Motor control method, device and system and wind power generation equipment

Abstract

The invention provides a motor control method, device and system and wind power generation equipment, and is applied to a control system of a motor, and the control system comprises an upper-layer controller and a plurality of lower-layer controllers which are in communication connection. The upper layer controller is used for the control loop to determine a wave-emitting voltage value of the motor according to the control frequency, the phase locking angle and the sampling value, obtain a wave-emitting voltage carrier wave comparison value according to the wave-emitting voltage value and an SVPWM wave-emitting mode and synchronize the wave-emitting voltage carrier wave comparison value to each lower layer controller, and the control frequency and the acquisition frequency of the sampling value are multiple times of the carrier wave frequency of the motor; and each lower-layer controller transmits waves in an SVPWM (Space Vector Pulse Width Modulation) wave transmission mode according to the converted new wave transmission voltage carrier wave comparison value so as to realize torque control on the motor. The sampling frequency and the control frequency are improved, the carrier frequency is kept unchanged, the response speed of the control system is improved, the switching loss is not increased, the control bandwidth is effectively improved, the influence of sampling and control delay caused by low original switching frequency on the system stability is effectively reduced, and the system stability is ensured.

Description

Technical Field

[0001] The present application relates to the field of control technology, and in particular to a motor control method, device, system and wind power generation equipment. Background Art

[0002] High-frequency permanent magnet motors are widely used in various equipment, such as wind power generation equipment. At present, for the torque control of high-frequency permanent magnet motors, from the perspective of improving system response time and enhancing stability, the sampling frequency and control frequency are required to be as high as possible. However, due to the system execution time and processor execution speed, the sampling and control speeds are limited.

[0003] The related technology can achieve the effect of increasing the control bandwidth to a certain extent by increasing the carrier frequency, that is, increasing the sampling frequency, control frequency and carrier frequency. However, since the switching frequency is increased by increasing the carrier frequency, the switching loss will increase and the service life of the switch will be reduced. In addition, if the sampling frequency, control frequency and carrier frequency remain unchanged, and the control bandwidth is increased by modifying the control parameters and phase-locked loop control parameters, this solution can stably control the permanent magnet motor to a certain extent. However, as the speed, that is, the carrier frequency, continues to increase, the bandwidth improvement brought by parameter adjustment cannot fully meet the bandwidth requirements brought by the speed increase. Therefore, parameter adjustment cannot completely solve the problem.

[0004] It can be seen that the relevant technology is not ideal for the torque control effect of high-frequency permanent magnet motors. Summary of the invention

[0005] The present application provides a motor control method, device, system and wind power generation equipment, which are used to overcome the technical problem of unsatisfactory control effect of torque control of high-frequency permanent magnet motors in related technologies.

[0006] In a first aspect, the present application provides a motor control method, which is applied to a control system of the motor, wherein the control system includes an upper controller and multiple lower controllers, and the upper controller is respectively connected to each lower controller for communication; the method includes:

[0007] The upper controller is used for the control loop to determine the wave voltage value of the motor according to the control frequency, the phase-locked angle and the sampling value, and obtain the wave voltage carrier comparison value according to the wave voltage value according to the SVPWM wave mode, and the control frequency and the acquisition frequency of the sampling value are multiples of the motor carrier frequency;

[0008] The upper controller synchronizes the wave voltage carrier comparison value to each lower controller, and each lower controller uses the SVPWM wave generation method to generate a new wave voltage carrier comparison value obtained after conversion of the wave voltage carrier comparison value to control the torque of the motor.

[0009] In a possible design, before the upper controller is used to control the loop to determine the wave voltage value of the motor according to the control frequency according to the phase-locked angle and the sampling value, it also includes:

[0010] The upper controller acquires the sampled values ​​collected at the collection frequency, wherein the sampled values ​​include a sampled current and a sampled voltage;

[0011] The upper controller performs phase-locked control in a phase-locked loop by using a back-electromotive force recognition method, so as to obtain the phase-locked angle according to a phase-locked gain coefficient.

[0012] In a possible design, the upper controller uses the back-electromotive force identification method to perform phase-locked control in a phase-locked loop to obtain the phase-locked angle according to the phase-locked gain coefficient, including:

[0013] The upper controller performs PI control on the back electromotive force and the preset voltage deviation of the motor, and obtains the phase-locking angle of each beat of the motor according to the output of the PI control, the phase-locking gain coefficient, and the angular velocity of the motor.

[0014] In a possible design, the upper controller is used to control the loop to determine the ripple voltage value of the motor according to the phase-locked angle and the sampling value, including:

[0015] The upper controller obtains the torque feedback value, the active current feedback value and the reactive current feedback value of the motor according to the phase-locked angle and the sampling value;

[0016] The upper controller performs PID control according to the torque feedback and the torque given value, and performs MTPA operation on the torque loop output obtained according to the output of the PID control and the current feedforward given value to obtain an active current given value and a reactive current given value;

[0017] The upper controller performs the PID control according to the active current given value and the active current feedback value to obtain a D-axis voltage given value, and obtains a D-axis output voltage value of the motor according to the D-axis voltage given value and a first feedforward voltage;

[0018] The upper controller performs the PID control according to the reactive current given value and the reactive current feedback value to obtain a Q-axis voltage given value, and obtains a Q-axis output voltage value of the motor according to the Q-axis voltage given value and a second feedforward voltage;

[0019] The upper controller performs coordinate system conversion on the D-axis voltage value and the Q-axis voltage value to obtain the wave-generating voltage value.

[0020] In a possible design, the acquisition frequency of the sampling values ​​and the control frequency are twice the carrier frequency of the motor.

[0021] In a possible design, the SVPWM wave generation method includes zero-crossing loading and peak loading within a switching cycle of the motor.

[0022] In one possible design, the motor includes a high-frequency permanent magnet motor.

[0023] In a second aspect, the present application provides a motor control device, which is applied to a control system of the motor, wherein the control system includes an upper controller and multiple lower controllers, and the upper controller is respectively connected to each lower controller for communication; the device includes:

[0024] A first control module, used for the upper controller to control the loop to determine the wave voltage value of the motor according to the control frequency, the phase-locked angle and the sampling value, and to obtain the wave voltage carrier comparison value according to the wave voltage value according to the SVPWM wave mode, wherein the control frequency and the acquisition frequency of the sampling value are multiples of the motor carrier frequency;

[0025] The second control module is used for the upper-level controller to synchronize the wave voltage carrier comparison value to each lower-level controller, and each lower-level controller uses the SVPWM wave generation method to generate wave according to a new wave voltage carrier comparison value obtained after conversion of the wave voltage carrier comparison value to control the torque of the motor.

[0026] In a possible design, a third control module is further included; the third control module is used to:

[0027] The upper controller acquires the sampled values ​​collected at the collection frequency, wherein the sampled values ​​include a sampled current and a sampled voltage;

[0028] The upper controller performs phase-locked control in a phase-locked loop by using a back-electromotive force recognition method, so as to obtain the phase-locked angle according to a phase-locked gain coefficient.

[0029] In a possible design, the third control module is further used to:

[0030] The upper controller performs PI control on the back electromotive force and the preset voltage deviation of the motor, and obtains the phase-locking angle of each beat of the motor according to the output of the PI control, the phase-locking gain coefficient, and the angular velocity of the motor.

[0031] In a possible design, the first control module is specifically used to:

[0032] The upper controller obtains the torque feedback value, the active current feedback value and the reactive current feedback value of the motor according to the phase-locked angle and the sampling value;

[0033] The upper controller performs PID control according to the torque feedback and the torque given value, and performs MTPA operation on the torque loop output obtained according to the output of the PID control and the current feedforward given value to obtain an active current given value and a reactive current given value;

[0034] The upper controller performs the PID control according to the active current given value and the active current feedback value to obtain a D-axis voltage given value, and obtains a D-axis output voltage value of the motor according to the D-axis voltage given value and a first feedforward voltage;

[0035] The upper controller performs the PID control according to the reactive current given value and the reactive current feedback value to obtain a Q-axis voltage given value, and obtains a Q-axis output voltage value of the motor according to the Q-axis voltage given value and a second feedforward voltage;

[0036] The upper controller performs coordinate system conversion on the D-axis voltage value and the Q-axis voltage value to obtain the wave-generating voltage value.

[0037] In a possible design, the acquisition frequency of the sampling values ​​and the control frequency are twice the carrier frequency of the motor.

[0038] In a possible design, the SVPWM wave generation method includes zero-crossing loading and peak loading within a switching cycle of the motor.

[0039] In a third aspect, the present application provides a control system for a motor, comprising: a processor, and a memory communicatively connected to the processor;

[0040] The memory stores computer-executable instructions;

[0041] The processor executes the computer-executable instructions stored in the memory to implement any possible motor control method provided in the first aspect.

[0042] In a fourth aspect, the present application provides a wind power generation device, comprising the control system of the motor provided in the third aspect, wherein the control system of the motor comprises an upper controller and a plurality of lower controllers, wherein the upper controller is respectively connected to each lower controller in communication;

[0043] The upper controller is used for the control loop to determine the wave voltage value of the motor according to the control frequency, the phase-locked angle and the sampling value, and obtain the wave voltage carrier comparison value according to the wave voltage value according to the SVPWM wave mode, and the control frequency and the acquisition frequency of the sampling value are multiples of the motor carrier frequency;

[0044] The upper controller synchronizes the wave voltage carrier comparison value to each lower controller, and each lower controller uses the SVPWM wave generation method to generate a new wave voltage carrier comparison value obtained after conversion of the wave voltage carrier comparison value to control the torque of the motor.

[0045] The present application provides a motor control method, device, system and wind power generation equipment, the motor control method is applied to the control system of the motor, the control system includes an upper controller and multiple lower controllers, and the upper controller is respectively connected to each lower controller in communication. First, the upper controller is used for the control loop to determine the wave voltage value of the motor according to the control frequency according to the phase-locked angle and the sampling value, and obtain the wave voltage carrier comparison value according to the SVPWM wave mode according to the wave voltage value, wherein the acquisition frequency of the sampling value and the control frequency of the upper controller are multiple times of the motor carrier frequency, and then the upper controller synchronizes the wave voltage carrier comparison value to each lower controller, and then each lower controller converts the wave voltage carrier comparison value, and uses the SVPWM wave mode to perform wave control according to the new wave voltage carrier comparison value obtained after conversion to control the torque of the motor. Combined with the sampling and control cycle of the system itself, the sampling frequency and the control frequency are increased to achieve the improvement of the response speed of the control system, which will not increase the switching loss while effectively improving the control bandwidth, and can effectively reduce the influence of the sampling and control delay caused by the original low switching frequency on the stability of the system, and ensure the stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0047] Figure 1 A schematic diagram of a system architecture of a motor control system provided in an embodiment of the present application;

[0048] Figure 2 A schematic diagram of a flow chart of a motor control method provided in an embodiment of the present application;

[0049] Figure 3A block diagram of a phase-locked loop for calculating a phase-locked angle provided in an embodiment of the present application;

[0050] Figure 4 A schematic diagram of a process for determining a wave voltage value through a control loop provided in an embodiment of the present application;

[0051] Figure 5 A control loop calculation block diagram provided in an embodiment of the present application;

[0052] Figure 6 A schematic diagram of a wave generation method provided in an embodiment of the present application;

[0053] Figures 7a to 7c A schematic diagram of test comparison waveforms provided in an embodiment of the present application;

[0054] Figure 8 A schematic diagram of the structure of a motor control device provided in an embodiment of the present application;

[0055] Fig. 9 A schematic diagram of the structure of another motor control device provided in an embodiment of the present application;

[0056] Fig.10 A schematic diagram of the structure of a motor control system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0057] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of methods and devices consistent with some aspects of the present application as detailed in the appended claims.

[0058] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0059] The related technology can achieve the effect of increasing the control bandwidth to a certain extent by increasing the carrier frequency, that is, increasing the sampling frequency, control frequency and carrier frequency. However, since the switching frequency is increased by increasing the carrier frequency, the switching loss will increase and the service life of the switch will be reduced. In addition, if the sampling frequency, control frequency and carrier frequency remain unchanged, and the control bandwidth is increased by modifying the control parameters and phase-locked loop control parameters, this solution can stably control the permanent magnet motor to a certain extent. However, as the speed, that is, the carrier frequency, continues to increase, the bandwidth improvement brought by parameter adjustment cannot fully meet the bandwidth requirements brought by the speed increase. Therefore, parameter adjustment cannot completely solve the problem.

[0060] In view of the above problems existing in the prior art, the present application provides a motor control method, device, system and wind power generation equipment. The inventive concept of the motor control method provided by the present application is: to increase the sampling frequency and the control frequency of the upper controller, and the upper controller acquires the motor's wave voltage value through the control loop combined with the phase-locked angle according to the sampling value collected at the increased sampling frequency and the increased control frequency, and obtains the wave voltage carrier comparison value according to the SVPWM (Space Vector Pulse Width Modulation) wave mode according to the wave voltage value. Then, the wave voltage carrier comparison value is synchronized to each lower controller connected to the upper controller. Each lower controller converts the synchronized wave voltage carrier comparison value, and then uses the SVPWM wave mode to perform wave control according to the new wave voltage carrier comparison value obtained after conversion to achieve torque control of the motor, wherein each lower controller is connected to the motor. Among them, the sampling frequency and control frequency are increased to multiple times of the carrier frequency, which can effectively reduce the impact of sampling and control delays caused by the original low switching frequency on the stability of the control system, and can effectively improve the control bandwidth of the system and improve the control stability of the system. It will not increase the switching loss and thus reduce the service life of the switch, so that the control system can achieve an ideal control effect.

[0061] Figure 1 A schematic diagram of the system architecture of a motor control system provided in an embodiment of the present application, such as Figure 1As shown, the control system 100 includes an upper controller 101 and multiple lower controllers, such as lower controller 102, lower controller 103 and lower controller 104. The upper controller 101 obtains the phase-locked angle by performing phase-locked control in the phase-locked loop according to the collected value, and the control loop determines the motor's wave voltage value according to the control frequency according to the phase-locked angle and the sampled value, and obtains the wave voltage carrier comparison value according to the SVPWM wave generation method according to the wave voltage value. The upper controller 101 synchronizes the wave voltage carrier comparison value to each lower controller, and each lower controller uses the SVPWM wave generation method to perform wave control according to the new wave voltage carrier comparison value obtained by converting the wave voltage carrier comparison value, so as to realize the torque control of the motor 200. Among them, each lower controller is connected to the motor 200 for communication.

[0062] It should be noted that the upper controller 100 and each lower controller include but are not limited to DSP (digital signal processor) chips and FPGA (Field-Programmable Gate Array), so that the upper controller 100 and each lower controller have signal processing capabilities. The upper controller 100 and each lower controller are connected in communication, for example, using optical fiber communication connection. The upper controller 100 and each lower controller use a one-to-many form to synchronize signals. For example, the upper controller 100 synchronizes the obtained waving voltage carrier comparison value to each lower controller by outputting a waving signal, so that each lower controller can synchronously perform waving control according to the new waving voltage carrier comparison value obtained by converting the waving voltage carrier comparison value to synchronously realize the torque control of the motor 200.

[0063] It is worth to understand that the motor 200 is only shown schematically and does not limit the number thereof.

[0064] Optionally, the motor 200 may be, for example, a high-frequency permanent magnet motor.

[0065] In some embodiments, the motor 200 may be applied to a wind power generation device.

[0066] It should be noted that the above system architecture is merely illustrative, and the motor control method, apparatus, device and storage medium provided by the embodiments of the present application include but are not limited to the above system architecture.

[0067] Figure 2 A flow chart of a motor control method provided in an embodiment of the present application, the motor control method can be applied to Figure 1 The control system shown in the figure includes an upper controller and multiple lower controllers, and the upper controller is connected to each lower controller for communication. Figure 2As shown, the motor control method provided by the embodiment of the present application includes:

[0068] S101: The upper-layer controller obtains sampling values ​​collected at a collection frequency.

[0069] The upper controller controls the acquisition component to acquire sampling values ​​according to the acquisition frequency. The sampling values ​​include the current current value and the current voltage value acquired on the motor side, that is, the acquired current and the acquired voltage. The upper controller obtains the acquired sampled voltage and sampled current.

[0070] The acquisition frequency may be a multiple of the carrier frequency, for example, the acquisition frequency may be at least twice the carrier frequency, such as f s =2f w , where f s is the sampling frequency of the control system, f w To control the carrier frequency of the system, the control system performs wave control according to the carrier frequency. It is worth noting that the acquisition frequency can also be other integer multiples of the carrier frequency.

[0071] In some embodiments, the collecting component may include an instrument for collecting sample values, such as a voltmeter, an ammeter, etc.

[0072] S102: The upper controller performs phase-locked control in the phase-locked loop by using a back-electromotive force recognition method to obtain a phase-locked angle according to a phase-locked gain coefficient.

[0073] The upper controller performs phase-locked control in the phase-locked loop through back-electromotive force recognition, and obtains the phase-locked angle of the motor for each beat according to the phase-locked gain system through phase-locked control.

[0074] Reference Figure 3 The phase-locked loop shown in the figure performs phase-locked control by back-EMF recognition. For example, the upper controller first performs PI control on the back-EMF Estd and the preset voltage deviation of the motor to obtain the output of the PI control, and then obtains the product of the output of the PI (Proportion Integration) control and the phase-locked gain coefficient K, and then integrates the product and the angular velocity W of the motor (as shown in FIG. Figure 3 The output of the phase-locked loop is the phase-locked angle θ of the motor for each beat, thus completing the phase-locked control process through the phase-locked loop. The phase-locked angle is used in the control loop to achieve stable control of the motor torque without increasing the actual switching frequency.

[0075] It can be understood that the phase-locked control process is the implementation method of obtaining the phase-locked angle by using the back-electromotive force recognition method in step S102. Figure 3 As shown in . The back electromotive force Estd of the motor is obtained by acquisition.

[0076] By obtaining the phase-locked angle through phase-locked control, compared with the prior art, the control bandwidth of the phase-locked control PI control (implemented by the PI regulator) can be improved within the control cycle, and the phase-locked control response speed can be effectively improved by increasing the adjustable gain coefficient K, thereby improving the control bandwidth of the phase-locked control and the recognition accuracy of each phase-locked angle. Optionally, the phase-locked gain coefficient K can be any integer from 1 to 10.

[0077] S103: The upper controller is used for the control loop to determine the wave voltage value of the motor according to the control frequency, the phase-locked angle and the sampling value.

[0078] The upper controller performs control loop calculation according to the control frequency, the phase-locked angle obtained by the phase-locked loop, and the sampled values ​​collected according to the sampling frequency through the control loop to determine the wave voltage value of the motor. The control frequency refers to the frequency at which the upper controller performs control loop calculation through the control loop. In the embodiment of the present application, the control frequency is a multiple of the motor carrier frequency, for example, the control frequency is at least twice the carrier frequency, such as the control frequency f c =2f w , where f c To control the frequency, f w It is worth noting that the control frequency can also be other integer multiples of the motor carrier frequency.

[0079] In a possible design, a possible implementation of step S103 is as follows: Figure 4 and Figure 5 As shown, Figure 4 A schematic diagram of a flow chart for determining a wave voltage value through a control loop provided in an embodiment of the present application, Figure 5 This is a control loop calculation block diagram provided in the embodiment of the present application. Figure 4 As shown, the embodiment of the present application includes:

[0080] S201: The upper controller obtains the torque feedback value, active current feedback value and reactive current feedback value of the motor according to the phase-locked angle and the sampling value.

[0081] The phase-locked angle calculated by the phase-locked loop and the sampled current in the sampled value are input to the control loop. The upper controller can calculate the torque feedback value T of the motor in the control loop. f , Active current feedback value I df , reactive current feedback value I qf (like Figure 5 As shown). Among them, the torque feedback value T f , Active current feedback value I df , reactive current feedback value I qfThe conventional calculation methods are not limited in the present application. For example, the active current feedback value I can be obtained by the following formula (1) when the sampling current and the phase-locking angle are known: df , reactive current feedback value I qf , and then the torque feedback value T is obtained through formulas (2)-(4) f .

[0082] I dqf =I abc *A (1)

[0083]

[0084]

[0085]

[0086] Among them, I abc Indicates the instantaneous value of the three-phase current, i.e., the current is used. A indicates the transformation matrix from the three-phase coordinate system to the DQ rotating coordinate system. Indicates the no-load magnetic field of the motor, L d Indicates the motor direct axis (D axis) inductance, L q Indicates the quadrature-axis (Q-axis) inductance of the motor.

[0087] S202: The upper controller performs PID (Proportion Integration Differentiation) control according to the torque feedback and the torque set value, and performs MTPA (Maximum Torque Per Ampere) operation on the torque loop output obtained according to the output of the PID control and the current feedforward set value to obtain the active current set value and the reactive current set value.

[0088] Reference Figure 5 As shown, the upper controller uses the control loop to feedback the torque T f and torque reference value T set The PID (Proportional Integral Derivative) control algorithm is used to perform PID control and obtain the PID control output. The output of the PID control plus the current feedforward given value is used to obtain the torque loop output. The torque loop output is processed by the MTPA (maximum torque / current ratio) algorithm to obtain the active current given value I dset and reactive current given value I qset Among them, the current feedforward given value is the ratio of the torque given value to the flux linkage, such as express.

[0089] S203a: The upper controller performs PID control according to the active current given value and the active current feedback value to obtain a D-axis voltage given value, and obtains a D-axis output voltage value of the motor according to the D-axis voltage given value and the first feedforward voltage.

[0090] Reference Figure 5 As shown, the upper controller uses the control loop to set the active current given value I df and active current feedback value I df After the PID control algorithm is used to perform PID control, the motor D-axis voltage set value is obtained. The D-axis voltage set value plus the first feedforward voltage U d Get the final D-axis output voltage value.

[0091] S203b: The upper controller performs PID control according to the reactive current given value and the reactive current feedback value to obtain a Q-axis voltage given value, and obtains a Q-axis output voltage value of the motor according to the Q-axis voltage given value and the second feedforward voltage.

[0092] Reference Figure 5 As shown, the upper controller uses the control loop to set the reactive current given value I qf and reactive current feedback value I qf After PID control is performed by the PID control algorithm, the motor Q-axis voltage set value is obtained. The Q-axis voltage set value plus the second feedforward voltage U q Get the final Q-axis output voltage value.

[0093] Among them, the sampled voltage in the sampled value includes the first feedforward voltage U d and the second feedforward voltage U q .

[0094] S204: The upper controller performs coordinate system conversion on the D-axis voltage value and the Q-axis voltage value to obtain a wave-generating voltage value.

[0095] Reference Figure 5 As shown, the upper controller transforms the D-axis voltage value and the Q-axis voltage value in the control loop from the rotating coordinate system to the stationary coordinate system, and then the αβ wave voltage value can be obtained, and the αβ wave voltage value is defined as the wave voltage value.

[0096] So far, through Figure 4 In the steps shown, the upper controller completes the control operation through the control loop according to the control frequency to obtain the wave voltage value. The control operation process is as follows Figure 5 shown.

[0097] S104: The upper controller obtains a wave voltage carrier comparison value according to the wave voltage value in accordance with the SVPWM wave generation method.

[0098] The SVPWM wave generation method can include zero-crossing loading and peak loading, that is, zero-crossing loading and peak loading are used when configuring the carrier loading. The wave generation voltage value calculated by the control loop is used as the input of SVPWM, and the output of SVPWM obtained under the SVPWM wave generation control is the wave generation voltage carrier comparison value. Among them, the wave generation voltage carrier comparison value obtained according to the SVPWM wave generation method is to use the wave generation voltage value as the input of SVPWM to obtain the SVPWM output when zero-crossing loading and peak loading are performed, such as Figure 5 shown.

[0099] S105: The upper-layer controller synchronously sends a voltage carrier comparison value to each lower-layer controller.

[0100] The upper controller increases the sampling frequency and control frequency to obtain the wave voltage value, which can effectively increase the control bandwidth. Since the carrier frequency remains unchanged, the switching loss is not actually increased. The upper controller calculates the wave voltage value according to the SVPWM wave mode to obtain the wave voltage carrier comparison value, and then synchronizes the wave voltage carrier comparison value to each lower controller connected to it, so that the lower controller performs wave control.

[0101] S106: Each lower-layer controller uses SVPWM wave generation to generate wave according to a new wave voltage carrier comparison value obtained after conversion of the wave voltage carrier comparison value to control the torque of the motor.

[0102] Since the control frequency is a multiple of the carrier frequency, for example, twice, the wave value generated by the control algorithm, i.e., the wave voltage value, is calculated based on the control frequency, and accordingly, the wave voltage carrier comparison value obtained based on the wave voltage value is also obtained based on the control frequency. When each lower-level controller synchronizes to the wave voltage carrier comparison value and performs wave control based on it, it is necessary to convert the synchronized wave voltage carrier comparison value according to the following formula (5) to obtain a new wave voltage carrier comparison value, and perform wave control based on the converted new wave voltage carrier comparison value.

[0103] PWM CompareValue =PWM ctrl *Num (5)

[0104] Among them, PWM in formula (5) CompareValue Indicates the new wave voltage carrier comparison value obtained after the final wave value is converted, PWM ctrl It indicates the comparison value of the carrier wave voltage before conversion. Num indicates the ratio of the control frequency to the carrier frequency, that is, Num = f c / f w .

[0105] In a possible design, each lower-level controller converts the synchronized wave voltage carrier comparison value according to formula (5), and then uses SVPWM wave generation to generate wave according to the new wave voltage carrier comparison value obtained after conversion to achieve torque control of the motor.

[0106] Among them, the SVPWM wave generation mode includes zero-crossing loading and peak loading, that is, zero-crossing loading and peak loading are used when configuring carrier loading. For example, if the control frequency is twice the carrier frequency, the SVPWM wave generation mode can be as follows Figure 6 As shown, zero loading and peak loading are performed within one switching cycle of the motor, which is equivalent to loading twice within one switching cycle, indirectly increasing the carrier frequency, that is, the wave transmission frequency, and achieving double update of the wave transmission, but actually does not increase the switching loss, thereby coping with the oscillation problem caused by the low control bandwidth caused by the sampling and control speed.

[0107] It can be seen from the above-mentioned embodiments that the motor control method provided by the embodiments of the present application can improve the control bandwidth of the phase-locked control PI within the control cycle, and can effectively improve the phase-locked control adjustment speed by increasing the adjustable gain coefficient K, thereby improving the control bandwidth of the phase-locked control and improving the phase-locked angle recognition accuracy of each beat of the phase-locked loop. On the basis of obtaining the phase-locked angle through phase-locked control, increasing the sampling frequency and the control frequency can effectively reduce the influence of the sampling and control delays caused by the low original switching frequency on the stability of the control system, thereby effectively improving the control bandwidth of the control system and improving the stability of the control system.

[0108] From the perspective of improving the response time of the control system and enhancing stability, the sampling and control frequencies of the control system are required to be as high as possible. However, due to the execution time of the control system and the execution speed of the processor, the sampling and control speeds are limited. Compared with the related art, the embodiments of the present application combine the sampling and control cycles of the control system itself, and improve the system response speed by increasing the sampling frequency and the control frequency. Figures 7a to 7c The test results shown also verify that the stability of the system can be improved.

[0109] Figures 7a to 7c A schematic diagram of test comparison waveforms provided in an embodiment of the present application, wherein: Figure 7a The current waveform obtained by debugging the high-frequency permanent magnet motor using the conventional method of related technology, Figure 7b A current waveform obtained by debugging a high-frequency permanent magnet motor using the motor control method provided by the present application, Figure 7c for Figure 7bIn the test, the carrier frequency is 2000Hz, the sampling frequency and the control frequency are 4000Hz. The motor control method provided in the embodiment of the present application can increase the upper limit of the frequency of the motor torque stability control from 80Hz to about 140Hz. Figure 7a and Figure 7b visible, Figure 7a If the motor control method provided in this application is not adopted, the waveform will have jitter, that is, the system stability is poor. Figure 7b After adopting the motor control method provided by this application, the waveform is smooth and there is no jitter ( Figure 7b The local enlarged view is shown in 7c). From the waveform obtained by the test, it can be seen that the motor can run stably.

[0110] Furthermore, through the sampling delay calculation formula shown in the following formula (6), it can be known that as the angle delay becomes smaller and smaller, the impact of the angle delay on the system stability will also become smaller and smaller.

[0111] θ T =kwΔT=k*2πf n *ΔT=k*2πf n / f s (6)

[0112] Where k is the angle gain coefficient, f n Indicates the actual speed frequency of the motor, f s Indicates the sampling frequency.

[0113] From the above formula, it can be concluded that as the sampling frequency f s If the angle is increased, the angle delay θ T It will become smaller and smaller, which means that the angle delay has less and less impact on the system stability.

[0114] Figure 8 The present invention provides a schematic diagram of the structure of a motor control device, which can be applied to a motor control system. The control system includes an upper controller and multiple lower controllers, and the upper controller is connected to each lower controller in communication. Figure 8 As shown, the motor control device 400 provided in the embodiment of the present application includes:

[0115] The first control module 401 is used for the upper controller to control the loop to determine the motor's wave voltage value according to the control frequency, the phase-locked angle and the sampling value, and obtain the wave voltage carrier comparison value according to the SVPWM wave mode according to the wave voltage value, and the control frequency and the sampling value acquisition frequency are multiples of the motor carrier frequency;

[0116] The second control module 402 is used for the upper controller to synchronize the voltage carrier comparison value to each lower controller, and each lower controller uses SVPWM to generate voltage carrier comparison value to control the torque of the motor according to the new voltage carrier comparison value converted from the voltage carrier comparison value.

[0117] exist Figure 8 On the basis of Fig. 9 This is a schematic diagram of the structure of another motor control device provided in an embodiment of the present application. Fig. 9 As shown, the motor control device 400 provided in the embodiment of the present application further includes a third control module 403, and the third control module 403 is used to:

[0118] The upper controller obtains the sampled values ​​collected at the collection frequency, and the sampled values ​​include the sampled current and the sampled voltage;

[0119] The upper controller uses a back-electromotive force recognition method in the phase-locked loop to perform phase-locked control to obtain the phase-locked angle according to the phase-locked gain coefficient.

[0120] In a possible design, the third control module 403 is further configured to:

[0121] The upper controller performs PI control on the back electromotive force and the preset voltage deviation of the motor, and obtains the phase-locking angle of the motor for each beat according to the output of the PI control, the phase-locking gain coefficient and the angular velocity of the motor.

[0122] In a possible design, the first control module 401 is specifically configured to:

[0123] The upper controller obtains the torque feedback value, active current feedback value and reactive current feedback value of the motor according to the phase-locked angle and the sampling value;

[0124] The upper controller performs PID control according to the torque feedback and the torque given value, and performs MTPA operation on the torque loop output obtained according to the output of the PID control and the current feedforward given value to obtain the active current given value and the reactive current given value;

[0125] The upper controller performs PID control according to the active current given value and the active current feedback value to obtain the D-axis voltage given value, and obtains the D-axis output voltage value of the motor according to the D-axis voltage given value and the first feedforward voltage;

[0126] The upper controller performs PID control according to the reactive current given value and the reactive current feedback value to obtain the Q-axis voltage given value, and obtains the Q-axis output voltage value of the motor according to the Q-axis voltage given value and the second feedforward voltage;

[0127] The upper controller performs coordinate system conversion on the D-axis voltage value and the Q-axis voltage value to obtain the wave voltage value.

[0128] In a possible design, the acquisition frequency and control frequency of the sampled values ​​are twice the motor carrier frequency.

[0129] In one possible design, the SVPWM wave generation method includes zero-crossing loading and peak loading within one switching cycle of the motor.

[0130] The motor control device provided in the embodiment of the present application can execute each step of the motor control method in the above method embodiment. Its implementation principle and technical effect are similar and will not be repeated here.

[0131] Fig.10 This is a schematic diagram of the structure of a motor control system provided in an embodiment of the present application. Fig.10 As shown, the control system 500 may include: a processor 501 , and a memory 502 communicatively connected to the processor 501 .

[0132] The memory 502 is used to store programs. Specifically, the programs may include program codes, and the program codes include computer-executable instructions.

[0133] The memory 502 may include a high-speed RAM memory, and may also include a non-volatile memory (NoN-volatile memory), such as at least one disk memory.

[0134] The processor 501 is used to execute the computer-executable instructions stored in the memory 502 to implement the motor control method.

[0135] The processor 501 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0136] Optionally, the memory 502 may be independent or integrated with the processor 501. When the memory 502 is a device independent of the processor 501, the control system 500 may further include:

[0137] The bus 503 is used to connect the processor 501 and the memory 502. The bus can be an industry standard architecture (ISA) bus, a peripheral component interconnect (PCI) bus, or an extended industry standard architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc., but it does not mean that there is only one bus or one type of bus.

[0138] Optionally, in a specific implementation, if the memory 502 and the processor 501 are integrated on a chip, the memory 502 and the processor 501 can communicate through an internal interface.

[0139] The embodiment of the present application further provides a wind power generation device, which includes the control system of the motor provided in the above embodiment, the control system of the motor includes an upper controller and multiple lower controllers, and the upper controller is respectively connected to each lower controller for communication;

[0140] The upper controller is used for the control loop to determine the motor's wave voltage value according to the control frequency, the phase-locked angle and the sampling value, and obtain the wave voltage carrier comparison value according to the SVPWM wave mode. The control frequency and the sampling value acquisition frequency are multiples of the motor carrier frequency.

[0141] The upper controller synchronously transmits the voltage carrier comparison value to each lower controller, and each lower controller uses SVPWM to transmit the new voltage carrier comparison value obtained after conversion to control the torque of the motor.

[0142] The present application also provides a computer-readable storage medium, which may include: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, and other media that can store program codes. Specifically, the computer-readable storage medium stores computer execution instructions, and the computer execution instructions are used for each step of the method in the above embodiment.

[0143] The present application also provides a computer program product, including computer execution instructions, which implement the steps of the method in the above embodiment when executed by a processor.

[0144] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the claims.

[0145] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A motor control method, characterized in that: A control system applied to the motor, the control system comprising an upper controller and a plurality of lower controllers, the upper controller being respectively connected to each lower controller in communication; the method comprising: The upper controller is used for the control loop to determine the wave voltage value of the motor according to the control frequency, the phase-locked angle and the sampling value, and obtain the wave voltage carrier comparison value according to the wave voltage value according to the SVPWM wave mode, and the control frequency and the acquisition frequency of the sampling value are multiples of the motor carrier frequency; The upper controller synchronizes the wave voltage carrier comparison value to each lower controller, and each lower controller uses the SVPWM wave generation method to generate a new wave voltage carrier comparison value obtained after conversion of the wave voltage carrier comparison value to control the torque of the motor.

2. The motor control method according to claim 1, characterized in that: Before the upper controller is used to control the loop to determine the wave voltage value of the motor according to the control frequency according to the phase-locked angle and the sampling value, it also includes: The upper controller acquires the sampled values ​​collected at the collection frequency, wherein the sampled values ​​include a sampled current and a sampled voltage; The upper controller performs phase-locked control in a phase-locked loop by using a back-electromotive force recognition method, so as to obtain the phase-locked angle according to a phase-locked gain coefficient.

3. The motor control method according to claim 2, characterized in that: The upper controller uses the back-electromotive force identification method to perform phase-locked control in the phase-locked loop to obtain the phase-locked angle according to the phase-locked gain coefficient, including: The upper controller performs PI control on the back electromotive force and the preset voltage deviation of the motor, and obtains the phase-locking angle of each beat of the motor according to the output of the PI control, the phase-locking gain coefficient, and the angular velocity of the motor.

4. The motor control method according to any one of claims 1 to 3, characterized in that: The upper controller is used for the control loop to determine the wave voltage value of the motor according to the phase-locked angle and the sampling value, including: The upper controller obtains the torque feedback value, the active current feedback value and the reactive current feedback value of the motor according to the phase-locked angle and the sampling value; The upper controller performs PID control according to the torque feedback and the torque given value, and performs MTPA operation on the torque loop output obtained according to the output of the PID control and the current feedforward given value to obtain an active current given value and a reactive current given value; The upper controller performs the PID control according to the active current given value and the active current feedback value to obtain a D-axis voltage given value, and obtains a D-axis output voltage value of the motor according to the D-axis voltage given value and a first feedforward voltage; The upper controller performs the PID control according to the reactive current given value and the reactive current feedback value to obtain a Q-axis voltage given value, and obtains a Q-axis output voltage value of the motor according to the Q-axis voltage given value and a second feedforward voltage; The upper controller performs coordinate system conversion on the D-axis voltage value and the Q-axis voltage value to obtain the wave-generating voltage value.

5. The motor control method according to claim 4, characterized in that: The sampling value acquisition frequency and the control frequency are twice the motor carrier frequency.

6. The motor control method according to claim 5, characterized in that: The SVPWM wave generation method includes performing zero-crossing loading and peak loading within a switching cycle of the motor.

7. The motor control method according to claim 1, characterized in that: The motor comprises a high frequency permanent magnet motor.

8. A motor control device, characterized in that: A control system applied to the motor, the control system comprising an upper controller and a plurality of lower controllers, the upper controller being respectively connected to each lower controller in communication; the device comprising: A first control module, used for the upper controller to control the loop to determine the wave voltage value of the motor according to the control frequency, the phase-locked angle and the sampling value, and to obtain the wave voltage carrier comparison value according to the wave voltage value according to the SVPWM wave mode, wherein the control frequency and the acquisition frequency of the sampling value are multiples of the motor carrier frequency; The second control module is used for the upper-level controller to synchronize the wave voltage carrier comparison value to each lower-level controller, and each lower-level controller uses the SVPWM wave generation method to generate wave according to a new wave voltage carrier comparison value obtained after conversion of the wave voltage carrier comparison value to control the torque of the motor.

9. The motor control device according to claim 8, characterized in that: The third control module is further included; the third control module is used to: The upper controller acquires the sampled values ​​collected at the collection frequency, wherein the sampled values ​​include a sampled current and a sampled voltage; The upper controller performs phase-locked control in a phase-locked loop by using a back-electromotive force recognition method, so as to obtain the phase-locked angle according to a phase-locked gain coefficient.

10. The motor control device according to claim 9, characterized in that: The third control module is further used for: The upper controller performs PI control on the back electromotive force and the preset voltage deviation of the motor, and obtains the phase-locking angle of each beat of the motor according to the output of the PI control, the phase-locking gain coefficient, and the angular velocity of the motor.

11. The motor control device according to any one of claims 8 to 10, characterized in that: The first control module is specifically used to: The upper controller obtains the torque feedback value, the active current feedback value and the reactive current feedback value of the motor according to the phase-locked angle and the sampling value; The upper controller performs PID control according to the torque feedback and the torque given value, and performs MTPA operation on the torque loop output obtained according to the output of the PID control and the current feedforward given value to obtain an active current given value and a reactive current given value; The upper controller performs the PID control according to the active current given value and the active current feedback value to obtain a D-axis voltage given value, and obtains a D-axis output voltage value of the motor according to the D-axis voltage given value and a first feedforward voltage; The upper controller performs the PID control according to the reactive current given value and the reactive current feedback value to obtain a Q-axis voltage given value, and obtains a Q-axis output voltage value of the motor according to the Q-axis voltage given value and a second feedforward voltage; The upper controller performs coordinate system conversion on the D-axis voltage value and the Q-axis voltage value to obtain the wave-generating voltage value.

12. The motor control device according to claim 11, characterized in that: The sampling value acquisition frequency and the control frequency are twice the motor carrier frequency.

13. The motor control device according to claim 12, characterized in that: The SVPWM wave generation method includes performing zero-crossing loading and peak loading within a switching cycle of the motor.

14. A control system for a motor, characterized in that: include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the motor control method according to any one of claims 1 to 7.

15. A wind power generation device, characterized in that: A control system for a motor comprising the motor of claim 14, wherein the control system for the motor comprises an upper controller and a plurality of lower controllers, wherein the upper controller is respectively connected to each lower controller for communication; The upper controller is used for the control loop to determine the wave voltage value of the motor according to the control frequency, the phase-locked angle and the sampling value, and obtain the wave voltage carrier comparison value according to the wave voltage value according to the SVPWM wave mode, and the control frequency and the acquisition frequency of the sampling value are multiples of the motor carrier frequency; The upper controller synchronizes the wave voltage carrier comparison value to each lower controller, and each lower controller uses the SVPWM wave generation method to generate a new wave voltage carrier comparison value obtained after conversion of the wave voltage carrier comparison value to control the torque of the motor.

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