Control method, system and device of permanent magnet synchronous motor

Abstract

The application provides a control method, system and device of a permanent magnet synchronous motor, and belongs to the technical field of motor control. In the method, a motor speed coefficient is introduced in the adjustment process of a PI regulator to obtain a current adjustment value. Since different motor speed coefficients correspond to different motor speed value intervals, the current adjustment value obtained by the above method is associated with the real-time motor speed value, so that in the case that the real-time motor speed value is located in each motor speed value interval, a reasonable current adjustment value can be obtained based on the motor speed coefficient corresponding to the motor speed value interval. Through the above method, in the case that the real-time motor speed value changes at a high speed, the current in the permanent magnet synchronous motor can also be quickly and stably adjusted through the current adjustment value, thereby guaranteeing the safe and high-speed operation of the permanent magnet synchronous motor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor control, and particularly relates to a control method, system and device of a permanent magnet synchronous motor. BACKGROUND

[0002] In the working process of the permanent magnet synchronous motor, as the motor speed gradually increases, the back electromotive force of the permanent magnet synchronous motor also linearly increases. When the motor speed exceeds the base speed, the back electromotive force will approach or exceed the maximum input voltage of the permanent magnet synchronous motor, which will inhibit the current flow in the permanent magnet synchronous motor, thereby causing the permanent magnet synchronous motor to be unable to continue to accelerate or stably operate. Usually, the voltage condition of the permanent magnet synchronous motor is detected in real time, and when the back electromotive force approaches the maximum input voltage, the field weakening current is obtained through a PI regulator, so as to reduce the direct-axis current, weaken the air gap magnetic field, and reduce the back electromotive force, thereby increasing the motor speed under the condition of maintaining voltage balance. However, in the case of high-speed change of the motor speed, the direct-axis current cannot be quickly and stably adjusted through the PI regulator, and therefore the safe and high-speed operation of the permanent magnet synchronous motor cannot be ensured. SUMMARY

[0003] The embodiments of the present application provide a control method, system and device of a permanent magnet synchronous motor. In the method, a motor speed coefficient is introduced in the adjustment process of a PI regulator. Since the current adjustment value is associated with the motor speed value, in the case of high-speed change of the motor speed value, the current in the permanent magnet synchronous motor can also be quickly and stably adjusted through the current adjustment value, thereby ensuring the safe and high-speed operation of the permanent magnet synchronous motor. The technical solution is as follows:

[0004] In one aspect, a control method of a permanent magnet synchronous motor is provided, and the method comprises:

[0005] inputting a product value of a voltage utilization rate difference value and a motor speed coefficient into a PI regulator to obtain a current adjustment value, the voltage utilization rate difference value being a difference value between an actual voltage utilization rate and a reference voltage utilization rate, different motor speed coefficients corresponding to different motor speed value intervals;

[0006] in a case where a motor speed value of the permanent magnet synchronous motor is greater than a first preset speed value, driving the permanent magnet synchronous motor to operate based on the current adjustment value and a reference current value;

[0007] in a case where the motor speed value is not greater than the first preset speed value, driving the permanent magnet synchronous motor to operate based on the reference current value.

[0008] In some embodiments, the inputting of the product value of the voltage utilization rate difference value and the motor speed coefficient into the PI regulator to obtain the current adjustment value comprises:

[0009] In the case where the motor speed value is not greater than a second preset speed value, a product value of the voltage utilization difference and a first motor speed coefficient is input into a PI regulator to obtain a current adjustment value;

[0010] In the case where the motor speed value is greater than the second preset speed value, a product value of the voltage utilization difference and a second motor speed coefficient is input into a PI regulator to obtain a current adjustment value, the second motor speed coefficient being less than the first motor speed coefficient.

[0011] In some embodiments, the method further comprises:

[0012] Based on the motor speed value, an intermediate coefficient is determined through a first preset table, the first preset table being used to record a plurality of motor speed values and an intermediate coefficient corresponding to each motor speed value, the intermediate coefficient being less than 1;

[0013] The motor speed value and the intermediate coefficient are multiplied to obtain the second motor speed coefficient.

[0014] In some embodiments, the method further comprises:

[0015] The first intermediate value and the second intermediate value are compared to obtain the actual voltage utilization, the first intermediate value being used to represent an output voltage value of a motor controller, and the second intermediate value being used to represent an input voltage value of the motor controller.

[0016] In some embodiments, the method further comprises:

[0017] Based on a motor torque value, a reference current value is determined through a second preset table, the second preset table being used to record a plurality of motor torque values and a reference current value corresponding to each motor torque value.

[0018] In some embodiments, the reference current value comprises a reference direct-axis current value and a reference quadrature-axis current value;

[0019] In the case where the motor speed value of the permanent magnet synchronous motor is greater than a first preset speed value, based on the current adjustment value and the reference current value, the permanent magnet synchronous motor is driven to operate, comprising:

[0020] In the case where the motor speed value of the permanent magnet synchronous motor is greater than a first preset speed value, the reference direct-axis current value and the current adjustment value are added to obtain a target direct-axis current value;

[0021] Based on a motor torque value and the target direct-axis current value, a target quadrature-axis current value is determined;

[0022] drive the permanent magnet synchronous motor to operate based on the target direct-axis current value and the target quadrature-axis current value in a case where the target direct-axis current value and the target quadrature-axis current value meet a preset condition.

[0023] In some embodiments, the reference current value includes a reference direct-axis current value and a reference quadrature-axis current value.

[0024] The driving the permanent magnet synchronous motor to operate based on the reference current value in a case where the motor speed value is not greater than the first preset speed value includes:

[0025] In a case where the motor speed value is not greater than the first preset speed value, determining the reference direct-axis current value as a target direct-axis current value and determining the reference quadrature-axis current value as a target quadrature-axis current value.

[0026] drive the permanent magnet synchronous motor to operate based on the target direct-axis current value and the target quadrature-axis current value in a case where the target direct-axis current value and the target quadrature-axis current value meet a preset condition.

[0027] In some embodiments, the driving the permanent magnet synchronous motor to operate based on the target direct-axis current value and the target quadrature-axis current value in a case where the target direct-axis current value and the target quadrature-axis current value meet a preset condition includes:

[0028] determining a square root value of a sum of squares of the target direct-axis current value and the target quadrature-axis current value as a synthetic current value;

[0029] drive the permanent magnet synchronous motor to operate based on the target direct-axis current value and the target quadrature-axis current value in a case where the synthetic current value is not greater than a running current threshold.

[0030] In some embodiments, the method further includes:

[0031] In a case where the synthetic current value is greater than the running current threshold, determining a square root value of a square difference between the running current threshold and the target direct-axis current value as an updated target quadrature-axis current value, the updated target quadrature-axis current value being less than the target quadrature-axis current value;

[0032] drive the permanent magnet synchronous motor to operate based on the target direct-axis current value and the updated target quadrature-axis current value.

[0033] In another aspect, a control system of a permanent magnet synchronous motor is provided, the control system including a motor calibration bench, a motor controller, and a permanent magnet synchronous motor.

[0034] The motor calibration bench is configured to simulate an operating environment of the permanent magnet synchronous motor.

[0035] The motor controller is configured to control a parameter value of an operating parameter of the permanent magnet synchronous motor, the operating parameter including a motor torque value and a motor speed value.

[0036] The permanent magnet synchronous motor is configured to operate under the control of the motor controller.

[0037] In another aspect, a control device of a permanent magnet synchronous motor is provided, the device comprising:

[0038] The adjusting module is configured to input a product value of a voltage utilization difference and a motor speed coefficient into a PI regulator to obtain a current adjustment value, the voltage utilization difference being a difference between an actual voltage utilization and a reference voltage utilization, different motor speed coefficients corresponding to different motor speed value intervals.

[0039] The driving module is configured to drive the permanent magnet synchronous motor to operate based on the current adjustment value and a reference current value when a motor speed value of the permanent magnet synchronous motor is greater than a first preset speed value.

[0040] The driving module is further configured to drive the permanent magnet synchronous motor to operate based on the reference current value when the motor speed value is not greater than the first preset speed value.

[0041] In some embodiments, the adjusting module is configured to input a product value of the voltage utilization difference and a first motor speed coefficient into the PI regulator to obtain the current adjustment value when the motor speed value is not greater than a second preset speed value, and input a product value of the voltage utilization difference and a second motor speed coefficient into the PI regulator to obtain the current adjustment value when the motor speed value is greater than the second preset speed value, the second motor speed coefficient being less than the first motor speed coefficient.

[0042] In some embodiments, the adjusting module is further configured to determine an intermediate coefficient based on the motor speed value by using a first preset table, the first preset table being configured to record a plurality of motor speed values and an intermediate coefficient corresponding to each motor speed value, the intermediate coefficient being less than 1; and multiply the motor speed value and the intermediate coefficient to obtain the second motor speed coefficient.

[0043] In some embodiments, the device further comprises:

[0044] The determining module is configured to compare a first intermediate value and a second intermediate value to obtain the actual voltage utilization, the first intermediate value being configured to represent an output voltage value of a motor controller, and the second intermediate value being configured to represent an input voltage value of the motor controller.

[0045] In some embodiments, the determining module is further configured to determine, based on the motor torque value, a reference current value by using a second preset table, the second preset table being configured to record a plurality of motor torque values and a reference current value corresponding to each motor torque value.

[0046] In some embodiments, the reference current value includes a reference direct-axis current value and a reference quadrature-axis current value.

[0047] The driving module is configured to, in a case where the motor speed value of the permanent magnet synchronous motor is greater than a first preset speed value, add the reference direct-axis current value and the current adjustment value to obtain a target direct-axis current value; determine a target quadrature-axis current value based on the motor torque value and the target direct-axis current value; and in a case where the target direct-axis current value and the target quadrature-axis current value meet a preset condition, drive the permanent magnet synchronous motor to operate based on the target direct-axis current value and the target quadrature-axis current value.

[0048] In some embodiments, the reference current value includes a reference direct-axis current value and a reference quadrature-axis current value; the driving module is configured to, in a case where the motor speed value is not greater than the first preset speed value, determine the reference direct-axis current value as a target direct-axis current value and determine the reference quadrature-axis current value as a target quadrature-axis current value; and in a case where the target direct-axis current value and the target quadrature-axis current value meet a preset condition, drive the permanent magnet synchronous motor to operate based on the target direct-axis current value and the target quadrature-axis current value.

[0049] In some embodiments, the driving module is configured to determine, as a resultant current value, a square root value of a sum of the square of the target direct-axis current value and the square of the target quadrature-axis current value; and in a case where the resultant current value is not greater than a running current threshold value, drive the permanent magnet synchronous motor to operate based on the target direct-axis current value and the target quadrature-axis current value.

[0050] In some embodiments, the driving module is configured to, in a case where the resultant current value is greater than the running current threshold value, determine, as an updated target quadrature-axis current value, a square root value of a difference between the running current threshold value and the square of the target direct-axis current value, the updated target quadrature-axis current value being smaller than the target quadrature-axis current value; and drive the permanent magnet synchronous motor to operate based on the target direct-axis current value and the updated target quadrature-axis current value.

[0051] In another aspect, a computer device is provided, which includes a processor and a memory, the memory being configured to store at least one piece of computer program, the at least one piece of computer program being loaded and executed by the processor to implement the control method of the permanent magnet synchronous motor in the embodiments of the present application.

[0052] In another aspect, a computer readable storage medium is provided, and at least one piece of computer program is stored in the computer readable storage medium, and the at least one piece of computer program is loaded and executed by a processor to implement the control method of the permanent magnet synchronous motor in the embodiments of the present application.

[0053] In another aspect, a computer program product is provided, and the computer program product comprises a computer program, and the computer program is executed by a processor to implement the control method of the permanent magnet synchronous motor in the embodiments of the present application.

[0054] The present application provides a control method of a permanent magnet synchronous motor, in which a motor speed coefficient is introduced in the adjustment process of a PI regulator to obtain a current adjustment value. Since different motor speed coefficients correspond to different motor speed value intervals, the control method associates the obtained current adjustment value with a real-time motor speed value, so that a reasonable current adjustment value can be obtained based on the motor speed coefficient corresponding to the motor speed value interval in the case that the real-time motor speed value is located in each motor speed value interval. Through the above method, in the case that the real-time motor speed value changes rapidly, the current in the permanent magnet synchronous motor can also be adjusted rapidly and stably through the current adjustment value, so that the permanent magnet synchronous motor can be ensured to operate safely and rapidly. BRIEF DESCRIPTION OF DRAWINGS

[0055] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0056] Figure 1 is a flow chart of a control method of a permanent magnet synchronous motor according to an embodiment of the present application;

[0057] Figure 2 is a flow chart of another control method of a permanent magnet synchronous motor according to an embodiment of the present application;

[0058] Figure 3 is a schematic diagram of an overall process according to an embodiment of the present application;

[0059] Figure 4 is a block diagram of a control device of a permanent magnet synchronous motor according to an embodiment of the present application;

[0060] Figure 5 is a block diagram of another control device of a permanent magnet synchronous motor according to an embodiment of the present application;

[0061] Figure 6is a structural schematic diagram of a terminal according to an embodiment of the present application;

[0062] Figure 7 is a structural schematic diagram of a server according to an embodiment of the present application. DETAILED DESCRIPTION

[0063] For the purpose, technical solutions and advantages of the present application to be clearer, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0064] In the present application, the terms "first", "second", and the like are used to distinguish the same or similar items with substantially the same function and purpose, and it should be understood that there is no logical or time sequence dependency between "first", "second", and "n", and the number and execution order are not limited.

[0065] In the present application, the term "at least one" means one or more, and the term "multiple" means two or more.

[0066] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data for analysis, stored data, displayed data, etc.) and signals involved in the present application are all authorized by the user or fully authorized by all parties, and the collection, use and processing of related data need to comply with relevant laws, regulations and standards of relevant countries and regions. For example, the motor speed value, the motor torque value, the first preset table, the second preset table and the like involved in the present application are obtained under sufficient authorization.

[0067] Next, the terms appearing in the embodiments of the present application will be briefly introduced.

[0068] Direct-axis current value: refers to the current component flowing along the magnetic field axis direction of the rotor permanent magnet in the permanent magnet synchronous motor. The magnetic flux can be adjusted by adjusting the direct-axis current value.

[0069] Quadrature-axis current value: refers to the current component flowing perpendicular to the magnetic field axis direction of the rotor permanent magnet in the permanent magnet synchronous motor. The motor torque value can be adjusted by adjusting the quadrature-axis current value.

[0070] Direct-axis voltage value: refers to the voltage component applied to the stator winding of the permanent magnet synchronous motor and aligned with the magnetic field axis of the permanent magnet. The magnetic flux can be adjusted by adjusting the direct-axis voltage value.

[0071] Quadrature-axis voltage value: refers to the voltage component applied to the stator winding of the permanent magnet synchronous motor and perpendicular to the magnetic field axis of the permanent magnet. The motor torque value can be adjusted by adjusting the quadrature-axis voltage value.

[0072] DC bus voltage value: refers to the DC voltage of the input end of the inverter, which is usually provided by a DC power supply. The inverter is used to convert the DC bus voltage into an alternating voltage to drive the stator winding of the permanent magnet synchronous motor.

[0073] Direct-axis inductance value: refers to the inductance of the stator winding of the permanent magnet synchronous motor in the direct-axis direction, which can reflect the interaction effect between the magnetic field generated by the stator current in the direct-axis direction and the permanent magnet magnetic field.

[0074] Cross-axis inductance: refers to the inductance of the stator winding of the permanent magnet synchronous motor in the cross-axis direction, which can reflect the interaction effect between the magnetic field generated by the stator current in the cross-axis direction and the permanent magnet magnetic field.

[0075] Motor pole pair number: refers to the number of magnetic field polarity of the stator and rotor of the permanent magnet synchronous motor. The motor pole pair number is used to indicate the synchronous speed of the permanent magnet synchronous motor, i.e. the rotational speed at the rated frequency.

[0076] Permanent magnet flux linkage: refers to the chain effect value of the magnetic flux generated by the permanent magnet of the permanent magnet synchronous motor in the stator winding.

[0077] Figure 1 A flowchart of a control method of a permanent magnet synchronous motor is provided according to an embodiment of the present application. The method is executed by a control system of the permanent magnet synchronous motor, as shown in Figure 1 The method includes the following steps:

[0078] 101. The product of the voltage utilization difference and the motor speed coefficient is input into the PI regulator to obtain the current adjustment value. The voltage utilization difference is the difference between the actual voltage utilization and the reference voltage utilization. Different motor speed coefficients correspond to different motor speed value intervals.

[0079] In the embodiment of the present application, the PI (Proportional-Integral) regulator is a linear controller commonly used in control systems. The regulator adjusts the output parameter based on the input parameter through proportional control and integral control. In the embodiment of the present application, the input parameter of the regulator is the product of the voltage utilization difference and the motor speed coefficient. The output parameter of the regulator is the current adjustment value. The actual voltage utilization is used to indicate the utilization efficiency and degree of voltage by the motor controller. The reference voltage utilization refers to the theoretical voltage utilization, which is usually higher than the actual voltage utilization.

[0080] 102. When the motor speed value of the permanent magnet synchronous motor is greater than the first preset speed value, the permanent magnet synchronous motor is driven to operate based on the current adjustment value and the reference current value.

[0081] In the embodiment of the present application, the reference current value includes a reference direct-axis current value and a reference alternating current value. The reference current value is a current value determined based on the motor torque value. The reference current value includes a reference direct-axis current value and a reference alternating-axis current value. Generally, the reference direct-axis current value and the current adjustment value are both negative values.

[0082] When the motor speed value is greater than the first preset speed value, it can be considered that the motor speed value is in a high speed interval. At this time, the reference direct-axis current value is adjusted by the current adjustment value, so that the weakening effect of the magnetic field of the permanent magnet is better, that is, the depth of field weakening is increased.

[0083] 103、In the case where the motor speed value is not greater than the first preset speed value, the permanent magnet synchronous motor is driven to operate based on the reference current value.

[0084] In the embodiment of the present application, when the motor speed value is not greater than the first preset speed value, it can be considered that the motor speed value is in a low speed interval. At this time, the PI regulator is not required to perform the adjustment process, and the permanent magnet synchronous motor is directly driven to operate by the reference current value.

[0085] The embodiment of the present application provides a control method of a permanent magnet synchronous motor. In the method, a motor speed coefficient is introduced in the adjustment process of a PI regulator to obtain a current adjustment value. Since different motor speed coefficients correspond to different motor speed value intervals, the current adjustment value obtained by the above method is associated with the real-time motor speed value, so that when the real-time motor speed value is located in each motor speed value interval, a reasonable current adjustment value can be obtained based on the motor speed coefficient corresponding to the motor speed value interval. Through the above method, in the case where the real-time motor speed value changes rapidly, the current in the permanent magnet synchronous motor can also be quickly and stably adjusted by the current adjustment value, thereby ensuring that the permanent magnet synchronous motor operates safely and at high speed.

[0086] Figure 2 is a flowchart of another control method of a permanent magnet synchronous motor provided by the embodiment of the present application. The method is executed by a control system of the permanent magnet synchronous motor, and the method includes the following steps: Figure 2

[0087] 201、based on the motor torque value, determining a reference current value through a second preset table, the second preset table being used to record a plurality of motor torque values and a reference current value corresponding to each motor torque value.

[0088] ​In the embodiments of the present application, the control system determines the motor torque value of the permanent magnet synchronous motor according to the torque command, and then queries the reference current value corresponding to the motor torque value in the second preset table. The torque command is a command issued by the motor controller in the control system in the process of adjusting the parameter value of the operating parameter of the permanent magnet synchronous motor. The torque command carries the motor torque value of the permanent magnet synchronous motor. For example, in an automobile driving system, the torque command can be determined by the accelerator pedal position signal of the driver, and the torque command is used to control the permanent magnet synchronous motor to accelerate or decelerate.

[0089] The motor torque value refers to the parameter value of the motor torque. The motor torque refers to the torque generated by the permanent magnet synchronous motor when rotating, and can reflect the driving force provided by the permanent magnet synchronous motor and the load supported by the permanent magnet synchronous motor. The reference current value refers to the parameter value of the reference current. The reference current value includes the reference direct-axis current value and the reference quadrature-axis current value. That is, the reference current is used to drive the permanent magnet synchronous motor to operate. The reference current includes the reference direct-axis current and the reference quadrature-axis current. For ease of description, the reference direct-axis current can be referred to as d-axis current, and the reference direct-axis current value can be referred to as Id0; the reference quadrature-axis current can be referred to as q-axis current, and the reference quadrature-axis current value can be referred to as Iq0.

[0090] In order to make the permanent magnet synchronous motor reach a certain motor torque value during operation, the permanent magnet synchronous motor needs to be driven to operate according to the reference current value corresponding to the motor torque value. In the embodiments of the present application, the second preset table is used to record a plurality of motor torque values of the permanent magnet synchronous motor and the reference current value corresponding to each motor torque value. Optionally, the second preset table is an MTPA (Maximum Torque Per Ampere) table.

[0091] In some embodiments, the second preset table is made by a motor calibration bench in the control system. Correspondingly, a sampling speed value is obtained; the motor speed value is set to the sampling speed value through the motor calibration bench; and the reference direct-axis current value and the reference quadrature-axis current value corresponding to different motor torque values are obtained based on the MTPA control strategy, so as to obtain the second preset table.

[0092] The sampling speed value is less than the turning speed value. For example, the sampling speed value is set to 2 / 3 of the turning speed value. The turning speed value is the parameter value of the turning speed. The turning speed is used to indicate the motor speed value at which the permanent magnet synchronous motor enters the constant power stage from the constant torque stage. Since the constant torque stage to the constant power stage is a process of gradually accelerating the permanent magnet synchronous motor, the turning speed refers to the maximum motor speed value in the constant torque stage. The control strategy is used to obtain the optimal combination of the direct-axis current value and the quadrature-axis current value corresponding to different motor torque values of the permanent magnet synchronous motor.

[0093] It should be noted that the mapping relationship between the motor torque value of the permanent magnet synchronous motor and the reference current value is recorded through the second preset table, so that the reference current value can be quickly determined based on the real-time motor torque value through table lookup in the control process of the permanent magnet synchronous motor, and then the permanent magnet synchronous motor is driven to operate on this basis. The above-mentioned method is not only convenient and fast, but also can adapt to various operating states of the permanent magnet synchronous motor, and has high flexibility and accuracy.

[0094] 202、the actual voltage utilization rate is obtained by comparing the first intermediate value and the second intermediate value, and the voltage utilization rate difference is obtained by subtracting the actual voltage utilization rate from the reference voltage utilization rate, the first intermediate value is used to represent the output voltage value of the motor controller, and the second intermediate value is used to represent the input voltage value of the motor controller.

[0095] In the embodiment of the application, the actual voltage utilization rate is used to indicate the utilization efficiency and utilization degree of the voltage of the motor controller. The first intermediate value is the combined voltage value of the direct-axis voltage value and the quadrature-axis voltage value, and the second intermediate value is determined by the DC bus voltage value. The reference voltage utilization rate refers to the preset theoretical voltage utilization rate, and the reference voltage utilization rate is usually higher than the actual voltage utilization rate. For the convenience of description, the actual voltage utilization rate can be referred to as Vr1, and the reference voltage utilization rate can be referred to as Vr0.

[0096] For the convenience of describing the determination method of the actual voltage utilization rate, refer to the formula shown below.

[0097]

[0098] Wherein, V r1 is the actual voltage utilization rate, V d is the direct-axis voltage value, V q is the quadrature-axis voltage value, V dc is the DC bus voltage value. Accordingly, is the first intermediate value; is the second intermediate value.

[0099] It should be noted that the actual voltage utilization rate is determined based on the output voltage value and the input voltage value of the motor controller, which facilitates subsequent determination of the voltage utilization rate difference and the current adjustment value, and improves the intuitiveness and efficiency.

[0100] It should be noted that the above steps 201 and 202 are exemplary determination steps of the operating parameter value of the permanent magnet synchronous motor, and the determination order of the operating parameter value is not limited in the embodiment of the application. The operating parameter value of the permanent magnet synchronous motor is the parameter value of the operating parameter. Alternatively, the operating parameter includes the motor torque value, the motor speed value, the reference current value, the voltage utilization rate difference, etc.

[0101] 203. Input the product of the voltage utilization difference and the motor speed coefficient into the PI regulator to obtain the current adjustment value. Different motor speed coefficients correspond to different motor speed value ranges.

[0102] In this embodiment, the PI (Proportional-Integral) controller is a commonly used linear controller in control systems. This controller adjusts the output parameter based on the input parameter using both proportional and integral control methods. In this embodiment, the input parameter of the controller is the product of the voltage utilization difference and the motor speed coefficient. The output parameter of the controller is the current adjustment value.

[0103] In other words, compared to the traditional method, this embodiment adjusts the voltage utilization difference based on the motor speed coefficient before inputting the voltage utilization rate into the regulator. Since the motor speed coefficient is related to the motor speed of the permanent magnet synchronous motor, the above process can be regarded as linking the adjustment process of the PI regulator with the motor speed value.

[0104] In some embodiments, different motor speed coefficients are used to obtain the input parameters of the regulator when the motor speed value is in different motor speed value ranges. Accordingly, when the motor speed value is not greater than the second preset speed value, the product of the voltage utilization rate difference and the first motor speed coefficient is input to the PI regulator to obtain the current adjustment value; when the motor speed value is greater than the second preset speed value, the product of the voltage utilization rate difference and the second motor speed coefficient is input to the PI regulator to obtain the current adjustment value, wherein the second motor speed coefficient is less than the first motor speed coefficient.

[0105] For ease of description, the first motor speed coefficient can be referred to as k1, and the second motor speed coefficient can be referred to as k2. Typically, the first speed coefficient is set to 1, meaning that the voltage utilization rate difference does not need to be adjusted before being input into the regulator. The second speed coefficient is set to a value less than 1, meaning that the voltage utilization rate difference is adjusted to a lower value before being input into the regulator. Optionally, the second preset speed value can be set to 10000 rpm (revolutions per minute).

[0106] Optionally, the control system determines whether the motor speed is greater than a second preset speed value. If the motor speed is not greater than the second preset speed value, the motor speed coefficient is set to a first motor speed coefficient; if the motor speed is greater than the second preset speed value, the motor speed coefficient is set to a second motor speed coefficient.

[0107] It should be noted that by introducing the motor speed coefficient in the adjustment process of the PI regulator, and selecting different motor speed coefficients according to different motor speed value intervals in which the motor speed value is located, the current can be more accurately adjusted, thereby improving the response speed and stability of the permanent magnet synchronous motor. Correspondingly, the corresponding motor speed coefficient is determined according to the real-time motor speed value, and the input parameter of the PI regulator is adjusted through the motor speed coefficient, so that the current adjustment value obtained through the PI regulator is associated with the real-time motor speed value, and is more accurate and reasonable, thereby improving the response speed and stability of the permanent magnet synchronous motor.

[0108] In some embodiments, the second motor speed coefficient is determined according to the motor speed value. Correspondingly, based on the motor speed value, an intermediate coefficient is determined through a first preset table, the first preset table is used to record a plurality of motor speed values and an intermediate coefficient corresponding to each motor speed value, and the intermediate coefficient is less than 1; the motor speed value and the intermediate coefficient are multiplied to obtain the second motor speed coefficient.

[0109] For ease of description, the intermediate coefficient can be referred to as k. It should be noted that the above first preset table is only an exemplary description. Alternatively, the first preset table can record combinations of motor torque values and motor speed values, and intermediate coefficients corresponding to different combinations, which will not be described here.

[0110] It should be noted that the mapping relationship between the operating parameter value of the permanent magnet synchronous motor and the intermediate coefficient is recorded through the first preset table, which facilitates quick determination of the intermediate coefficient based on the operating parameter value in the control process of the permanent magnet synchronous motor, and further determination of the second motor speed coefficient. The above-mentioned method is not only convenient and fast, but also can adapt to various operating states of the permanent magnet synchronous motor, and has high flexibility and accuracy.

[0111] 204、In the case where the motor speed value of the permanent magnet synchronous motor is greater than the first preset speed value, the reference direct-axis current value and the current adjustment value are added to obtain the target direct-axis current value.

[0112] In the embodiments of the present application, the first preset speed value can be similar to the turning speed value. The target direct-axis current value is a negative value.

[0113] It should be noted that when the motor speed value is greater than the first preset speed value, it can be considered that the motor speed value is in the high speed interval. Generally, the reference direct axis current value and the current adjustment value are negative values, so compared with the reference direct axis current value, the target direct axis current value is smaller, that is, the direct axis current is increased. Because the direct axis current in the permanent magnet synchronous motor and the magnetic field generated by the permanent magnet are opposite, the magnetic field of the permanent magnet can be offset, thereby reducing the magnetic flux. Therefore, compared with the reference direct axis current value, when driving the permanent magnet synchronous motor by the target direct axis current value, the effect of reducing the magnetic flux is better, that is, the depth of field weakening is increased.

[0114] It should be noted that the size relationship between the first preset speed value and the second preset speed value is not limited in the embodiment of the application, and can be set by the person skilled in the art.

[0115] 205, based on the motor torque value and the target direct axis current value, determine the target quadrature axis current value.

[0116] In the embodiment of the application, when the target direct axis current value is determined, the target quadrature axis current value can be determined by the torque formula. It should be noted that because the current adjustment value is associated with the operating parameter value of the permanent magnet synchronous motor, when the motor speed value is greater than the first preset speed value, that is, when the motor speed value is in the high speed interval, the target direct axis current value is obtained by adding the reference direct axis current value and the current adjustment value, which realizes the adjustment of the current according to the operating parameter value of the permanent magnet synchronous motor, and improves the response speed and stability of the permanent magnet synchronous motor.

[0117] In order to facilitate the description of the determination method of the target quadrature axis current value, please refer to the formula shown below.

[0118]

[0119] Wherein, I q1 is the target quadrature axis current value, T is the motor torque value, p is the motor pole pair number, is the permanent magnet flux linkage, I d is the direct axis inductance value, L q is the quadrature axis inductance value, I d1 is the target direct axis current value. Wherein, the motor pole pair number, the permanent magnet flux linkage and other parameters are conventional parameters of the permanent magnet synchronous motor, which will not be described here.

[0120] 206, when the motor speed value is not greater than the first preset speed value, the reference direct axis current value is determined as the target direct axis current value, and the reference quadrature axis current value is determined as the target quadrature axis current value.

[0121] In the embodiment of the present application, when the motor speed value is not greater than the first preset speed value, it can be considered that the motor speed value is in the low speed interval. At this time, the reference current value is directly determined as the target current value without the adjustment process by the PI regulator. The target current value includes the target direct-axis current value and the target quadrature-axis current value.

[0122] Optionally, the control system determines whether the motor speed value is greater than the first preset speed value. In the case that the motor speed value is greater than the second preset speed value, steps 201 to 205 are executed, that is, the current adjustment value is obtained by the PI regulator, and then the target current value is obtained on the basis of the reference current value; in the case that the motor speed value is not greater than the first preset speed value, steps 201 and 206 are executed, that is, the reference current value is determined, and the reference current value is determined as the target current value.

[0123] It should be noted that in the case that the motor speed value is not greater than the first preset speed value, that is, when the motor speed value is in the low speed interval, the target direct-axis current value and the target quadrature-axis current value are directly determined, and in the case that the above two current values meet the preset condition, they are used as the current value for driving the permanent magnet synchronous motor to operate. The above-mentioned method is not only intuitive and efficient, but also simple, clear and easy to implement.

[0124] 207、The square root value of the sum of the target direct-axis current value and the target quadrature-axis current value is determined as the synthesis current value.

[0125] In the embodiment of the present application, the target direct-axis current value is used to control the magnetic flux of the permanent magnet synchronous motor, and the target quadrature-axis current value is used to control the torque value of the permanent magnet synchronous motor. The synthesis current value is the vector sum of the target direct-axis current value and the target quadrature-axis current value, and the synthesis current value is used to indicate the total current in the permanent magnet synchronous motor.

[0126] In order to describe the determination method of the synthesis current value, refer to the formula shown below.

[0127]

[0128] Wherein, I s is the synthesis current value, I d1 is the target direct-axis current value, I q1 is the target quadrature-axis current value.

[0129] 208、In the case that the synthesis current value is not greater than the operating current threshold value, the permanent magnet synchronous motor is driven to operate based on the target direct-axis current value and the target quadrature-axis current value.

[0130] In the embodiment of the present application, the operating current threshold value is the maximum working current value of the permanent magnet synchronous motor. For ease of description, the operating current threshold value can be referred to as Imax.

[0131] When the synthetic current value is not greater than the operating current threshold, that is, the synthetic current value is within the current limit circle, it indicates that the synthetic current value is within the normal operating range of the permanent magnet synchronous motor at this time, and thus the permanent magnet synchronous motor can be directly driven to operate based on the target direct-axis current value and the target quadrature-axis current value.

[0132] It should be noted that by comparing the synthetic current value and the operating current threshold, the situation that the permanent magnet synchronous motor is damaged due to excessive current can be avoided, and the stability and safety of the permanent magnet synchronous motor are improved.

[0133] 209、In the case where the synthetic current value is greater than the operating current threshold, the square root of the difference between the operating current threshold and the target direct-axis current value is determined as the updated target quadrature-axis current value.

[0134] In the embodiment of the present application, the updated target quadrature-axis current value is smaller than the target quadrature-axis current value. When the synthetic current value is greater than the operating current threshold, that is, the synthetic current value exceeds the current limit circle, it indicates that the synthetic current value exceeds the normal operating range of the permanent magnet synchronous motor at this time, which may cause the permanent magnet synchronous motor to be damaged due to overload. Therefore, the target current value needs to be updated. In order to guarantee the depth of field weakening, the target direct-axis current value used to adjust the depth of field weakening is kept unchanged, and the target quadrature-axis current value is adjusted to be smaller based on the operating current threshold.

[0135] In order to facilitate the description of the updating process of the target quadrature-axis current value, refer to the following formula.

[0136]

[0137] Wherein, I q1 is the updated target quadrature-axis current value, I max is the operating current threshold, I d1 is the target direct-axis current value.

[0138] It should be noted that by adjusting the target quadrature-axis current value, the synthetic current value determined based on the target direct-axis current value and the target quadrature-axis current value can be prevented from exceeding the operating current threshold, that is, the safe operating range of the permanent magnet synchronous motor is avoided, and the safety of the permanent magnet synchronous motor is improved. At the same time, since only the target quadrature-axis current value is adjusted while the target direct-axis current value is kept unchanged, the adjustment effect on the air gap magnetic field of the permanent magnet synchronous motor and the adjustment effect on the back electromotive force of the permanent magnet synchronous motor are guaranteed, and the motor speed value can be more efficiently improved.

[0139] 210、Based on the target direct-axis current value and the updated target quadrature-axis current value, the permanent magnet synchronous motor is driven to operate.

[0140] In this embodiment, by using an updated target quadrature-axis current value to drive the permanent magnet synchronous motor, the combined current value is ensured to be within the current limit circle, thus guaranteeing the safety of the permanent magnet synchronous motor.

[0141] Meanwhile, since the target direct-axis current value and the target AC current value are related to the operating parameters of the permanent magnet synchronous motor, the target direct-axis current value and the target AC current value can be determined based on the real-time operating status of the permanent magnet synchronous motor, and the permanent magnet synchronous motor can be driven to run, thus improving the response speed and flexibility.

[0142] For a clearer description of the overall process, please refer to [link / reference]. Figure 3 As shown, Figure 3 This is a schematic diagram of an overall process according to an embodiment of this application. The control method in this embodiment is executed by the control system of a permanent magnet synchronous motor. First, step 301 is executed: based on the motor torque value, the reference direct-axis current value and the reference quadrature-axis current value are obtained by looking up a table. Step 302 is executed: the actual voltage utilization rate is calculated in real time, and the difference between the actual voltage utilization rate and the reference voltage utilization rate is obtained as the voltage utilization rate difference value. Step 303 is executed: it is determined whether the motor speed value is greater than a second preset speed value. If it is greater, step 304 is executed: the motor speed coefficient is set to the second motor speed coefficient; if it is not greater, step 305 is executed: the motor speed coefficient is set to the first motor speed coefficient. Then, step 306 is executed: the product of the voltage utilization rate difference and the motor speed coefficient is used as the input parameter of the PI regulator. Step 307 is executed: the current adjustment value is output through the PI regulator. Step 308 is executed: it is determined whether the motor speed value is greater than the first preset speed value. If the value is greater than the target value, proceed to step 309, using the sum of the reference direct-axis current value and the current adjustment value as the target direct-axis current value; proceed to step 310, calculating the target quadrature-axis current value according to the torque formula. If the value is not greater than the target value, proceed to step 311, determining the reference direct-axis current value as the target direct-axis current value and the reference quadrature-axis current value as the target quadrature-axis current value. Then proceed to step 312, determining whether the combined current value is greater than the operating current threshold. If the value is greater than the target value, proceed to step 313, keeping the target direct-axis current value unchanged, and recalculating the target quadrature-axis current value according to the operating current threshold; proceed to step 314, driving the permanent magnet synchronous motor using the target direct-axis current value and the target quadrature-axis current value. If the value is not greater than the target value, proceed to step 314, driving the permanent magnet synchronous motor using the target direct-axis current value and the target quadrature-axis current value.

[0143] In some embodiments, the control system comprises a motor calibration bench, a motor controller, and a permanent magnet synchronous motor. The motor calibration bench is configured to simulate an operating environment of the permanent magnet synchronous motor. The motor controller is configured to control parameter values of operating parameters of the permanent magnet synchronous motor, the operating parameters comprising a motor torque value and a motor speed value. The permanent magnet synchronous motor is configured to operate under the control of the motor controller. Optionally, other computer devices are included in the control system, which are not limited herein.

[0144] Optionally, the motor calibration bench is configured to obtain parameters in the first preset table and the second preset table. Optionally, the motor controller is the execution subject of steps 201 to 210, and the motor controller is configured to determine the target direct-axis current value and the target quadrature-axis current value based on the operating state of the permanent magnet synchronous motor, and then drive the permanent magnet synchronous motor to operate.

[0145] The embodiments of the present application provide a control method of a permanent magnet synchronous motor. In the method, a motor speed coefficient is introduced in the adjustment process of a PI regulator to obtain a current adjustment value. Since different motor speed coefficients correspond to different motor speed value intervals, the current adjustment value obtained by the above method is associated with the real-time motor speed value, so that a reasonable current adjustment value can be obtained based on the motor speed coefficient corresponding to the motor speed value interval in the case that the real-time motor speed value is located in each motor speed value interval. Through the above method, in the case that the real-time motor speed value changes rapidly, the current in the permanent magnet synchronous motor can also be quickly and stably adjusted through the current adjustment value, thereby ensuring that the permanent magnet synchronous motor operates safely and rapidly.

[0146] Figure 4 is a block diagram of a control device of a permanent magnet synchronous motor according to the embodiments of the present application. The device is configured to perform the steps of the control method of the permanent magnet synchronous motor described above, and the control method of the permanent magnet synchronous motor is described in detail with reference to Figure 4 The control device of the permanent magnet synchronous motor comprises an adjustment module 401 and a driving module 402.

[0147] The adjustment module 401 is configured to input a product value of a voltage utilization difference and a motor speed coefficient into a PI regulator to obtain a current adjustment value. The voltage utilization difference is a difference between an actual voltage utilization and a reference voltage utilization. Different motor speed coefficients correspond to different motor speed value intervals.

[0148] The driving module 402 is configured to drive the permanent magnet synchronous motor to operate based on the current adjustment value and a reference current value in the case that the motor speed value of the permanent magnet synchronous motor is greater than a first preset speed value.

[0149] The driving module 402 is further configured to drive the permanent magnet synchronous motor to operate based on the reference current value in the case that the motor speed value is not greater than the first preset speed value.

[0150] In some embodiments, the adjusting module 402 is configured to, in a case where the motor speed value is not greater than a second preset speed value, input a product value of the voltage utilization difference and a first motor speed coefficient into a PI regulator to obtain a current adjustment value; and in a case where the motor speed value is greater than the second preset speed value, input a product value of the voltage utilization difference and a second motor speed coefficient into the PI regulator to obtain the current adjustment value, the second motor speed coefficient being less than the first motor speed coefficient.

[0151] In some embodiments, the adjusting module 402 is further configured to, based on the motor speed value, determine an intermediate coefficient by using a first preset table, the first preset table being configured to record a plurality of motor speed values and an intermediate coefficient corresponding to each motor speed value, the intermediate coefficient being less than 1; and multiply the motor speed value and the intermediate coefficient to obtain the second motor speed coefficient.

[0152] In some embodiments, Figure 5 is a block diagram of another control device of a permanent magnet synchronous motor according to an embodiment of the present application. The device further includes:

[0153] The determining module 501 is configured to divide a first intermediate value by a second intermediate value to obtain an actual voltage utilization, the first intermediate value being configured to represent an output voltage value of the motor controller, and the second intermediate value being configured to represent an input voltage value of the motor controller.

[0154] In some embodiments, the determining module 501 is further configured to, based on the motor torque value, determine the reference current value by using a second preset table, the second preset table being configured to record a plurality of motor torque values and a reference current value corresponding to each motor torque value.

[0155] In some embodiments, the reference current value includes a reference direct-axis current value and a reference quadrature-axis current value.

[0156] The driving module 402 is configured to, in a case where the motor speed value of the permanent magnet synchronous motor is greater than a first preset speed value, add the reference direct-axis current value and the current adjustment value to obtain a target direct-axis current value; determine a target quadrature-axis current value based on the motor torque value and the target direct-axis current value; and in a case where the target direct-axis current value and the target quadrature-axis current value meet a preset condition, drive the permanent magnet synchronous motor to operate based on the target direct-axis current value and the target quadrature-axis current value.

[0157] In some embodiments, the reference current value includes a reference direct-axis current value and a reference quadrature-axis current value.

[0158] The driving module 402 is configured to determine the reference direct-axis current value as the target direct-axis current value and determine the reference quadrature-axis current value as the target quadrature-axis current value when the motor speed value is not greater than the first preset speed value; and drive the permanent magnet synchronous motor to operate based on the target direct-axis current value and the target quadrature-axis current value when the target direct-axis current value and the target quadrature-axis current value meet a preset condition.

[0159] In some embodiments, the driving module 402 is configured to determine a square root value of a sum of the square of the target direct-axis current value and the square of the target quadrature-axis current value as a synthetic current value; and drive the permanent magnet synchronous motor to operate based on the target direct-axis current value and the target quadrature-axis current value when the synthetic current value is not greater than an operating current threshold value.

[0160] In some embodiments, the driving module 402 is configured to determine a square root value of a difference between the operating current threshold value and the square of the target direct-axis current value as an updated target quadrature-axis current value when the synthetic current value is greater than the operating current threshold value, the updated target quadrature-axis current value being less than the target quadrature-axis current value; and drive the permanent magnet synchronous motor to operate based on the target direct-axis current value and the updated target quadrature-axis current value.

[0161] The control device for the permanent magnet synchronous motor provided in the present application introduces a motor speed coefficient in the adjustment process of the PI regulator to obtain a current adjustment value. Since different motor speed coefficients correspond to different motor speed value intervals, the control device associates the obtained current adjustment value with the real-time motor speed value, so that a reasonable current adjustment value can be obtained based on the motor speed coefficient corresponding to the motor speed value interval when the real-time motor speed value is located in each motor speed value interval. Through the control device, the current in the permanent magnet synchronous motor can be quickly and stably adjusted through the current adjustment value when the real-time motor speed value changes rapidly, thereby ensuring that the permanent magnet synchronous motor operates safely and at high speed.

[0162] It should be noted that the control device for the permanent magnet synchronous motor provided in the above embodiments is only exemplified by the division of the above functional modules in the running application, and in actual application, the above functions can be completed by different functional modules according to needs, that is, the internal structure of the terminal is divided into different functional modules to complete all or part of the above described functions. In addition, the control device for the permanent magnet synchronous motor and the control method for the permanent magnet synchronous motor provided in the above embodiments belong to the same concept, and the implementation process is shown in the method embodiments, which will not be described here.

[0163] Figure 6is a structural schematic diagram of a terminal according to an embodiment of the present application. The terminal 600 can be a portable mobile terminal, such as a smartphone, a tablet computer, an MP3 player (Moving Picture Experts Group Audio Layer III), an MP4 (Moving Picture Experts Group Audio Layer IV) player, a notebook computer, or a desktop computer. The terminal 600 can also be referred to as a user equipment, a portable terminal, a laptop terminal, a desktop terminal, or other names.

[0164] Generally, the terminal 600 includes a processor 601 and a memory 602.

[0165] The processor 601 can include one or more processing cores, such as a 4-core processor, an 8-core processor, and the like. The processor 601 can be implemented in at least one of a hardware form of a DSP (Digital Signal Processing), an FPGA (Field-Programmable Gate Array), a PLA (Programmable Logic Array). The processor 601 can also include a main processor and a coprocessor, the main processor being a processor for processing data in an awake state, also referred to as a CPU (Central Processing Unit), and the coprocessor being a low-power processor for processing data in a standby state. In some embodiments, the processor 601 can be integrated with a GPU (Graphics Processing Unit) for rendering and drawing a volume cloud of content required to be displayed by a display screen. In some embodiments, the processor 601 can further include an AI (Artificial Intelligence) processor for processing computing operations related to machine learning.

[0166] The memory 602 can include one or more computer-readable storage media, which can be non-transitory. The memory 602 can also include a high-speed random access memory, and a non-volatile memory such as one or more disk storage devices, flash storage devices. In some embodiments, the non-transitory computer-readable storage medium in the memory 602 is used to store at least one computer program for being executed by the processor 601 to implement the control method of the permanent magnet synchronous motor provided by the method embodiment of the present application.

[0167] In some embodiments, terminal 600 can further include a peripheral device interface 603 and at least one peripheral device. The processor 601, the memory 602, and the peripheral device interface 603 can be connected through a bus or a signal line. Each peripheral device can be connected to the peripheral device interface 603 through a bus, a signal line, or a circuit board. The peripheral devices include at least one of a radio frequency circuit 604, a display screen 605, a camera component 606, an audio circuit 607, and a power supply 608.

[0168] The peripheral device interface 603 can be used to connect at least one peripheral device related to I / O (Input / Output) to the processor 601 and the memory 602. In some embodiments, the processor 601, the memory 602, and the peripheral device interface 603 are integrated on the same chip or circuit board; in some other embodiments, any one or two of the processor 601, the memory 602, and the peripheral device interface 603 can be implemented on a separate chip or circuit board, and the present embodiments are not limited in this regard.

[0169] The radio frequency circuit 604 is used to receive and transmit RF (Radio Frequency) signals, also known as electromagnetic signals. The radio frequency circuit 604 communicates with a communication network and other communication devices through electromagnetic signals. The radio frequency circuit 604 converts electrical signals into electromagnetic signals for transmission, or converts received electromagnetic signals into electrical signals. In some embodiments, the radio frequency circuit 604 includes an antenna system, an RF transceiver, one or more amplifiers, a tuner, an oscillator, a digital signal processor, a codec chipset, a subscriber identity module card, and the like. The radio frequency circuit 604 can communicate with other terminals through at least one wireless communication protocol. The wireless communication protocol includes but is not limited to the World Wide Web, a metropolitan area network, an intranet, various generations of mobile communication networks (2G, 3G, 4G, and 5G), a wireless local area network, and / or a WiFi (Wireless Fidelity) network. In some embodiments, the radio frequency circuit 604 can also include NFC (Near Field Communication) related circuitry, and the present application is not limited in this regard.

[0170] The display screen 605 is configured to display a UI (User Interface). The UI can include graphics, text, icons, video, and any combination thereof. When the display screen 605 is a touch display screen, the display screen 605 is further configured to capture touch signals on or above the surface of the display screen 605. The touch signals can be input to the processor 601 as control signals for processing. In this case, the display screen 605 can also be configured to provide virtual buttons and / or virtual keyboard, also known as soft buttons and / or soft keyboard. In some embodiments, the display screen 605 can be one, disposed on the front panel of the terminal 600; in other embodiments, the display screen 605 can be at least two, respectively disposed on different surfaces of the terminal 600 or in a folding design; in other embodiments, the display screen 605 can be a flexible display screen, disposed on a curved surface or a folding surface of the terminal 600. Even, the display screen 605 can also be disposed in an irregular shape other than a rectangle, i.e., a special-shaped screen. The display screen 605 can be made of LCD (Liquid Crystal Display), OLED (Organic Light-Emitting Diode), etc.

[0171] The camera assembly 606 is configured to capture images or videos. In some embodiments, the camera assembly 606 includes a front camera and a rear camera. Generally, the front camera is disposed on the front panel of the terminal, and the rear camera is disposed on the back of the terminal. In some embodiments, the rear camera is at least two, which are any one of a main camera, a depth-of-field camera, a wide-angle camera, and a telephoto camera, to realize the background blur function by fusing the main camera and the depth-of-field camera, the panoramic shooting and VR (Virtual Reality) shooting function by fusing the main camera and the wide-angle camera, or other fusion shooting functions. In some embodiments, the camera assembly 606 can further include a flash. The flash can be a single-color-temperature flash or a dual-color-temperature flash. The dual-color-temperature flash refers to the combination of a warm light flash and a cold light flash, which can be used for light compensation under different color temperatures.

[0172] The audio circuit 607 can include a microphone and a speaker. The microphone is used to collect sound waves of the user and the environment, and convert the sound waves into an electrical signal input to the processor 601 for processing, or input to the radio frequency circuit 604 to realize voice communication. For the purpose of stereo sound collection or noise reduction, the microphone can be multiple, respectively arranged at different parts of the terminal 600. The microphone can also be an array microphone or an omnidirectional collection type microphone. The speaker is used to convert the electrical signal from the processor 601 or the radio frequency circuit 604 into sound waves. The speaker can be a conventional diaphragm speaker, or a piezoelectric ceramic speaker. When the speaker is a piezoelectric ceramic speaker, not only can the electrical signal be converted into a sound wave that humans can hear, but also can be converted into a sound wave that humans cannot hear for ranging purposes. In some embodiments, the audio circuit 607 can also include a headphone jack.

[0173] The power supply 608 is used to supply power to each component in the terminal 600. The power supply 608 can be alternating current, direct current, disposable battery or rechargeable battery. When the power supply 608 includes a rechargeable battery, the rechargeable battery can support wired charging or wireless charging. The rechargeable battery can also be used to support fast charging technology.

[0174] In some embodiments, the terminal 600 also includes one or more sensors 609. The one or more sensors 609 include, but are not limited to, an acceleration sensor 610, a gyroscope sensor 611, a pressure sensor 612, an optical sensor 613, and a proximity sensor 614.

[0175] The acceleration sensor 610 can detect the acceleration in three coordinate axes of the coordinate system established by the terminal 600. For example, the acceleration sensor 610 can be used to detect the components of the gravitational acceleration in three coordinate axes. The processor 601 can control the display screen 605 to display the user interface in a landscape view or a portrait view according to the gravitational acceleration signal collected by the acceleration sensor 610. The acceleration sensor 610 can also be used for game or user motion data collection.

[0176] The gyroscope sensor 611 can detect the body direction and rotation angle of the terminal 600, and the gyroscope sensor 611 can collect 3D actions of the user on the terminal 600 in cooperation with the acceleration sensor 610. The processor 601 can realize the following functions according to the data collected by the gyroscope sensor 611: motion sensing (such as changing the UI according to the user's tilt operation), image stabilization when shooting, game control, and inertial navigation.

[0177] The pressure sensor 612 can be arranged at the side frame of the terminal 600 and / or the lower layer of the display screen 605. When the pressure sensor 612 is arranged at the side frame of the terminal 600, the holding signal of the user to the terminal 600 can be detected, and the left-hand or right-hand recognition or shortcut operation can be performed by the processor 601 according to the holding signal collected by the pressure sensor 612. When the pressure sensor 612 is arranged at the lower layer of the display screen 605, the operability control on the UI interface can be controlled by the processor 601 according to the pressure operation of the user to the display screen 605. The operability control includes at least one of the button control, the scroll bar control, the icon control and the menu control.

[0178] The optical sensor 613 is used to collect the ambient light intensity. In one embodiment, the processor 601 can control the display brightness of the display screen 605 according to the ambient light intensity collected by the optical sensor 613. Alternatively, the display brightness of the display screen 605 can be increased when the ambient light intensity is high, and the display brightness of the display screen 605 can be decreased when the ambient light intensity is low. In another embodiment, the processor 601 can also dynamically adjust the shooting parameter of the camera assembly 606 according to the ambient light intensity collected by the optical sensor 613.

[0179] The proximity sensor 614, also referred to as the distance sensor, is arranged at the front panel of the terminal 600. The proximity sensor 614 is used to collect the distance between the user and the front of the terminal 600. In one embodiment, the display screen 605 can be switched from the bright screen state to the screen-off state by the processor 601 when the proximity sensor 614 detects that the distance between the user and the front of the terminal 600 gradually decreases, and the display screen 605 can be switched from the screen-off state to the bright screen state by the processor 601 when the proximity sensor 614 detects that the distance between the user and the front of the terminal 600 gradually increases.

[0180] Those skilled in the art can understand that the structure shown in the above embodiments is not a limitation on the terminal 600, and the terminal 600 can include more or less components than the structure shown in the above embodiments, or some components can be combined, or different component arrangement can be adopted. Figure 6

[0181] Figure 7 ​A structural schematic diagram of a server is provided according to an embodiment of the present application. The server 700 can have great differences due to different configurations or performances, and can include one or more processors (Central Processing Units, CPUs) 701 and one or more memories 702. The memory 702 stores at least one computer program, which is loaded and executed by the processor 701 to implement the control method of the permanent magnet synchronous motor provided by each method embodiment. Of course, the server can also have a wired or wireless network interface, a keyboard, an input and output interface, and other components for implementing device functions, and the like, so as to perform input and output. The server can also include other components for implementing device functions, which are not described here.

[0182] The embodiment of the present application further provides a computer readable storage medium, which stores at least one computer program. The at least one computer program is loaded and executed by a processor to implement the control method of the permanent magnet synchronous motor in the above embodiment. For example, the computer readable storage medium can be a Read-Only Memory (ROM), a Random Access Memory (RAM), a Compact Disc Read-Only Memory (CD-ROM), a magnetic tape, a floppy disk, an optical data storage device, and the like.

[0183] The embodiment of the present application further provides a computer program product, which includes a computer program. The computer program is executed by a processor to implement the control method of the permanent magnet synchronous motor in the embodiment of the present application.

[0184] Those skilled in the art can understand that all or part of the steps of the above-mentioned embodiments can be completed by hardware, or by a program instructing relevant hardware to complete, and the program can be stored in a computer readable storage medium. The storage medium mentioned above can be a Read-Only Memory, a magnetic disk or an optical disk, and the like.

[0185] The above is only an optional embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A control method of a permanent magnet synchronous motor, characterized by, The method comprises: The product value of the voltage utilization difference value and the motor speed coefficient is input into a PI regulator to obtain a current adjustment value, the voltage utilization difference value is the difference between the actual voltage utilization and the reference voltage utilization, and different motor speed coefficients correspond to different motor speed value intervals; In a case where the motor speed value of the permanent magnet synchronous motor is greater than a first preset speed value, the permanent magnet synchronous motor is driven to operate based on the current adjustment value and a reference current value; In a case where the motor speed value is not greater than the first preset speed value, the permanent magnet synchronous motor is driven to operate based on the reference current value; The reference current value comprises a reference direct-axis current value and a reference quadrature-axis current value; In the case where the motor speed value is greater than the first preset speed value, the reference direct-axis current value and the current adjustment value are added to obtain a target direct-axis current value, a target quadrature-axis current value is determined based on a motor torque value and the target direct-axis current value, and in a case where the target direct-axis current value and the target quadrature-axis current value meet a preset condition, the permanent magnet synchronous motor is driven to operate based on the target direct-axis current value and the target quadrature-axis current value; In the case where the motor speed value is not greater than the first preset speed value, the reference direct-axis current value is determined as the target direct-axis current value, the reference quadrature-axis current value is determined as the target quadrature-axis current value, and in a case where the target direct-axis current value and the target quadrature-axis current value meet a preset condition, the permanent magnet synchronous motor is driven to operate based on the target direct-axis current value and the target quadrature-axis current value; In the case where the target direct-axis current value and the target quadrature-axis current value meet the preset condition, a square root value of the sum of the squares of the target direct-axis current value and the target quadrature-axis current value is determined as a synthetic current value, and in a case where the synthetic current value is not greater than an operating current threshold value, the permanent magnet synchronous motor is driven to operate based on the target direct-axis current value and the target quadrature-axis current value. The product value of the voltage utilization difference value and the motor speed coefficient is input into a PI regulator to obtain a current adjustment value, the voltage utilization difference value is the difference between the actual voltage utilization and the reference voltage utilization, and different motor speed coefficients correspond to different motor speed value intervals; In a case where the motor speed value is not greater than a second preset speed value, the product value of the voltage utilization difference value and a first motor speed coefficient is input into a PI regulator to obtain a current adjustment value; In a case where the motor speed value is greater than the second preset speed value, the product value of the voltage utilization difference value and a second motor speed coefficient is input into a PI regulator to obtain a current adjustment value, and the second motor speed coefficient is smaller than the first motor speed coefficient.

2. The method of claim 1, wherein, The method further comprises: ​ ​ 3. The method of claim 2, wherein, ​ Determine an intermediate coefficient based on the motor speed value by using a first preset table, the first preset table being configured to record a plurality of motor speed values and an intermediate coefficient corresponding to each motor speed value, the intermediate coefficient being less than 1; Multiply the motor speed value and the intermediate coefficient to obtain the second motor speed coefficient.

4. The method of claim 1, wherein, The method further comprises: Obtain the actual voltage utilization rate by taking a ratio of a first intermediate value and a second intermediate value, the first intermediate value being configured to represent an output voltage value of a motor controller, and the second intermediate value being configured to represent an input voltage value of the motor controller.

5. The method of claim 1, wherein, The method further comprises: Determine a reference current value based on a motor torque value by using a second preset table, the second preset table being configured to record a plurality of motor torque values and a reference current value corresponding to each motor torque value.

6. The method of claim 1, wherein, The method further comprises: In a case where the synthesized current value is greater than the operating current threshold value, determine an updated target quadrature-axis current value by taking a square root of a difference between the operating current threshold value and the target direct-axis current value, the updated target quadrature-axis current value being less than the target quadrature-axis current value; Drive the permanent magnet synchronous motor to operate based on the target direct-axis current value and the updated target quadrature-axis current value.

7. A control system of a permanent magnet synchronous motor, characterized by, A control system for implementing a control method of a permanent magnet synchronous motor according to any one of claims 1 to 6, the control system comprising a motor calibration bench, a motor controller, and a permanent magnet synchronous motor; The motor calibration bench is configured to simulate an operating environment of the permanent magnet synchronous motor; The motor controller is configured to control parameter values of operating parameters of the permanent magnet synchronous motor, the operating parameters comprising a motor torque value and a motor speed value; The permanent magnet synchronous motor is configured to operate under control of the motor controller.

8. A control device of a permanent magnet synchronous motor characterized by comprising: The apparatus comprises: An adjustment module configured to input a product value of a voltage utilization rate difference value and a motor speed coefficient into a PI adjuster to obtain a current adjustment value, the voltage utilization rate difference value being a difference between an actual voltage utilization rate and a reference voltage utilization rate, different motor speed coefficients corresponding to different motor speed value intervals; A driving module configured to drive the permanent magnet synchronous motor to operate based on the current adjustment value and a reference current value in a case where a motor speed value of the permanent magnet synchronous motor is greater than a first preset speed value; The driving module is further configured to drive the permanent magnet synchronous motor to operate based on the reference current value in a case where the motor speed value is not greater than the first preset speed value; The reference current value comprises a reference direct-axis current value and a reference quadrature-axis current value; The driving module is configured to add the reference direct-axis current value and the current adjustment value to obtain a target direct-axis current value in a case where the motor speed value is greater than the first preset speed value, determine a target quadrature-axis current value based on a motor torque value and the target direct-axis current value, and drive the permanent magnet synchronous motor to operate based on the target direct-axis current value and the target quadrature-axis current value in a case where the target direct-axis current value and the target quadrature-axis current value meet a preset condition. The driving module is configured to determine the reference direct-axis current value as a target direct-axis current value and determine the reference quadrature-axis current value as a target quadrature-axis current value when the motor speed value is not greater than the first preset speed value; and drive the permanent magnet synchronous motor to operate based on the target direct-axis current value and the target quadrature-axis current value when the target direct-axis current value and the target quadrature-axis current value meet a preset condition. The driving module is configured to determine a square root value of a sum of the target direct-axis current value and the target quadrature-axis current value as a composite current value; and drive the permanent magnet synchronous motor to operate based on the target direct-axis current value and the target quadrature-axis current value when the composite current value is not greater than an operating current threshold.

9. A computer device, comprising: The computer device comprises a processor and a memory, the memory is used to store at least one computer program, the at least one computer program is loaded and executed by the processor to execute the control method of the permanent magnet synchronous motor according to any one of claims 1 to 6.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium is used to store at least one computer program, the at least one computer program is used to execute the control method of the permanent magnet synchronous motor according to any one of claims 1 to 6.

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