Permanent magnet synchronous motor sensorless control method, system and equipment

Abstract

The invention discloses a permanent magnet synchronous motor sensorless control method, system and device, and belongs to the field of synchronous motor control, and the method mainly comprises the steps: 1, constructing a reference model and an adjustable model of a permanent magnet synchronous motor sensorless identification system; 2, constructing an adaptive law according to the output of the reference model and the adjustable model; step 3, adopting a given value as input in an identification system, introducing a fuzzy self-tuning PI control algorithm in an identification link, and constructing an improved control algorithm of a permanent magnet synchronous motor sensorless; and 4, performing simulation verification on the improved control algorithm. Compared with a traditional MRAS method, the method is simple in calculation, is not affected by stator resistance change caused by temperature rise, achieves model convergence and stable operation of the system, and has good dynamic performance and steady-state performance.

Description

Technical Field

[0001] The present invention relates to the field of synchronous motor control, and in particular to a position sensorless control method, system and equipment for a permanent magnet synchronous motor. Background Art

[0002] Permanent magnet synchronous motor has the advantages of simple structure, small size, light weight, low loss and high efficiency. Compared with DC motor, it does not need commutator and brush of DC motor. Compared with asynchronous motor, it does not need reactive excitation current, so it has high efficiency, high power factor, large torque-to-inertia ratio, reduced stator current and stator resistance loss, measurable rotor parameters and good control performance. Compared with ordinary synchronous motor, it omits excitation device, simplifies structure and improves efficiency. Permanent magnet synchronous motor vector control system can achieve high precision, high dynamic performance and wide range of speed regulation or positioning control, so permanent magnet synchronous motor vector control system has attracted extensive attention of scholars at home and abroad.

[0003] Model Reference Adaptive System (MRAS) is widely used in sensorless control of permanent magnet synchronous motors due to its simple control method and superior performance. However, the adjustable model of this traditional control method contains stator resistance parameters. The temperature rise will affect the stator resistance value, and there are problems such as initial value of integration and DC bias, which makes the estimated speed inaccurate, thus affecting the speed identification accuracy and control accuracy. Summary of the invention

[0004] The purpose of the present invention is to overcome the technical problems existing in the prior art and to provide a position sensorless control method, system and device for a permanent magnet synchronous motor.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] In a first aspect, a position sensorless control method for a permanent magnet synchronous motor is provided, comprising the following steps:

[0007] Step 1: Construct a reference model and an adjustable model of a permanent magnet synchronous motor position sensorless identification system;

[0008] Step 2: constructing an adaptive law based on the outputs of the reference model and the adjustable model;

[0009] Step 3: Use the given value as input in the identification system, introduce the fuzzy self-tuning PI control algorithm in the identification link, and construct an improved control algorithm for permanent magnet synchronous motor without position sensor;

[0010] Step 4: Perform simulation verification on the improved control algorithm.

[0011] In some embodiments, the construction of the reference model includes:

[0012] In the synchronous rotating coordinate system, a virtual impedance variable Z is defined, where the d-axis and q-axis impedance expressions are:

[0013]

[0014] Among them, u d is the voltage component of the d-axis, u q is the voltage component of the q axis, i d is the current component of the d-axis, i q is the current component of the q axis, Z d , Z q It is only related to the speed of the motor. The instantaneous impedance difference between the d-axis and the q-axis of the permanent magnet synchronous motor in the synchronous rotating coordinate system is used as the reference model.

[0015]

[0016] In some embodiments, the adjustable model is:

[0017]

[0018] Among them, ω r is the electrical angular velocity, L d is the inductance component of the d-axis, L q is the inductance component of the q axis, Ψ f is the magnetic flux of the rotor permanent magnet.

[0019] In some embodiments, the given value includes given d-axis and q-axis current parameters.

[0020] In some embodiments, the fuzzy self-tuning PI control algorithm is introduced in the identification link to construct an improved control algorithm for a permanent magnet synchronous motor without a position sensor, including:

[0021] The original proportional parameter K p becomes its increment △K p , integral parameter K i becomes its increment △K i , K p , K i The expression is:

[0022] K P =K P '+ΔK P

[0023] K i =K i '+ΔK i

[0024] At this time, the input of the fuzzy controller is the error e and the error change rate e*, and the output is △Kp and △K i ; Define the basic domain of fuzzy sets as:

[0025] e, e*, △K p , △K i =(-4-3-2-101234)

[0026] Its fuzzy subset is:

[0027] e, e* = {NB NS ZE PS PB};

[0028] And establish membership function and fuzzy reasoning rule table according to the basic domain.

[0029] In a second aspect, a permanent magnet synchronous motor position sensorless control system is provided, comprising:

[0030] Model building module, used to build reference model and adjustable model of permanent magnet synchronous motor position sensorless identification system;

[0031] An adaptive law building module, used for building an adaptive law according to the outputs of the reference model and the adjustable model;

[0032] Improved control algorithm module, used to use given value as input in identification system, and introduce fuzzy self-tuning PI control algorithm in identification link to construct improved control algorithm of permanent magnet synchronous motor without position sensor;

[0033] The simulation verification module is used to perform simulation verification on the improved control algorithm.

[0034] In some embodiments, the model building module builds the reference model in the following manner:

[0035] In the synchronous rotating coordinate system, a virtual impedance variable Z is defined, where the d-axis and q-axis impedance expressions are:

[0036]

[0037] Among them, u d is the voltage component of the d-axis, u q is the voltage component of the q axis, i d is the current component of the d-axis, i q is the current component of the q axis, Z d , Z q It is only related to the speed of the motor. The instantaneous impedance difference between the d-axis and the q-axis of the permanent magnet synchronous motor in the synchronous rotating coordinate system is used as the reference model.

[0038]

[0039] In some embodiments, the adjustable model constructed by the model construction module is:

[0040]

[0041] Among them, ω r is the electrical angular velocity, L d is the inductance component of the d-axis, L q is the inductance component of the q axis, Ψ f is the magnetic flux of the rotor permanent magnet.

[0042] In a third aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, any one of the position sensorless control methods for a permanent magnet synchronous motor is implemented.

[0043] In a fourth aspect, an electronic device is provided, comprising a memory and a processor, wherein the memory stores computer instructions executable on the processor, and the processor executes any one of the position sensorless control methods for a permanent magnet synchronous motor when executing the computer instructions.

[0044] It should be further explained that the technical features corresponding to the above options can be combined or replaced with each other to form a new technical solution if there is no conflict.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] Under the condition of rotor magnetic field orientation, the present invention constructs the virtual impedance difference between the d-axis and the q-axis of the permanent magnet synchronous motor in the synchronous rotating coordinate system as an adaptive model. The given current parameters of the d-axis and the q-axis are used as the input of the identification system to reduce transient errors; at the same time, a fuzzy self-tuning PI control algorithm is introduced in the identification link to improve the speed identification accuracy. The reference model in the present invention does not contain speed information and stator resistance parameters. Compared with the traditional MRAS method, the calculation is simple and is not affected by the change of stator resistance caused by temperature rise. The model convergence and stable operation of the system are achieved, and it has good dynamic performance and steady-state performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A flow chart of a position sensorless control method for a permanent magnet synchronous motor shown in an embodiment of the present invention;

[0048] Figure 2 A schematic diagram of instantaneous impedance MRAS shown in an embodiment of the present invention;

[0049] Figure 3 A sensorless control scheme for a permanent magnet synchronous motor according to an embodiment of the present invention;

[0050] Figure 4A fuzzy PI control principle diagram shown in an embodiment of the present invention;

[0051] Figure 5 e, e*, K shown in the embodiment of the present invention p , K i Schematic diagram of membership function;

[0052] Figure 6 A waveform diagram of the system simulation running speed shown in an embodiment of the present invention;

[0053] Figure 7 The waveform diagram of the speed when the rated load is suddenly added is shown in the embodiment of the present invention;

[0054] Figure 8 This is a waveform diagram of the sudden application of rated load torque according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] The technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various configurations. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0056] It should be noted that the defects existing in the solutions in the above-mentioned prior art are the results obtained by the inventor after practice and careful research. Therefore, the discovery process of the above-mentioned problems and the solutions proposed in the embodiments of the present application for the above-mentioned problems below should all be the contributions made by the inventor to the present application in the process of invention and creation, and should not be understood as technical contents known to technical personnel in this field.

[0057] In view of the technical problems pointed out in the background technology, the embodiments provided by the present invention are as follows:

[0058] Example 1

[0059] Reference Figure 1 In an exemplary embodiment, a position sensorless control method for a permanent magnet synchronous motor is provided, comprising the following steps:

[0060] Step 1: Construct a reference model and an adjustable model of a permanent magnet synchronous motor position sensorless identification system;

[0061] Step 2: constructing an adaptive law based on the outputs of the reference model and the adjustable model;

[0062] Step 3: Use the given value as input in the identification system, introduce the fuzzy self-tuning PI control algorithm in the identification link, and construct an improved control algorithm for permanent magnet synchronous motor without position sensor;

[0063] Step 4: Perform simulation verification on the improved control algorithm.

[0064] Specifically, in the case of rotor magnetic field orientation, the mathematical model of the permanent magnet synchronous motor in the synchronous rotating coordinate system is:

[0065]

[0066] In the expression, u d ,u q is the voltage component of the d-axis and q-axis, i d ,i q are the current components of the d-axis and q-axis, R s is the stator resistance, ω r is the electrical angular velocity, L d , L q is the inductance component of the d-axis and q-axis, Ψ f is the magnetic flux of the rotor permanent magnet.

[0067] In the synchronous rotating coordinate system, a virtual impedance variable Z is defined, where the d-axis and q-axis impedance expressions are:

[0068]

[0069] Z d , Z q It is only related to the speed of the motor. The instantaneous impedance difference between the d and q axes of the permanent magnet synchronous motor in the synchronous rotating coordinate system can be used as the reference model in the model reference adaptive system, namely:

[0070]

[0071] Substituting (5) into (1) yields:

[0072]

[0073] Because when the motor runs to a steady state, the relevant differential term in equation (6) is 0, the above equation can be rearranged as:

[0074]

[0075] Formula (5) is used as the reference model, and formula (7) is used as the adjustable model to form an adaptive law, such as Figure 2As shown, it can be seen that the reference model (5) only contains voltage and current, and the adjustable model (7) contains speed information and does not contain stator resistance parameters. Therefore, when the stator resistance changes with temperature, it will not affect the speed estimated by the model used. Compared with the traditional MRAS solution, the speed control accuracy can be improved.

[0076] Permanent magnet motor sensorless control solution Figure 3 As shown, further observing equation (5) and equation (7), first, i d ,i q As the denominator, the system is more sensitive to its changes, especially when the motor is accelerating or decelerating, adding or removing loads, etc. d ,i q The transient component of is more obviously fluctuating. Moreover, formula (6) is established based on the steady-state model, ignoring the transient component. When considering its transient variables, the identification accuracy of the entire system will have a certain error, and even cause high-frequency oscillation of the electric speed. For this reason, the present invention adopts a given value as the input of the identification system. The given value fluctuates less than the actual value, is closer to the steady-state value, and has a smaller transient component. Therefore, using the given value will reduce the transient error.

[0077] Furthermore, the traditional PI controller has limited adjustment capability. For error signals with large fluctuations, it is difficult to take into account both steady-state performance and dynamic performance. The present invention introduces a fuzzy self-tuning PI control algorithm in the identification link of the model reference adaptive system (MRAS). The principle diagram is shown in FIG. Figure 4 shown.

[0078] In order to improve the response speed of the system, the original proportional term parameter K p becomes its increment △K p , integral parameter K i becomes its increment △K i , because of its small variation, it is more suitable for adaptive control modules with large error fluctuations, and can reduce the amount of calculation.

[0079] K p , K i The expression is:

[0080] K P =K P '+ΔK P (8)

[0081] K i =K i '+ΔK i (9)

[0082] At this time, the input of the fuzzy controller is the error e and the error change rate e*, and the output is △Kp, △K iThe basic domain of fuzzy sets is defined as:

[0083] e, e*, △Kp, △Ki=(-4-3-2-101234) (10)

[0084] Its fuzzy subset is:

[0085] e, e*={NB NS ZE PS PB} (11)

[0086] Membership function such as Figure 5 As shown, the fuzzy control rules can be obtained as shown in Table 1.

[0087] Table 1e, e*, △K p , △K i Fuzzy inference rules table

[0088]

[0089]

[0090] Finally, a simulation model was built to verify the control algorithm of the present invention. The simulation results are as follows: Figure 6 , 7 As shown in Figure 8, the results show that the method proposed in the present invention can stably operate in a closed loop, and the sensorless speed identification scheme is not affected by the changes in stator parameters caused by the temperature rise of the system operation.

[0091] Example 2

[0092] Based on the same inventive concept as that of Embodiment 1, a permanent magnet synchronous motor position sensorless control system is provided, comprising:

[0093] Model building module, used to build reference model and adjustable model of permanent magnet synchronous motor position sensorless identification system;

[0094] An adaptive law building module, used for building an adaptive law according to the outputs of the reference model and the adjustable model;

[0095] Improved control algorithm module, used to use given value as input in identification system, and introduce fuzzy self-tuning PI control algorithm in identification link to construct improved control algorithm of permanent magnet synchronous motor without position sensor;

[0096] The simulation verification module is used to perform simulation verification on the improved control algorithm.

[0097] It should be noted that each module of the system integrates the software and hardware corresponding to the functions of each step in the implementation method to achieve the same functions.

[0098] Example 3

[0099] Based on the same inventive concept as Example 1, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the permanent magnet synchronous motor position sensorless control method provided by the embodiment of the present invention is implemented. Based on such an understanding, the technical solution of this embodiment is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes various media that can store program codes, such as a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0100] Example 4

[0101] Based on the same inventive concept as Example 1, an electronic device is provided, including a memory and a processor, wherein the memory stores computer instructions that can be executed on the processor, and when the processor runs the computer instructions, the permanent magnet synchronous motor position sensorless control method provided in the embodiment of the present invention is executed.

[0102] The processor may be a single-core or multi-core central processing unit or a specific integrated circuit, or one or more integrated circuits configured to implement the present invention.

[0103] Embodiments of the subject matter and functional operations described in this specification may be implemented in: tangibly embodied computer software or firmware, computer hardware including the structures disclosed in this specification and their structural equivalents, or a combination of one or more of them. Embodiments of the subject matter described in this specification may be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on a tangible, non-transitory program carrier to be executed by a data processing device or to control the operation of the data processing device. Alternatively or additionally, the program instructions may be encoded on an artificially generated propagated signal, such as a machine-generated electrical, optical, or electromagnetic signal, which is generated to encode and transmit information to a suitable receiver device for execution by the data processing device.

[0104] The processes and logic flows described in this specification can be performed by one or more programmable computers executing one or more computer programs to perform corresponding functions by operating on input data and generating output. The processes and logic flows can also be performed by special purpose logic circuits, such as FPGAs (field programmable gate arrays) or ASICs (application-specific integrated circuits), and the apparatus can also be implemented as special purpose logic circuits.

[0105] Processors suitable for executing computer programs include, for example, general and / or special microprocessors, or any other type of central processing unit. Typically, the central processing unit will receive instructions and data from a read-only memory and / or a random access memory. The basic components of a computer include a central processing unit for implementing or executing instructions and one or more memory devices for storing instructions and data. Typically, the computer will also include one or more large-capacity storage devices for storing data, such as magnetic disks, magneto-optical disks, or optical disks, or the computer will be operably coupled to this large-capacity storage device to receive data from it or to transmit data to it, or both. However, the computer does not necessarily have such a device. In addition, the computer can be embedded in another device, such as a mobile phone, a personal digital assistant (PDA), a mobile audio or video player, a game console, a global positioning system (GPS) receiver, or a portable storage device such as a universal serial bus (USB) flash drive, just to name a few.

[0106] It should be understood that each box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a sequence different from that marked in the accompanying drawings. For example, two continuous boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs the specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0107] The above specific implementation methods are detailed descriptions of the present invention. It cannot be determined that the specific implementation methods of the present invention are limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions and substitutions can be made without departing from the concept of the present invention, which should be regarded as belonging to the protection scope of the present invention.

Claims

1. A position sensorless control method for a permanent magnet synchronous motor, characterized in that: The following steps are involved: Step 1: Construct a reference model and an adjustable model of a permanent magnet synchronous motor position sensorless identification system; Step 2: constructing an adaptive law based on the outputs of the reference model and the adjustable model; Step 3: Use the given value as input in the identification system, introduce the fuzzy self-tuning PI control algorithm in the identification link, and construct an improved control algorithm for permanent magnet synchronous motor without position sensor; Step 4: Perform simulation verification on the improved control algorithm.

2. The position sensorless control method of a permanent magnet synchronous motor according to claim 1, characterized in that: The construction of the reference model includes: In the synchronous rotating coordinate system, a virtual impedance variable Z is defined, where the d-axis and q-axis impedance expressions are: Among them, u d is the voltage component of the d-axis, u q is the voltage component of the q axis, i d is the current component of the d-axis, i q is the current component of the q axis, Z d , Z q It is only related to the speed of the motor. The instantaneous impedance difference between the d-axis and the q-axis of the permanent magnet synchronous motor in the synchronous rotating coordinate system is used as the reference model.

3. The position sensorless control method of a permanent magnet synchronous motor according to claim 1, characterized in that: The adjustable model is: Among them, ω r is the electrical angular velocity, L d is the inductance component of the d-axis, L q is the inductance component of the q axis, Ψ f is the rotor permanent magnet flux.

4. The position sensorless control method of a permanent magnet synchronous motor according to claim 1, characterized in that: The given values ​​include given d-axis and q-axis current parameters.

5. The position sensorless control method of a permanent magnet synchronous motor according to claim 1, characterized in that: The fuzzy self-tuning PI control algorithm is introduced in the identification link to construct an improved control algorithm for the permanent magnet synchronous motor without position sensor, including: The original proportional parameter K p becomes its increment △K p , integral parameter K i becomes its increment △K i , K p , K i The expression is: K P =K P '+ΔK P K i =K i '+ΔK i At this time, the input of the fuzzy controller is the error e and the error change rate e*, and the output is △K p and △K i ; Define the basic domain of fuzzy sets as: e,e*,△K p ,△K i =(-4 -3 -2 -1 0 1 2 3 4) Its fuzzy subset is: e, e* = {NB NS ZE PS PB}; And establish membership function and fuzzy reasoning rule table according to the basic domain.

6. A permanent magnet synchronous motor position sensorless control system, characterized in that: include: Model building module, used to build reference model and adjustable model of permanent magnet synchronous motor position sensorless identification system; An adaptive law building module, used for building an adaptive law according to the outputs of the reference model and the adjustable model; Improved control algorithm module, used to use given value as input in identification system, and introduce fuzzy self-tuning PI control algorithm in identification link to construct improved control algorithm of permanent magnet synchronous motor without position sensor; The simulation verification module is used to perform simulation verification on the improved control algorithm.

7. The permanent magnet synchronous motor position sensorless control system according to claim 6, characterized in that: The model building module builds the reference model in the following ways: In the synchronous rotating coordinate system, a virtual impedance variable Z is defined, where the d-axis and q-axis impedance expressions are: Among them, u d is the voltage component of the d-axis, u q is the voltage component of the q axis, i d is the current component of the d-axis, i q is the current component of the q axis, Z d , Z q It is only related to the speed of the motor. The instantaneous impedance difference between the d-axis and the q-axis of the permanent magnet synchronous motor in the synchronous rotating coordinate system is used as the reference model.

8. The permanent magnet synchronous motor position sensorless control system according to claim 6, characterized in that: The adjustable model constructed by the model construction module is: Among them, ω r is the electrical angular velocity, L d is the inductance component of the d-axis, L q is the inductance component of the q axis, Ψ f is the rotor permanent magnet flux.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the position sensorless control method for a permanent magnet synchronous motor as described in any one of claims 1 to 5 is implemented.

10. An electronic device comprising a memory and a processor, wherein the memory stores computer instructions that can be executed on the processor, wherein: When the processor runs the computer instructions, it executes the permanent magnet synchronous motor position sensorless control method described in any one of claims 1-5.

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