Permanent magnet synchronous motor sensorless control method

Abstract

The invention relates to the technical field of motor control, and particularly provides a permanent magnet synchronous motor sensorless control method, which comprises the following steps of: designing a front-stage non-smooth extended state observer according to a voltage equation of a permanent magnet synchronous motor, and estimating the back electromotive force of the motor by using the front-stage non-smooth extended state observer; calculating the position error of the motor rotor by using the back electromotive force estimated value; and designing a post-stage non-smooth extended state observer according to the dynamic model of the permanent magnet synchronous motor, taking the position error as an input quantity, and extracting and outputting motor rotor position estimation and electric angular velocity estimation through the post-stage non-smooth extended state observer. According to the invention, the two cascaded non-smooth expansion state observers replace a traditional sliding mode observer and an orthogonal phase-locked loop structure, so that the extraction precision of position and speed information is effectively improved, and the dynamic performance and the steady-state performance of the permanent magnet synchronous motor sensorless sensor are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor control, and particularly relates to a sensorless control method for a permanent magnet synchronous motor. Background Art

[0002] Due to advantages such as high torque density, fast dynamic performance, and good reliability, permanent magnet synchronous motors are widely used in industries such as transportation, manufacturing equipment, and household appliances. Usually, the rotor position information of the motor can be obtained through position sensors such as encoders or resolvers. However, these sensors are not only expensive but also very sensitive to environmental constraints such as vibration and temperature. To overcome these problems, sensorless control algorithms have been deeply studied and developed. Among them, the method based on the back electromotive force model is mainly used for medium and high speed scenarios of the motor, and this method estimates the rotor position through the fundamental frequency back electromotive force. The traditional classical method is to construct a sliding mode observer using the stator voltage and stator current based on the voltage equation of the motor to obtain the estimated back electromotive force, and then extract the rotor angle and position information from the estimated back electromotive force through an orthogonal phase-locked loop and a low-pass filter. However, as the speed of the motor changes rapidly during operation, the estimation ability of the orthogonal phase-locked loop and the low-pass filter for time-varying disturbances is weak and cannot respond quickly to speed changes, resulting in lags in speed and position estimation, thus affecting the accuracy and stability of the motor. Summary of the Invention

[0003] In view of this, the present invention aims to provide a sensorless control method for a permanent magnet synchronous motor, which accurately extracts the motor position and speed information through a two-stage nonsmooth observer, improving the dynamic performance and steady-state performance of the sensorless permanent magnet synchronous motor.

[0004] To achieve the above object, the technical solution of the present invention is realized as follows: The first aspect of the present invention provides a sensorless control method for a permanent magnet synchronous motor, including: designing a front-stage nonsmooth extended state observer based on the voltage equation of the permanent magnet synchronous motor, where the front-stage nonsmooth extended state observer is used to estimate the back electromotive force; Calculating the rotor position error of the motor according to the back electromotive force estimated by the front-stage nonsmooth extended state observer; Designing a rear-stage nonsmooth extended state observer based on the dynamic model of the permanent magnet synchronous motor, where the rear-stage nonsmooth extended state observer calculates and obtains the rotor position estimate and the electrical angular velocity estimate using the rotor position error of the motor.

[0005] Preferably, the voltage equation of the permanent magnet synchronous motor is: ; Wherein, represents the actual stator current of the motor on the axis, Represents the motor The actual stator current of the shaft, Represents the motor The actual stator voltage of the shaft, Represents the motor The actual stator voltage of the shaft, Represents the stator resistance of the motor, Represents the stator inductance of the motor, Represents the motor Back electromotive force of the shaft, Represents the motor Back electromotive force of the shaft, Represents the time variable.

[0006] Preferably, the design process of the pre-stage non-smooth extended state observer includes: Taking The back electromotive forces of the shaft and The shaft as the extended states, and constructing the extended state system equation as: ; Wherein, , representing the derivative of the back electromotive force of the motor of the shaft, , representing the derivative of the back electromotive force of the motor of the shaft, is a gain coefficient of the pre-stage non-smooth extended state observer, , , representing the estimated value of the stator current of the motor of the shaft and the actual stator current , , representing the estimated value of the stator current of the motor of the shaft and the actual stator current , representing the change value of the current error of the motor of the shaft after being processed by the non-linear function, , representing the change value of the current error of the motor of the shaft after being processed by the non-linear function; Combining the voltage equation of the permanent magnet synchronous motor and the extended state system equation, the designed pre-stage non-smooth extended state observer is: ; Wherein, and are the gain coefficients of the pre-stage non-smooth extended state observer, and are the gain coefficients of the current error term, , , and are the coefficients in the non-smooth function, , , and are the parameter powers of the non-smooth function, , , , , , .

[0007] Preferably, the motor rotor position error is: ; wherein, represents the actual rotor position, represents the estimated value of the rotor position, represents the motor back electromotive force error, represents the estimated value of the motor axis back electromotive force output by the previous-stage non-smooth extended state observer, represents the estimated value of the motor axis back electromotive force output by the previous-stage non-smooth extended state observer.

[0008] Preferably, the dynamic model of the permanent magnet synchronous motor is: ; wherein, represents the moment of inertia, represents the mechanical angular velocity, represents the electromagnetic torque coefficient, represents the reference current of the q-axis of the motor, represents the load disturbance, represents the viscous friction coefficient.

[0009] Preferably, the post-stage non-smooth extended state observer is: ; wherein, and are the gain coefficients of the post-stage non-smooth extended state observer, and are the gain coefficients of the current error term, , , and are the coefficients in the non-smooth function, , , and is the parameter power of a non-smooth function, , , , , represents the estimated value of the rotor position is the derivative of, represents the derivative of the estimated value of the electrical angular velocity, represents the control gain, represents the q-axis reference current.

[0010] The second aspect of the present invention provides a computer device, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein, the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the sensorless control method for a permanent magnet synchronous motor.

[0011] The third aspect of the present invention provides a non-transitory computer-readable storage medium storing computer instructions for causing a computer to execute the sensorless control method for a permanent magnet synchronous motor.

[0012] Compared with the prior art, the present invention can achieve the following beneficial effects: The present invention extracts the motor position and speed information through a cascaded two-stage non-smooth extended state observer, replacing the structural design of the sliding mode observer and the orthogonal phase-locked loop in the traditional scheme, effectively improving the back electromotive force reconstruction accuracy and the rotor parameter estimation performance. Compared with the traditional combination scheme of the phase-locked loop and the super-twisting observer, the cascaded observer of the present invention adopts a second-order non-smooth function, which can further reduce the influence of the non-linear term in the traditional super-twisting sliding mode function on the rotor position estimation, further reduce the chattering, and improve the estimation accuracy of the position and speed information.

[0013] Compared with the traditional super-twisting sliding mode observer scheme, both the front-stage non-smooth extended state observer and the rear-stage non-smooth extended state observer of the present invention are provided with linear terms, which can effectively improve the convergence speed of the position estimation and the speed estimation, avoiding the problems of too slow convergence speed, even infinite-time convergence and non-convergence in the traditional scheme. The present invention can quickly respond to the motor speed change, which helps to improve the dynamic performance of the sensorless drive system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings: Figure 1It is the design flowchart of the sensorless control method for permanent magnet synchronous motors according to the embodiments of the present invention; Figure 2 It is the block diagram of the sensorless control system for permanent magnet synchronous motors according to the embodiments of the present invention; Figure 3 It is the schematic diagram of estimating the back electromotive force based on the front-stage nonsmooth extended state observer according to the embodiments of the present invention; Figure 4 It is the schematic diagram of obtaining the rotor position estimation and the electrical angular velocity estimation based on the rear-stage nonsmooth extended state observer according to the embodiments of the present invention; Figure 5 It is the structural diagram of the rear-stage nonsmooth extended state observer according to the embodiments of the present invention; Figure 6 It is the comparison diagram of the estimated motor speed and the actual speed when using the combined scheme of the traditional super-twisting sliding mode state observer and the phase-locked loop during the speed ramp up and down; Figure 7 It is the comparison diagram of the estimated motor speed and the actual speed when using the sensorless control method for permanent magnet synchronous motors provided by the embodiments of the present invention during the speed ramp up and down; Figure 8 It is the comparison diagram of the error curves of the estimated speeds between the proposed scheme of the present invention and the traditional scheme during the speed ramp up and down; Figure 9 It is the comparison diagram of the change curves of the motor rotor position estimation errors between the proposed scheme of the present invention and the traditional scheme when the actual motor speed is 1000 rpm. Detailed implementation manners

[0015] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. Similar elements in different embodiments are labeled with related similar element numbers. In the following embodiments, many details are described to make the present invention better understood. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, methods. In some cases, some operations related to the present invention are not shown or described in the specification, which is to avoid the core part of the present invention being overwhelmed by excessive description. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0016] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other to form various implementation manners. At the same time, the steps or actions in the method description can also be reordered or adjusted in an obvious manner by those skilled in the art. Therefore, the various sequences in the specification and drawings are only for clearly describing a certain embodiment and do not mean that they are the necessary sequences, unless it is otherwise stated that a certain sequence must be followed.

[0017] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "a plurality" is two or more.

[0018] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0019] The present invention will be described in detail below with reference to the drawings and in combination with embodiments.

[0020] Please refer to Figure 1 , in an embodiment of the present invention, a sensorless control method for a permanent magnet synchronous motor based on the cascade of two non-smooth extended state observers is provided, which can be applied to a sensorless control system for a permanent magnet synchronous motor as shown in Figure 2 . The system specifically includes: A three-phase inverter, whose function is: converting the DC bus voltage into three-phase alternating current, and then driving a permanent magnet synchronous motor (PMSM).

[0021] The current detection module has the following functions: detecting the three-phase current of the permanent magnet synchronous motor , and , and convert the three-phase current into the current in the two-phase stationary coordinate system and .

[0022] Follow-up current and It will be further converted into the current in the rotating coordinate system and .

[0023] The cascaded non-smooth observer designed by the embodiment of the present invention has the following functions: observing the motor state and obtaining the rotor position estimate. and electrical angular velocity estimation .

[0024] The speed controller has the following functions: and the estimated electrical angular velocity of the feedback After the difference is made, the reference current is generated , .

[0025] The current controller has the following functions: , , and then the current in the rotating coordinate system of the feedback and Make a difference and generate a voltage reference value and .

[0026] Subsequent voltage and It will be further converted into the voltage in the two-phase stationary coordinate system and .

[0027] The space vector pulse width modulation module (SVPWM) has the following functions: and Generate 6 PWM signals (PWM1-PWM6) to control the switching state of the inverter.

[0028] The rotor position estimation and the electrical angular velocity estimation are obtained by the position sensorless control method for a permanent magnet synchronous motor provided by an embodiment of the present invention, which specifically includes the following steps: S1: First, establish the voltage equation of the permanent magnet synchronous motor: (1) in, Indicates motor The actual stator current of the axis, indicating the motor The actual stator current of the axis, indicating the motor The actual stator voltage of the axis, indicating the motor The actual stator voltage of the axis, indicating the stator resistance of the motor, indicating the stator inductance of the motor, indicating the motor Back electromotive force of the axis, indicating the motor Back electromotive force of the axis, indicating the time variable, indicating taking the time differential.

[0029] Please refer to Figure 3 , analyze the voltage equation of the permanent magnet synchronous motor. On this basis, design a pre-stage non-smooth extended state observer, and use the pre-stage non-smooth extended state observer to estimate the back electromotive force components, specifically including the following process: Let the back electromotive forces of the axis and the axis and be defined as the extended states. Further, the extended state system equation can be constructed as: (2) where, represents the derivative of the back electromotive force of the motor axis, indicating the rate of change of the back electromotive force, represents the derivative of the back electromotive force of the motor axis, indicating the rate of change of the back electromotive force, is a gain coefficient in the pre-stage non-smooth extended state observer, , represents the difference between the estimated value of the stator current of the motor axis and the actual stator current , , represents the difference between the estimated value of the stator current of the motor axis and the actual stator current , represents the change value of the current error of the motor axis after being processed by the non-linear function, represents the change value of the current error of the motor axis after being processed by the non-linear function.

[0030] Based on the voltage equation (1) of the permanent magnet synchronous motor and the extended state system equation (2), the front-stage non-smooth extended state observer is designed as follows: (3) where, is another gain coefficient in the front-stage non-smooth extended state observer, and are the gain coefficients of the current error term, , , and are the coefficients in the non-smooth function, , , and are the parameter powers of the non-smooth function, , , the symbolic operation rules in the non-smooth function are defined as: ; that is: , , , , where, is the set of positive real numbers, and are both variables.

[0031] The front-stage non-smooth extended state observer estimates the extended state through non-linear processing, which can compensate for the uncertainties and disturbances of the system. Thus, the estimated values of the back electromotive force on the axis and the axis, and , can be obtained respectively through the front-stage non-smooth extended state observer.

[0032] S2: Please refer to Figure 4 , based on the estimated values of the back electromotive force and obtained by the front-stage non-smooth extended state observer in S1, the back electromotive force error containing the motor angle information can be further designed as: (4) where, represents the actual rotor position, represents the estimated value of the rotor position. Therefore, the rotor error can be defined.

[0033] Generally, when the rotor position error is small enough, where the rotor position error being small enough means , at this time, it is usually considered that , the rotor position error of the motor can be calculated at this time It is: (5) Thus, the rotor position error of the motor is calculated from the estimated back electromotive force output by the front-stage nonsmooth extended state observer.

[0034] S3: Establish the dynamic model of the permanent magnet synchronous motor as: (6) Among them, represents the moment of inertia, represents the mechanical angular velocity, represents the electromagnetic torque coefficient, represents the reference current of the q-axis of the motor, represents the load disturbance, represents the viscous friction coefficient.

[0035] To suppress the system disturbance, the dynamic model of the permanent magnet synchronous motor expressed by Equation (7) is further rewritten as: (7) Among them, represents the electrical angular velocity, , represents the number of pole pairs of the motor, represents the derivative of the electrical angular velocity, used to represent the change rate of the electrical angular velocity of the motor, represents the control gain, represents the total disturbance of the motor system, represents the reference current of the q-axis of the motor.

[0036] Due to the existence of the equation , therefore, based on the rewritten form of the dynamic model of the permanent magnet synchronous motor expressed by Equation (7), the following back-stage nonsmooth extended state observer is designed: (8) Among them, and are the gain coefficients of the back-stage nonsmooth extended state observer, and are the gain coefficients of the current error term, , , and are the coefficients in the nonsmooth function, , , and are the parameter powers of the nonsmooth function, , , , , represents the estimated value of the rotor position derivative of, represents the derivative of the estimated value of the electrical angular velocity.

[0037] By means of the subsequent non-smooth extended state observer as Figure 5 shown, the estimated rotor position can be output and the estimated electrical angular velocity .

[0038] To verify the effectiveness of the sensorless control method for permanent magnet synchronous motors based on the cascade of double non-smooth observers proposed in the present invention, Method (a): the combination scheme of the traditional super-twisting sliding mode observer and the phase-locked loop, and Method (b): the sensorless control method for permanent magnet synchronous motors proposed in the embodiment of the present invention, were subjected to a simulation comparison experiment under the same conditions.

[0039] It should be noted that during the simulation experiment, the speed controllers and current controllers used in Methods (a) and (b) are the same. The parameters in the speed controller are respectively , , and the parameters in the current controller are respectively , , and the observer gain coefficients are respectively , , , , , , . The additional parameters involved in the sensorless control method for permanent magnet synchronous motors are: the non-smooth observer power coefficients are respectively , .

[0040] Obtained through simulation: As Figure 6 shown, Figure 6 in (a), when the motor speed ramps up and down, the curve of the actual speed of the motor during speed estimation by the combination scheme of the traditional super-twisting sliding mode state observer and the phase-locked loop (STO+PLL); Figure 6 in (b), when the motor speed ramps up and down, the curve of the estimated speed of the motor obtained by using the combination scheme of the traditional super-twisting sliding mode state observer and the phase-locked loop (STO+PLL) for speed estimation.

[0041] As Figure 7 shown, Figure 7 in (a), when the motor speed ramps up and down, the curve of the actual speed of the motor during speed estimation by the sensorless control method for permanent magnet synchronous motors of the present invention;Figure 7 In Figure (b), it is the curve of the estimated speed of the motor obtained by using the sensorless control method of the permanent magnet synchronous motor of the present invention for speed estimation when the motor speed ramps up and down.

[0042] As Figure 8 shown, Figure 8 In Figure (a), it is the error curve of the estimated speed relative to the actual speed obtained by using the combined scheme of the traditional super-twisting sliding mode state observer and the phase-locked loop for speed estimation when the motor speed ramps up and down; Figure 8 In Figure (b), it is the error curve of the estimated speed relative to the actual speed obtained by using the sensorless control method of the permanent magnet synchronous motor of the present invention for speed estimation when the motor speed ramps up and down.

[0043] From Figure 6 , Figure 7 and Figure 8 it can be seen that whether in different speed steady states or during the speed ramping up and down, when using the method proposed in the present invention for speed estimation, the speed error is significantly smaller than that of the traditional method, which shows the superiority and progressiveness of the sensorless control method of the permanent magnet synchronous motor of the present invention in speed dynamic estimation.

[0044] As Figure 9 shown, Figure 9 In Figure (a), it is the curve of the change of the rotor position estimation error obtained by using the combined scheme of the traditional super-twisting sliding mode state observer and the phase-locked loop at a speed of 1000 rpm, Figure 9 In Figure (b), it is the curve of the change of the rotor position estimation error obtained by using the sensorless control method of the permanent magnet synchronous motor of the present invention at a speed of 1000 rpm. From Figure 9 it can be seen that the rotor position estimation error obtained by the method of the present invention is smaller, the position estimation is more accurate, and the estimation stability is better.

[0045] In summary, compared with the traditional scheme, the present invention has made great progress in the estimation accuracy and stability of position and speed information.

[0046] Correspondingly, according to the above embodiments of the present invention, the present invention also provides a computer device and a non-transitory computer-readable storage medium storing computer instructions.

[0047] The computer device is presented in the form of a general-purpose computing device. The computer device is intended to represent various forms of digital computers, such as, a laptop computer, a desktop computer, a workbench, a personal digital assistant, a server, a blade server, a mainframe computer, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as, a personal digital processor, a cellular phone, a smart phone, a wearable device, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are only examples and are not intended to limit the implementation of the invention described herein and / or claimed.

[0048] The components of the computer device can include, but are not limited to: one or more processors or processing units, a system memory, and a bus that connects different system components (including the system memory and the processing unit).

[0049] The bus represents one or more of several types of bus structures, including a memory bus or a memory controller, a peripheral bus, a graphics acceleration port, a processor, or a local bus using any of the various bus structures. By way of example, these architectures include, but are not limited to, Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MAC) bus, Enhanced ISA bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus.

[0050] The computer device typically includes a variety of computer system readable media. These media can be any available media that can be accessed by the computer device, including volatile and non-volatile media, removable and non-removable media.

[0051] The system memory can include computer system readable media in the form of volatile memory, such as random access memory (RAM) and / or cache memory. The computer device can further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, a storage system can be used for reading and writing non-removable, non-volatile magnetic media.

[0052] A program / utility having a set (at least one) of program modules can be stored, for example, in the memory. Such program modules 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. The program modules generally execute the functions and / or methods in the embodiments described herein.

[0053] The computer device can also communicate with one or more external devices (such as a keyboard, a pointing device, a display, etc.), and can also communicate with one or more devices that enable a user to interact with the computer device, and / or communicate with any device that enables the computer device to communicate with one or more other computing devices (such as a network card, a modem, etc.). Such communication can be carried out through an input / output (I / O) interface. Moreover, the computer device can also communicate with one or more networks (such as a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through a network adapter. The network adapter communicates with other modules of the computer device through a bus.

[0054] The processing unit executes various functional applications and data processing by running programs stored in the system memory, for example, implementing the sensorless control method for a permanent magnet synchronous motor provided by the embodiments of the present invention.

[0055] The embodiments of the present invention also provide a non-transitory computer-readable storage medium storing computer instructions, on which a computer program is stored. When the program is executed by a processor, it implements the sensorless control method for a permanent magnet synchronous motor provided by all the embodiments of the present application.

[0056] The computer storage medium of the embodiments of the present invention can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. More specific examples (a non-exhaustive list) of the computer-readable storage medium include: an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, the computer-readable storage medium can be any tangible medium that contains or stores a program, and the program can be used by or combined with an instruction execution system, apparatus, or device.

[0057] The computer-readable signal medium can include a data signal propagated in a baseband or as part of a carrier wave, which carries the computer-readable program code. Such a propagated data signal can take various forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination of the above. The computer-readable signal medium can also be any computer-readable medium other than the computer-readable storage medium, and the computer-readable medium can send, propagate, or transmit a program for use by or in combination with an instruction execution system, apparatus, or device.

[0058] The program code contained on a computer-readable medium can be transmitted using any appropriate medium, including but not limited to wireless, wire, optical fiber cable, RF, etc., or any suitable combination of the foregoing. The computer program code for performing the operations of the present invention can be written in one or more programming languages or combinations thereof. The programming languages include object-oriented programming languages such as Java, Smalltalk, C++, and also include conventional procedural programming languages - such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, executed as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through 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., by connecting through the Internet using an Internet service provider).

[0059] In summary, the above description is only a preferred embodiment of this specification and is not intended to limit the protection scope of this specification. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of this specification shall be included within the protection scope of this specification.

[0060] The systems, devices, modules or units illustrated in one or more of the above embodiments can be specifically implemented by computer chips or entities, or implemented by products with certain functions. A typical implementation device is a computer. Specifically, the computer can be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or any combination of these devices.

[0061] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, commodity or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, commodity or device comprising the element.

[0062] Each embodiment in this specification is described in a progressive manner. For the identical or similar parts among the embodiments, reference can be made to each other, and the differences between each embodiment and other embodiments are emphasized. In particular, for system embodiments, since they are basically similar to method embodiments, they are described relatively simply, and reference can be made to the relevant parts of the method embodiments for the relevant content.

[0063] The specific embodiments of this specification are described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve the desired result. Additionally, the processes depicted in the figures do not necessarily require the particular order or sequential order shown to achieve the desired result. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A position sensorless control method for a permanent magnet synchronous motor, characterized in that: include: Designing a front-stage non-smooth extended state observer based on the permanent magnet synchronous motor voltage equation, wherein the front-stage non-smooth extended state observer is used to estimate the back electromotive force; Calculating the motor rotor position error according to the back electromotive force estimated by the previous stage non-smooth extended state observer; A subsequent non-smooth extended state observer is designed based on a permanent magnet synchronous motor dynamics model, wherein the subsequent non-smooth extended state observer uses the motor rotor position error calculation to obtain a rotor position estimate and an electrical angular velocity estimate.

2. The position sensorless control method of a permanent magnet synchronous motor according to claim 1, characterized in that: The voltage equation of the permanent magnet synchronous motor is: ； in, Indicates motor The actual stator current of the shaft, Indicates motor The actual stator current of the shaft, Indicates motor The actual stator voltage of the shaft, Indicates motor The actual stator voltage of the shaft, represents the stator resistance of the motor, represents the stator inductance of the motor, Indicates motor The back EMF of the shaft, Indicates motor The back EMF of the shaft, Represents a time variable.

3. The position sensorless control method for a permanent magnet synchronous motor according to claim 2, characterized in that: The design process of the front-stage non-smooth extended state observer includes: Will Axis and The back electromotive force of the shaft is defined as the expansion state, and the expansion state system equation is constructed as: ； in, , indicating the motor The derivative of the shaft back EMF, , indicating the motor The derivative of the shaft back EMF, is a gain coefficient of the previous non-smooth extended state observer, , Indicates motor Estimated value of the stator current of the shaft The actual stator current The difference, , Indicates motor Estimated value of the stator current of the shaft The actual stator current The difference, Indicates motor The change in the axis current error after being processed by the nonlinear function, Indicates motor The change of the axis current error after being processed by the nonlinear function; Combining the permanent magnet synchronous motor voltage equation and the extended state system equation, the front-stage non-smooth extended state observer is designed as: ； in, and is the gain coefficient of the previous non-smooth extended state observer, and is the gain factor of the current error term, , , and are coefficients in non-smooth functions, , , and is the parameter power of a non-smooth function, , , , , , .

4. The position sensorless control method of a permanent magnet synchronous motor according to claim 1, characterized in that: The motor rotor position error for: ； in, represents the actual rotor position, represents the estimated value of the rotor position, represents the motor back EMF error, The motor output of the non-smooth extended state observer of the previous stage Axis back EMF estimate, The motor output of the non-smooth extended state observer of the previous stage Axis back EMF estimate.

5. The position sensorless control method of a permanent magnet synchronous motor according to claim 1, characterized in that: The permanent magnet synchronous motor dynamic model is: ； in, represents the moment of inertia, represents the mechanical angular velocity, represents the electromagnetic torque coefficient, Indicates the motor q-axis reference current, represents the load disturbance, represents the viscous friction coefficient.

6. The position sensorless control method of a permanent magnet synchronous motor according to claim 1, characterized in that: The latter non-smooth extended state observer is: ； in, and is the gain coefficient of the subsequent non-smooth extended state observer, and is the gain factor of the current error term, , , and are coefficients in non-smooth functions, , , and is the parameter power of a non-smooth function, , , , , Represents the estimated value of the rotor position The derivative of represents the derivative of the electrical angular velocity estimate, represents the control gain, Represents the q-axis reference current.

7. A computer device, characterized in that: include: at least one processor; and, a memory communicatively coupled to the at least one processor; The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the permanent magnet synchronous motor position sensorless control method described in any one of claims 1 to 6.

8. A non-transitory computer-readable storage medium storing computer instructions, characterized in that: The computer instructions are used to enable the computer to execute the position sensorless control method for a permanent magnet synchronous motor according to any one of claims 1 to 6.

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