A method, device, and motor for controlling an electric motor

Abstract

This invention discloses a motor control method, apparatus, and motor. The motor control method includes: acquiring the voltage and current of the motor during operation; determining the observed back EMF of the motor based on the voltage and current, and performing multiple iterations on the observed back EMF; processing the observed back EMF after multiple iterations using a phase-locked loop to obtain the observed angle and angular velocity of the motor, so as to perform positionless control of the motor. The motor control method, apparatus, and motor provided by this invention can improve the reliability and stability of motor control.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to motor control technology, and particularly relate to a motor control method and device and motor. BACKGROUND

[0002] As a device for converting electrical energy into mechanical energy, a motor is widely used in various industrial fields. The motor needs to be reliably controlled during operation to ensure normal operation of the motor. At present, the existing motor control method usually uses a sliding mode observation method to control the motor without position. However, the control reliability of this method needs to be improved. SUMMARY

[0003] Embodiments of the present application provide a motor control method, device and motor to improve the reliability and stability of motor control.

[0004] In a first aspect, embodiments of the present application provide a motor control method, comprising:

[0005] obtaining a voltage and a current of the motor during operation;

[0006] determining an observed back electromotive force of the motor based on the voltage and the current, and performing multiple iterations on the observed back electromotive force;

[0007] performing phase-locked loop processing on the observed back electromotive force after the multiple iterations to obtain an observed angle and an observed angular velocity of the motor, so as to control the motor without position.

[0008] Optionally, the phase-locked loop processing on the observed back electromotive force is performed once when the observed back electromotive force is iterated N times; the refresh frequency of the iteration process of the observed back electromotive force is a first refresh frequency, and the refresh frequency of the phase-locked loop processing is a second refresh frequency, the first refresh frequency is N times of the second refresh frequency, and N is greater than or equal to 10.

[0009] Optionally, the first refresh frequency is 100 kHz, and the second refresh frequency is 10 kHz.

[0010] Optionally, the multiple iterations on the observed back electromotive force comprise:

[0011] calculating a current corresponding to the observed back electromotive force according to the observed back electromotive force;

[0012] when the current corresponding to the observed back electromotive force is greater than or less than the current of the motor during operation, adjusting the size of the observed back electromotive force to obtain a new observed back electromotive force.

[0013] Optionally, the multiple iterations on the observed back electromotive force comprise:

[0014] The observed back potential is iterated a preset number of times, wherein the preset number of times is greater than or equal to 10.

[0015] Optionally, determining the observed back EMF of the motor based on the voltage and current, and iterating the observed back EMF multiple times, includes:

[0016] Based on the voltage and current, the observed back EMF of the motor is determined using a sliding mode control algorithm for the motor.

[0017] Based on the sliding mode control algorithm, the observed back EMF is iterated multiple times, and each iteration of the observed back EMF corresponds to a filtering process.

[0018] Optionally, when the filtering process is executed N times, the phase-locked loop process is executed once, where N is greater than or equal to 10.

[0019] In a second aspect, embodiments of the present invention provide a motor control device, comprising:

[0020] The parameter acquisition module is used to acquire the voltage and current of the motor during operation;

[0021] An iterative module is used to determine the observed back EMF of the motor based on the voltage and current, and to perform multiple iterations on the observed back EMF;

[0022] The motor control module is used to process the observed back EMF after multiple iterations using a phase-locked loop to obtain the observed angle and angular velocity of the motor, so as to perform positionless control of the motor.

[0023] Thirdly, embodiments of the present invention provide an electric motor, which is controlled by the control method described in the first aspect.

[0024] Optionally, the motor is a permanent magnet synchronous motor.

[0025] The present invention provides a motor control method, apparatus, and motor. The motor control method includes: acquiring the voltage and current of the motor during operation; determining the observed back EMF of the motor based on the voltage and current, and iterating the observed back EMF multiple times; and performing phase-locked loop (PLL) processing on the observed back EMF after multiple iterations to obtain the observed angle and angular velocity of the motor for positionless control. The motor control method, apparatus, and motor provided by the present invention, by iterating the observed back EMF determined based on voltage and current multiple times and performing PLL processing on the observed back EMF after multiple iterations to obtain the observed angle and angular velocity of the motor for positionless control, wherein the observed back EMF is iterated multiple times (e.g., ten times) and the PLL processing is performed once, the reliability of the obtained observed back EMF data is high, thereby improving the reliability of the obtained observed angle and angular velocity data of the motor, and thus improving the reliability and stability of motor control. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of current in existing technology;

[0027] Figure 2 This is a schematic diagram of current following in existing technology;

[0028] Figure 3 This is a schematic diagram of the back electromotive force in the prior art;

[0029] Figure 4 This is a flowchart of a motor control method provided in Embodiment 1 of the present invention;

[0030] Figure 5 This is a schematic diagram of an electric current provided in Embodiment 1 of the present invention;

[0031] Figure 6 This is a flowchart of a motor control method provided in Embodiment 2 of the present invention;

[0032] Figure 7 This is a schematic diagram of a sliding mode observation and phase-locked loop provided in Embodiment 2 of the present invention;

[0033] Figure 8 This is a schematic diagram of a motor without position control provided in Embodiment 2 of the present invention;

[0034] Figure 9 This is a schematic diagram of a phase-locked loop provided in Embodiment 2 of the present invention;

[0035] Figure 10 This is a schematic diagram of a current follower provided in Embodiment 2 of the present invention;

[0036] Figure 11 This is a schematic diagram of a back potential provided in Embodiment 2 of the present invention;

[0037] Figure 12 This is a structural block diagram of a motor control device provided in Embodiment 3 of the present invention;

[0038] Figure 13 This is a schematic diagram of the structure of an electronic device provided in Embodiment 4 of the present invention. Detailed Implementation

[0039] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0040] Figure 1 This is a schematic diagram of current in existing technology. Figure 2 This is a schematic diagram of current following in existing technology. Figure 3 This is a schematic diagram of the back potential in existing technology. (Reference) Figures 1-3 , Figure 1 The black line in the middle corresponds to the actual discrete current of the motor. Figure 1 The red line in the middle corresponds to the current observed by traditional sliding mode. The difference between the current observed by traditional sliding mode and the actual discrete current of the motor is relatively large. Figure 2 The waveform shown by the blue line is the actual current waveform of the motor, which is a sine wave. Figure 2 The waveform shown by the red line is a current waveform based on traditional sliding mode observation. This current waveform has large ripple and poor current tracking performance. Figure 3 The waveform shown by the yellow line is the actual voltage waveform of the motor, and the waveform shown by the green line is the back EMF waveform based on traditional sliding mode observation. The back EMF waveform has DC drift and large ripple.

[0041] Example 1

[0042] Figure 4 This is a flowchart of a motor control method provided in Embodiment 1 of the present invention. This embodiment is applicable to motor control, such as non-position control, etc. The method can be executed by a motor control device, which can be integrated into an electronic device such as a computer. The control device can be implemented in software and / or hardware. The method specifically includes the following steps:

[0043] Step 110: Obtain the voltage and current of the motor during operation.

[0044] The voltage and current can be the three-phase voltage and three-phase current output in real time when the motor, such as a permanent magnet synchronous motor, is running. The motor's control device is electrically connected to the motor to obtain the voltage and current during motor operation in real time.

[0045] Step 120: Based on voltage and current, determine the observed back EMF of the motor and perform multiple iterations on the observed back EMF.

[0046] Specifically, taking the three-phase voltage and three-phase current output in real time during motor operation as an example, the three-phase voltage and three-phase current are converted into two-phase voltage and two-phase current in a static coordinate system. Based on the relationship between the two-phase voltage and two-phase current in the static coordinate system and the actual back EMF of the motor, as well as the sliding mode observation algorithm, the observed back EMF of the motor is determined, and the observed back EMF is iterated multiple times, with the observed back EMF being filtered once in each iteration.

[0047] Step 130: Process the observed back EMF after multiple iterations using a phase-locked loop to obtain the observed angle and angular velocity of the motor, so as to perform positionless control of the motor.

[0048] Specifically, each phase-locked loop (PLL) process corresponds to multiple iterations of the observed back EMF to ensure the accuracy of the observed back EMF data. The observed back EMF after multiple iterations is then processed by the PLL to obtain the observed angle and angular velocity of the motor. Based on the observed angle and angular velocity, the motor's position can be determined, thus achieving positionless control of the motor.

[0049] Figure 5 This is a schematic diagram of an electric current provided in Embodiment 1 of the present invention. (Reference) Figure 5 , Figure 5 The black line in the middle corresponds to the actual discrete current of the motor. Figure 5 The red line in the middle corresponds to the current observed by sliding mode in this embodiment, compared with the prior art. Figure 1 This embodiment Figure 5 The difference between the current observed in the sliding mode and the actual discrete current of the motor is relatively small.

[0050] It should be noted that the specific number of power levels and the specific duration of operation in this embodiment can be determined according to the actual control requirements of the motor, and are not limited here.

[0051] The motor control method provided in this embodiment includes: acquiring the voltage and current of the motor during operation; determining the observed back EMF of the motor based on the voltage and current, and iterating the observed back EMF multiple times; processing the observed back EMF after multiple iterations using a phase-locked loop to obtain the observed angle and angular velocity of the motor, so as to perform positionless control of the motor. The motor control method provided in this embodiment, by iterating the observed back EMF determined based on voltage and current multiple times, and processing the observed back EMF after multiple iterations using a phase-locked loop to obtain the observed angle and angular velocity of the motor, can perform positionless control of the motor. The multiple iterations of the observed back EMF (e.g., ten times) and the single phase-locked loop processing result in higher reliability of the obtained observed back EMF data, thereby improving the reliability of the obtained observed angle and angular velocity data of the motor, and ultimately improving the reliability and stability of the motor control.

[0052] Example 2

[0053] Figure 6 This is a flowchart of a motor control method provided in Embodiment 2 of the present invention. This embodiment is applicable to motor control, such as non-position control, etc. The method can be executed by a motor control device, which can be integrated into an electronic device such as a computer. The control device can be implemented in software and / or hardware. The method specifically includes the following steps:

[0054] Step 210: Obtain the voltage and current of the motor during operation.

[0055] The voltage and current can be the three-phase voltage and three-phase current output in real time when the motor, such as a permanent magnet synchronous motor, is running. The motor's control device is electrically connected to the motor to obtain the voltage and current during motor operation in real time.

[0056] Step 220: Based on the voltage and current, determine the observed back EMF of the motor using the sliding mode control algorithm of the motor.

[0057] Specifically, taking the three-phase voltage and three-phase current, which are the real-time outputs of the motor during operation, as an example, the three-phase voltage and three-phase current are converted into voltage u in a two-phase stationary coordinate system. α u β and current i α i β Based on the voltage and current in the two-phase stationary coordinate system and the actual back electromotive force E of the motor α E β The relationship between voltage u and the observed back EMF of the motor is determined. Taking a surface-mounted permanent magnet synchronous motor as an example, in a two-phase stationary coordinate system, the voltage u... α u β and current i α i β With the actual back potential E α Eβ The relational equation is: , where R s L is the stator resistance of the motor. d Let be the stator inductance of the motor. Based on the above equations, an observation model can be constructed, and the equations of the observation model are: ,in, The observed current along the α-axis in a two-phase stationary coordinate system. Let v be the observed current along the β-axis in a two-phase stationary coordinate system. α v β Let be the control variables of the model. Subtracting the two equations above, we obtain the current error equation: ,in, , , representing the current observation error. The sliding mode control law is: , where k is a coefficient, a known quantity, and sgn() is a sign function, temporarily treating the model's control variables as the observed back electromotive force.

[0058] Step 230: Based on the motor sliding mode control algorithm, calculate the current corresponding to the observed back EMF according to the observed back EMF.

[0059] The current corresponding to the observed back electromotive force is the observed current mentioned above, which is determined by the model's control variable v. α v β The observed current can be deduced from this.

[0060] Step 240: When the current corresponding to the observed back EMF is greater than or less than the current when the motor is running, adjust the magnitude of the observed back EMF accordingly to obtain a new observed back EMF, and then iterate the observed back EMF a preset number of times.

[0061] The preset number of iterations is greater than or equal to 10. Specifically, when the current corresponding to the observed back EMF is greater than or less than the current during motor operation, the magnitude of the observed back EMF is adjusted accordingly to obtain a new observed back EMF, and the current corresponding to the new observed back EMF is calculated. When the current corresponding to the new observed back EMF is greater than or less than the current during motor operation, the magnitude of the new observed back EMF is adjusted accordingly to obtain an updated observed back EMF. This process of updating and iterating the observed back EMF for a preset number of times, such as 10, is repeated. The adjustment of the observed back EMF can be achieved by adjusting the control variable v. α v β To achieve this, when the control variable reaches the sliding surface... =0, After =0, it will remain on the sliding surface. At this time, the control variable can be regarded as the equivalent control variable based on the equivalent control principle in sliding mode control, and we can obtain: Where eq represents equivalence, and the control variable v α vβ It contains a high-frequency dithering array, which requires low-pass filtering to obtain the observed back EMF. and Each iteration of the back EMF observation corresponds to one filtering process. Furthermore, the current differentiation and integration operations can use a variable time interval obtained from a high-frequency timer as the integration step size to adapt to the requirements of high refresh rate operation.

[0062] Step 250: Perform phase-locked loop processing on the observed back EMF that has completed a preset number of iterations to obtain the observed angle and angular velocity of the motor.

[0063] Specifically, when the back EMF is observed iterated N times (including N filtering iterations), the phase-locked loop (PLL) processing for back EMF observation is executed once. The refresh frequency of the back EMF observation iteration process is the first refresh frequency, the refresh frequency of the filtering process is also the first refresh frequency, and the refresh frequency of the PLL processing is the second refresh frequency. The first refresh frequency is N times the second refresh frequency, where N is greater than or equal to 10. For example, N is 10, the first refresh frequency is 100 kHz, and the second refresh frequency is 10 kHz. For instance, at a refresh frequency of 10 kHz, the available runtime for the program is 100 μs, while the actual runtime may be 20-30 μs, providing ample time for other calculations. Therefore, the refresh frequency for back EMF observation and low-pass filtering can be increased to 10 times that of the PLL, meaning that the PLL processing for back EMF observation is executed once when the back EMF is observed iterated N times (including N filtering iterations).

[0064] Figure 7 This is a schematic diagram of a sliding mode observation and phase-locked loop provided in Embodiment 2 of the present invention. Figure 8 This is a schematic diagram of a motor without position control provided in Embodiment 2 of the present invention. Figure 9 This is a schematic diagram of a phase-locked loop provided in Embodiment 2 of the present invention. (Reference) Figures 7-9 The motor's positionless control employs a sliding mode positionless control strategy, which includes proportional-integral (PI) control, coordinate transformations such as Clarke transform, Park transform, and inverse Park transform, and parameter k during phase-locked loop processing. p k i The observation angle of the motor can be obtained using the functions s, cos, and sin. and observed angular velocity The specific process can be found in existing technologies and will not be elaborated here.

[0065] Figure 10 This is a schematic diagram of a current follower provided in Embodiment 2 of the present invention. Figure 11 This is a schematic diagram of a back potential provided in Embodiment 2 of the present invention. (Reference) Figure 10 and Figure 11 , Figure 10The waveform shown by the blue line is the actual current waveform of the motor, which is a sine wave. Figure 10 The waveform shown by the red line is the observed current waveform based on this embodiment. The two waveforms are basically overlapping, which is different from the existing technology. Figure 2 In this embodiment Figure 10 The current following effect is relatively good. Figure 11 The waveform shown by the yellow line is the actual voltage waveform of the motor, and the waveform shown by the green line is the observed back EMF waveform in this embodiment. Compared with the prior art... Figure 3 In this embodiment Figure 11 The observed back EMF waveform has good sinusoidal properties, no DC drift, and small ripple.

[0066] It should be noted that the values ​​of each parameter in this embodiment are only for illustrative purposes and can be determined according to the actual control requirements of the motor, and are not limited here.

[0067] The motor control method provided in this embodiment includes: acquiring the voltage and current of the motor during operation; determining the observed back EMF of the motor based on the voltage and current and a sliding mode control algorithm of the motor; calculating the current corresponding to the observed back EMF based on the observed back EMF using the sliding mode control algorithm of the motor; adjusting the magnitude of the observed back EMF when the current corresponding to the observed back EMF is greater than or less than the current during motor operation to obtain a new observed back EMF, and iterating the observed back EMF a preset number of times; and performing phase-locked loop processing on the observed back EMF that has completed the preset number of iterations to obtain the observed angle and angular velocity of the motor. The motor control method provided in this embodiment iterates the observed back EMF determined based on voltage and current for a preset number of times, such as ten times, and then processes the observed back EMF after the preset number of iterations using a phase-locked loop (PLL) to obtain the observed angle and angular velocity of the motor for positionless control. The preset number of back EMF iterations includes a preset number of filtering processes (e.g., ten times) and one PLL process, which improves the reliability of the obtained observed back EMF data, thereby enhancing the reliability of the obtained observed angle and angular velocity data, and ultimately improving the reliability of the positionless motor control. Furthermore, it also improves... Increasing the refresh rate of the back-EMF iteration reduces the ripple of the observed current, which can further improve the sinusoidal accuracy of the back-EMF observation. This reduces the difficulty of subsequent parameter adjustment. Taking the extraction of motor speed and rotor angle by the phase-locked loop as an example, the improved sinusoidal accuracy of the back-EMF observation is equivalent to a reduction in the input ripple of the phase-locked loop, which is beneficial to the overall robustness and thus improves the stability of motor control. By increasing the refresh rate of the back-EMF iteration, the ripple of the observed current and the back-EMF observation error are effectively reduced, thereby reducing the system's dependence on motor parameters and enhancing the robustness and stability of motor control under medium- and high-speed operating conditions.

[0068] Example 3

[0069] Figure 12 This is a structural block diagram of a motor control device provided in Embodiment 3 of the present invention. (See reference) Figure 12 The motor control device includes: a parameter acquisition module 310, an iteration module 320, and a motor control module 330; wherein, the parameter acquisition module 310 is used to acquire the voltage and current of the motor during operation; the iteration module 320 is used to determine the observed back EMF of the motor based on the voltage and current, and to perform multiple iterations on the observed back EMF; the motor control module 330 is used to process the observed back EMF after multiple iterations through a phase-locked loop to obtain the observed angle and angular velocity of the motor, so as to perform positionless control of the motor.

[0070] Optionally, when the back EMF is observed iterated N times, the phase-locked loop processing of the observed back EMF is performed once; the refresh frequency of the iterative process of observing the back EMF is the first refresh frequency, the refresh frequency of the phase-locked loop processing is the second refresh frequency, the first refresh frequency is N times the second refresh frequency, and N is greater than or equal to 10.

[0071] Optionally, the first refresh rate is 100 kHz and the second refresh rate is 10 kHz.

[0072] In one embodiment, the iteration module 320 includes a current calculation unit and an observed back EMF adjustment unit; wherein, the current calculation unit is used to calculate the current corresponding to the observed back EMF based on the observed back EMF; the observed back EMF determination unit is used to adjust the magnitude of the observed back EMF to obtain a new observed back EMF when the current corresponding to the observed back EMF is greater than or less than the current when the motor is running.

[0073] Optionally, the iteration module 320 is specifically used to iterate the observed back potential a preset number of times, where the preset number of times is greater than or equal to 10.

[0074] Optionally, the iteration module 320 includes: an observed back EMF determination unit and an iteration unit; wherein, the observed back EMF determination unit is used to determine the observed back EMF of the motor based on the voltage and current and the sliding mode control algorithm of the motor; the iteration unit is used to perform multiple iterations on the observed back EMF based on the sliding mode control algorithm.

[0075] This embodiment also provides a motor, which is controlled by the motor control method provided in any embodiment of the present invention to obtain the observed angle and angular velocity of the motor, so as to determine the current position of the motor based on the observed angle and angular velocity of the motor, thereby realizing positionless control of the motor.

[0076] Optionally, the motor is a permanent magnet synchronous motor.

[0077] Specifically, permanent magnet synchronous motors (PMSMs) are characterized by high efficiency and energy saving, high power density, and precise control. High efficiency and energy saving: PMSMs have no excitation winding losses, resulting in significantly higher operating efficiency than traditional motors and substantial energy savings. High power density: The high magnetic field strength of the permanent magnets in PMSMs allows for smaller size and lighter weight for the same power output, facilitating equipment miniaturization. Good control performance: The rotor and stator magnetic fields of PMSMs are strictly synchronized, providing a wide speed range, fast response, and precise control of speed and torque. Excellent power factor: The natural power factor of PMSMs is close to 1, reducing reactive power losses in applications such as power grids and improving power supply stability. High reliability: The rotor structure of PMSMs is simple, without carbon brushes or slip rings, resulting in low failure risk, low maintenance costs, and long service life. The advantages of PMSMs—high efficiency and energy saving, high power density, good control performance, excellent power factor, and high reliability—compared to asynchronous motors in size and energy efficiency, make them widely used in various fields. Permanent magnet synchronous motors are used in certain scenarios such as air compressors and underwater propulsion motors. Since the motors in these scenarios usually operate at medium and high speeds and constant power, there is basically no sudden load change. Permanent magnet synchronous motors are suitable for positionless control. Under medium and high speed conditions, the control method of this embodiment is used to perform positionless control on permanent magnet synchronous motors. It has strong robustness and can ensure the reliability and stability of positionless control of permanent magnet synchronous motors.

[0078] The motor control device and motor provided in this embodiment belong to the same inventive concept as the motor control method provided in any embodiment of the present invention, and have corresponding beneficial effects. For technical details not covered in this embodiment, please refer to the motor control method provided in any embodiment of the present invention.

[0079] Example 4

[0080] Figure 13 This is a schematic diagram of the structure of an electronic device provided in Embodiment 4 of the present invention. Figure 13 A block diagram of an exemplary device 412 suitable for implementing embodiments of the present invention is shown. Figure 13 The device 412 shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of the present invention.

[0081] like Figure 13 As shown, device 412 is represented as a general-purpose device. Components of device 412 may include, but are not limited to: one or more processors 416, storage device 428, and bus 418 connecting different system components (including storage device 428 and processor 416).

[0082] Bus 418 represents one or more of several bus architectures, including a memory device bus or memory device controller, a peripheral bus, a graphics acceleration port, a processor, or a local bus using any of the various bus architectures. Examples of these architectures include, but are not limited to, the Industry Subversive Alliance (ISA) bus, the Micro Channel Architecture (MAC) bus, the Enhanced ISA bus, the Video Electronics Standards Association (VESA) local bus, and the Peripheral Component Interconnect (PCI) bus.

[0083] Device 412 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by device 412, including volatile and non-volatile media, removable and non-removable media.

[0084] Storage device 428 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 430 and / or cache memory 432. Device 412 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, storage system 434 may be used to read and write non-removable, non-volatile magnetic media (… Figure 13 Not shown; usually referred to as a "hard drive"). Although Figure 13 Not shown, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk") and an optical disc drive for reading and writing to a removable non-volatile optical disc, such as a Compact Disc Read-Only Memory (CD-ROM), a Digital Video Disc Read-Only Memory (DVD-ROM), or other optical media. In these cases, each drive may be connected to bus 418 via one or more data media interfaces. Storage device 428 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the embodiments of the present invention.

[0085] A program / utility 440 having a set (at least one) of program modules 442 may be stored in, for example, a storage device 428. Such program modules 442 include, but are not limited to, an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include an implementation of a network environment. Program modules 442 typically perform the functions and / or methods described in the embodiments of the present invention.

[0086] Device 412 can also communicate with one or more external devices 414 (e.g., keyboard, pointing terminal, display 424, etc.), and with one or more terminals that enable a user to interact with device 412, and / or with any terminal that enables device 412 to communicate with one or more other computing terminals (e.g., network card, modem, etc.). This communication can be performed via input / output (I / O) interface 422. Furthermore, device 412 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 420. Figure 13 As shown, network adapter 420 communicates with other modules of device 412 via bus 418. It should be understood that, although not shown in the figure, other hardware and / or software modules can be used in conjunction with device 412, including but not limited to: microcode, terminal drivers, redundant processors, external disk drive arrays, Redundant Arrays of Independent Disks (RAID) systems, tape drives, and data backup storage systems.

[0087] The processor 416 executes various functional applications and data processing by running programs stored in the storage device 428, such as implementing the motor control method provided in the embodiments of the present invention, which includes:

[0088] Obtain the voltage and current of the motor during operation;

[0089] Based on voltage and current, the observed back EMF of the motor is determined, and the observed back EMF is iterated multiple times.

[0090] The observed back EMF after multiple iterations is processed by a phase-locked loop to obtain the observed angle and angular velocity of the motor, so as to perform positionless control of the motor.

[0091] Example 5

[0092] Embodiment 5 of the present invention provides a computer-readable storage medium storing a computer program thereon. When executed by a controller, the program implements the motor control method provided in the embodiments of the present invention, the method comprising:

[0093] Obtain the voltage and current of the motor during operation;

[0094] Based on voltage and current, the observed back EMF of the motor is determined, and the observed back EMF is iterated multiple times.

[0095] The observed back EMF after multiple iterations is processed by a phase-locked loop to obtain the observed angle and angular velocity of the motor, so as to perform positionless control of the motor.

[0096] The computer storage medium of this invention can be any combination of one or more computer-readable media. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0097] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0098] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including—but not limited to—wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0099] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or terminal. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0100] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, rearrangements, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A control method of an electric motor, characterized by, The method comprises: acquiring voltage and current of the motor during operation; determining an observed back electromotive force of the motor based on the voltage and the current, and performing multiple iterations on the observed back electromotive force; performing phase-locked loop processing on the observed back electromotive force after the multiple iterations to obtain an observed angle and an angular velocity of the motor, so as to perform positionless control on the motor; the multiple iterations on the observed back electromotive force comprise: calculating a current corresponding to the observed back electromotive force according to the observed back electromotive force; correspondingly adjusting a size of the observed back electromotive force to obtain a new observed back electromotive force when the current corresponding to the observed back electromotive force is greater than or less than the current of the motor during operation.

2. The control method of an electric motor according to claim 1, characterized by, the phase-locked loop processing on the observed back electromotive force is performed once when the observed back electromotive force is iterated N times; a refresh frequency of the iteration process of the observed back electromotive force is a first refresh frequency, and a refresh frequency of the phase-locked loop processing is a second refresh frequency, the first refresh frequency is N times of the second refresh frequency, and N is greater than or equal to 10.

3. The control method of an electric motor according to claim 2, characterized by, the first refresh frequency is 100 kHz, and the second refresh frequency is 10 kHz.

4. The control method of an electric motor according to claim 1, characterized by, the multiple iterations on the observed back electromotive force comprise: performing a preset number of iterations on the observed back electromotive force, the preset number being greater than or equal to 10.

5. The control method of an electric motor according to claim 1, characterized by, the determination of the observed back electromotive force of the motor based on the voltage and the current, and the multiple iterations on the observed back electromotive force comprise: determining the observed back electromotive force of the motor based on a sliding mode control algorithm of the motor according to the voltage and the current; performing multiple iterations on the observed back electromotive force based on the sliding mode control algorithm, and performing a filtering process once for each iteration of the observed back electromotive force.

6. The control method of an electric motor according to claim 5, characterized by the phase-locked loop processing is performed once when the filtering process is performed N times, and N is greater than or equal to 10.

7. A control device of an electric motor characterized by comprising: The method comprises: a parameter acquisition module configured to acquire voltage and current of the motor during operation; an iteration module configured to determine an observed back electromotive force of the motor based on the voltage and the current, and perform multiple iterations on the observed back electromotive force; a motor control module configured to perform phase-locked loop processing on the observed back electromotive force after the multiple iterations to obtain an observed angle and an angular velocity of the motor, so as to perform positionless control on the motor; the iteration module comprises: a current calculation unit configured to calculate a current corresponding to the observed back electromotive force according to the observed back electromotive force; an observed back electromotive force adjustment unit configured to correspondingly adjust a size of the observed back electromotive force to obtain a new observed back electromotive force when the current corresponding to the observed back electromotive force is greater than or less than the current of the motor during operation.

8. An electric machine characterized by The motor is controlled by the control method according to any one of claims 1-6.

9. The electric machine of claim 8, wherein, The motor is a permanent magnet synchronous motor.

Images