating the disturbance is as follows Figure 6 shown.

[0102] pass Figure 3 The sampling resistor in the motor samples the phase current of the motor, and obtains the real-time phase current i of the motor through A / D conversion and phase current reconstruction. * The result is input into the current PI regulator and the output is the target voltage value u of the motor. *,

[0103] The expression is u * =K p (i * -i)+K i ∫(i * -i).

[0104] The target voltage value is output as a driving signal of a single-phase inverter after pulse width modulation, and the motor is driven by the single-phase inverter. The speed and total torque of the motor in steady-state operation are respectively as follows: Figure 7 and Figure 8 As shown, it can be seen that the motor torque pulsation is small and the speed is relatively stable.

[0105] For the device embodiment, since its basic implementation method corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The device embodiment described above is only illustrative, in which the units or modules described as separate components may or may not be physically separated, and the components as units or modules may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the disclosed solution.

[0106] Although the specific embodiments of the present disclosure are described above, those skilled in the art should understand that this is only an example, and the protection scope of the present disclosure is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present disclosure, but these changes and modifications all fall within the protection scope of the present disclosure.

Claims

1. A control method for a single-phase permanent magnet synchronous motor, characterized in that: The control method comprises the following steps: Obtaining a target torque value according to a target speed of the single-phase permanent magnet synchronous motor; Acquiring a disturbance value of the single-phase permanent magnet synchronous motor, and compensating the target torque value according to the disturbance value to obtain a target current value; A target voltage value is obtained according to the target current value, and the single-phase permanent magnet synchronous motor is driven to operate according to the target voltage value.

2. The control method according to claim 1, characterized in that: The obtaining of the disturbance value of the single-phase permanent magnet synchronous motor, and compensating the target torque value according to the disturbance value to obtain the target current value, includes: Using the disturbance value as a state variable, constructing a state space model of the single-phase permanent magnet synchronous motor; outputting the target current value according to the state space model; The disturbance value is at least one of back electromotive force disturbance, rotor friction, cogging torque, and load torque.

3. The control method according to claim 1, characterized in that: Obtaining a target voltage value according to the target current value includes: Obtaining a real-time current value of the single-phase permanent magnet synchronous motor; Calculating a difference between the target current value and the real-time current value; The difference between the target current value and the real-time current value is output as the target voltage value through a current controller.

4. The control method according to claim 3, characterized in that: The step of driving the single-phase permanent magnet synchronous motor to operate according to the target voltage value includes: Performing pulse width modulation on the target voltage value to obtain a driving signal; The driving signal is output to the single-phase inverter, and the single-phase permanent magnet synchronous motor is driven to operate by the single-phase inverter.

5. The control method according to claim 3, characterized in that: The current controller is one or more of a PI controller, a PR controller, a repetitive controller and a hysteresis controller.

6. The control method according to claim 1, characterized in that: The obtaining of the target torque value according to the target speed of the single-phase permanent magnet synchronous motor comprises: Obtaining a difference between a target speed and an actual speed of the single-phase permanent magnet synchronous motor; The target torque value is obtained according to the difference between the target speed and the actual speed of the single-phase permanent magnet synchronous motor.

7. A control device for a single-phase permanent magnet synchronous motor, characterized in that: The control device comprises: A speed controller, used to obtain a target torque value according to a target speed; A motor disturbance compensation module, used for obtaining a disturbance value of the single-phase permanent magnet synchronous motor, compensating the target torque value according to the disturbance value, and obtaining a target current value; The motor control module is used to obtain a target voltage value according to the target current value, and drive the single-phase permanent magnet synchronous motor to operate according to the target voltage value.

8. The control device according to claim 7, characterized in that The motor disturbance compensation module comprises: A motor state observation submodule, used to obtain the actual rotation speed of the single-phase permanent magnet synchronous motor and the disturbance value of the single-phase permanent magnet synchronous motor; A disturbance compensation submodule, used for compensating the target torque value according to the disturbance value to obtain a target current value; The speed controller is used to obtain the target torque value according to the difference between the target speed and the actual speed of the single-phase permanent magnet synchronous motor.

9. The control device according to claim 8, characterized in that The motor control module comprises: A phase current sampling submodule, used to obtain the real-time current value of the single-phase permanent magnet synchronous motor; A current controller, configured to output a difference between a target current value and the real-time current value as the target voltage value; A pulse width modulator, used for performing pulse width modulation on the target voltage value to obtain a driving signal; The single-phase inverter is used to drive the single-phase permanent magnet synchronous motor to operate according to the driving signal.

10. A single-phase permanent magnet synchronous motor system, characterized in that: It comprises a single-phase permanent magnet synchronous motor and a control device for the single-phase permanent magnet synchronous motor as described in any one of claims 7 to 9, and the single-phase permanent magnet synchronous motor system implements the control method steps of the single-phase permanent magnet synchronous motor as described in any one of claims 1 to 6.

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