Rotating speed estimation method for position-sensorless permanent magnet synchronous motor, system, and apparatus

Abstract

A rotating speed estimation method for a position-sensorless permanent magnet synchronous motor, a system, and an apparatus. The method comprises: acquiring a d-axis stator current and a d-axis stator voltage of a motor in a current control period; reconstructing the d-axis stator current and the d-axis stator voltage in the current control period on the basis of rotor flux linkage and d-axis inductance of the motor to obtain a d-axis extended current and a d-axis extended voltage; and inputting the d-axis extended current and the d-axis extended voltage in the current control period into an adaptive observer to obtain a rotating speed estimation value and a rotor position estimation value of the motor in the current control period. According to the rotating speed estimation method in the present application, by means of the adaptive observer, the rotating speed and rotor position estimation of a salient pole permanent magnet synchronous motor can be achieved, the rotating speed and rotor position estimation of a non-salient pole permanent magnet synchronous motor can also be achieved, and the precision of the rotating speed and rotor position estimation of the motor is guaranteed.

Description

Speed ​​estimation method, system and device for sensorless permanent magnet synchronous motor

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202410008884.9, filed on January 2, 2024, entitled “Speed ​​Estimation Method, System and Apparatus for Sensorless Permanent Magnet Synchronous Motor”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of electrical equipment technology, specifically to a method, system, and device for estimating the speed of a sensorless permanent magnet synchronous motor. Background Technology

[0004] In the driving process of permanent magnet synchronous motors (PMSMs), to ensure stable operation, it is necessary to monitor the motor speed and rotor position in real time to achieve precise control of speed and current. In related technologies, a tangent saturation function is typically used as the sliding surface control function of the flux linkage sliding mode observer to estimate the motor speed and rotor position angle.

[0005] Obtaining the motor speed and rotor position is crucial for the motor drive system. Although the above technical solution can estimate the motor speed and rotor position, it is based on a non-salient pole permanent magnet synchronous motor and cannot be applied to a salient pole permanent magnet synchronous motor.

[0006] Summary of the Invention

[0007] In view of the above problems, this application provides a method, system and device for speed estimation of a sensorless permanent magnet synchronous motor. The adaptive observer can estimate the speed and rotor position of both salient pole permanent magnet synchronous motors and non-salient pole permanent magnet synchronous motors, thus expanding the applicability of the control method while ensuring the accuracy of the motor speed and rotor position estimation.

[0008] In a first aspect, this application provides a speed estimation method for a sensorless permanent magnet synchronous motor, comprising: acquiring the d-axis stator current and d-axis stator voltage of the motor in the current control cycle; reconstructing the d-axis stator current and d-axis stator voltage of the current control cycle based on the rotor flux linkage and d-axis inductance of the motor in the current control cycle to obtain the d-axis extended current and d-axis extended voltage of the current control cycle; inputting the d-axis extended current and d-axis extended voltage of the current control cycle to an adaptive observer to obtain the speed estimate and rotor position estimate of the motor in the current control cycle; wherein, the adaptive observer is determined based on the voltage equation of the motor, the voltage equation including the d-axis inductance and q-axis inductance of the motor.

[0009] In the technical solution of this application embodiment, during motor operation, the d-axis stator current and d-axis stator voltage of the motor in the current control cycle are acquired. Based on the rotor flux linkage and d-axis inductance of the motor in the current control cycle, the d-axis stator current and d-axis stator voltage of the current control cycle are reconstructed to obtain the d-axis extended current and d-axis extended voltage of the current control cycle. The d-axis extended current and d-axis extended voltage of the current control cycle are input to an adaptive observer to obtain the estimated speed and rotor position of the motor in the current control cycle. The adaptive observer is determined based on the motor's voltage equation, which includes the motor's d-axis inductance and q-axis inductance. Therefore, the first adaptive observer is determined based on the voltage equation including the motor's d-axis inductance and q-axis inductance, enabling the method to estimate the speed and rotor position of both salient-pole permanent magnet synchronous motors and non-salient-pole permanent magnet synchronous motors, expanding the applicability of the control method while ensuring the accuracy of the motor's speed and rotor position estimation.

[0010] In some embodiments, reconstructing the d-axis stator current and d-axis stator voltage of the current control cycle based on the rotor flux linkage and the d-axis inductance of the motor in the current control cycle to obtain the d-axis extended current and d-axis extended voltage of the current control cycle includes: obtaining the sum of the d-axis equivalent current generated by the rotor flux linkage on the d-axis inductance and the d-axis stator current of the current control cycle to obtain the d-axis extended current of the current control cycle; obtaining the sum of the d-axis equivalent voltage generated by the d-axis equivalent current on the stator resistance of the motor and the d-axis stator voltage of the current control cycle to obtain the d-axis extended voltage of the current control cycle.

[0011] In some embodiments, the adaptive observer includes a first adaptive observer, and the speed estimation method for the sensorless permanent magnet synchronous motor further includes: acquiring the q-axis stator current and q-axis stator voltage of the motor in the current control cycle; inputting the d-axis extended current, d-axis extended voltage, q-axis stator current and q-axis stator voltage of the current control cycle to the first adaptive observer to obtain the estimated speed and rotor position of the motor in the current control cycle.

[0012] In some embodiments, reconstructing the d-axis stator current and d-axis stator voltage of the current control cycle based on the rotor flux linkage and the d-axis inductance of the motor in the current control cycle to obtain the d-axis extended current and d-axis extended voltage of the current control cycle includes: obtaining the sum of the d-axis equivalent current generated by the rotor flux linkage on the d-axis inductance and the d-axis stator current of the current control cycle to obtain the d-axis extended current of the current control cycle; obtaining the d-axis equivalent voltage generated by the d-axis equivalent current on the stator resistance of the motor, and obtaining the ratio of the sum of the d-axis equivalent voltage and the d-axis stator voltage of the current control cycle to the d-axis inductance to obtain the d-axis extended voltage of the current control cycle.

[0013] In some embodiments, the adaptive observer includes a second adaptive observer, and the speed estimation method for the sensorless permanent magnet synchronous motor further includes: acquiring the q-axis stator current and q-axis stator voltage of the motor in the current control cycle; reconstructing the q-axis stator voltage of the current control cycle based on the q-axis inductance to obtain the q-axis extended voltage of the current control cycle; and inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis extended voltage of the current control cycle to the second adaptive observer to obtain the speed estimate and rotor position estimate of the motor in the current control cycle.

[0014] In this embodiment, in addition to the rotor flux linkage ψ of the motor in the current control cycle f For the d-axis stator current i in the current control cycle d0 and d-axis stator voltage u d0 Reconstruct the data to obtain the d-axis extended current i′ of the current control cycle. d0 and d-axis extended voltage u′ d0 In addition, it is based on the q-axis inductance L q For the q-axis stator voltage u in the current control cycle q0 Perform reconstruction to obtain the q-axis extended voltage u′ of the current control cycle. q0 Then the second adaptive observer extends the current i′ along the d-axis based on the current control cycle. d0 d-axis extended voltage u′ d0 q-axis stator current i q0 and q-axis extended voltage u′ q0 Obtain the estimated speed of the motor in the current control cycle. and rotor position estimate Meanwhile, the second adaptive observer is also determined based on the voltage equations of the d-axis inductance and q-axis inductance of the motor, and can be applied to estimate the speed and rotor position of salient-pole permanent magnet synchronous motors and non-salient-pole permanent magnet synchronous motors.

[0015] In some embodiments, reconstructing the q-axis stator voltage of the current control cycle based on the q-axis inductance to obtain the q-axis extended voltage of the current control cycle includes: obtaining the ratio of the q-axis stator voltage of the current control cycle to the q-axis inductance to obtain the q-axis extended voltage of the current control cycle.

[0016] In some embodiments, the first adaptive observer includes a first state observer and an estimator. The step of inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis stator voltage of the current control cycle into the first adaptive observer to obtain the estimated speed and rotor position of the motor in the current control cycle includes: inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis stator voltage of the current control cycle into the first state observer to obtain a first difference between the d-axis extended current and the estimated d-axis extended current, and a second difference between the q-axis stator current and the estimated q-axis stator current; and inputting the first difference between the d-axis extended current and the estimated d-axis extended current, the second difference between the q-axis stator current and the estimated q-axis stator current, the d-axis extended current, and the q-axis stator current into the estimator to obtain the estimated speed and rotor position of the motor in the current control cycle.

[0017] In some embodiments, the step of inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis stator voltage of the current control cycle to the first state observer to obtain a first difference between the d-axis extended current and the estimated d-axis extended current, and a second difference between the q-axis stator current and the estimated q-axis stator current, includes: based on the d-axis extended voltage of the current control cycle, and the estimated d-axis extended current, speed, and q-axis stator current of the previous control cycle, the first difference between the d-axis extended current and the estimated d-axis extended current, and the second difference between the q-axis stator current and the estimated q-axis stator current. The difference is used to estimate the d-axis extended current estimate for the current control cycle, and a first difference between the d-axis extended current estimate and the d-axis extended current estimate for the current control cycle is obtained. Based on the q-axis stator voltage for the current control cycle, and the q-axis stator current estimate, speed estimate, d-axis extended current estimate, the first difference between the d-axis extended current estimates and the second difference between the q-axis stator current estimates for the previous control cycle, the q-axis stator current estimate for the current control cycle is estimated, and a second difference between the q-axis stator current estimates for the current control cycle is obtained.

[0018] This embodiment combines the parameters of the previous control cycle to estimate the d-axis extended current value for the current cycle. and q-axis stator current estimate This determines the deviation within the current control cycle, and based on this deviation, the deviation compensation is determined, ultimately yielding the closed-loop state equation, which ensures the tracking performance of the control system.

[0019] In some embodiments, the first state observer estimates the d-axis extended current estimate and the q-axis stator current estimate for the current control cycle in the following manner:

[0020] in, This is the estimated d-axis extended current value for the current control cycle. L is the estimated value of the q-axis stator current for the current control cycle. d Let L be the d-axis inductance. q Let u′ be the q-axis inductance. d0 The d-axis extended voltage of the current control cycle, u q0 R is the q-axis stator voltage of the current control cycle. s Let be the stator resistance of the motor. This is the estimated value of the d-axis extended current for the previous control cycle. This is the estimated value of the q-axis stator current for the previous control cycle. The estimated speed for the previous control cycle is ρ = L. q / L d g1 is the first gain coefficient, g2 is the second gain coefficient, and e id1 e is the first difference between the d-axis extended current of the previous control cycle and the estimated d-axis extended current. iq1 It is the second difference between the q-axis stator current of the previous control cycle and the estimated q-axis stator current.

[0021] In some embodiments, the second adaptive observer includes a second state observer and an estimator. The step of inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis extended voltage of the current control cycle to the second adaptive observer to obtain the estimated speed and rotor position of the motor in the current control cycle includes: inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis extended voltage of the current control cycle to the second state observer to obtain a first difference between the d-axis extended current and the estimated d-axis extended current, and a second difference between the q-axis stator current and the estimated q-axis stator current; and inputting the first difference between the d-axis extended current and the estimated d-axis extended current, the second difference between the q-axis stator current and the estimated q-axis stator current, the d-axis extended current, and the q-axis stator current to the estimator to obtain the estimated speed and rotor position of the motor in the current control cycle.

[0022] In some embodiments, the step of inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis extended voltage of the current control cycle to the second state observer to obtain a first difference between the d-axis extended current and the estimated d-axis extended current, and a second difference between the q-axis stator current and the estimated q-axis stator current, includes: based on the d-axis extended voltage of the current control cycle, and the estimated d-axis extended current, speed, and q-axis stator current of the previous control cycle, the first difference between the d-axis extended current and the estimated d-axis extended current, and the second difference between the q-axis stator current and the estimated q-axis stator current. The difference is used to estimate the d-axis extended current estimate for the current control cycle, and to obtain a first difference between the d-axis extended current estimate and the d-axis extended current estimate for the current control cycle. Based on the q-axis extended voltage for the current control cycle, and the q-axis stator current estimate, speed estimate, d-axis extended current estimate, the first difference between the d-axis extended current estimates, and the second difference between the q-axis stator current estimates for the previous control cycle, the q-axis stator current estimate for the current control cycle is estimated, and to obtain a second difference between the q-axis stator current estimates for the current control cycle.

[0023] This embodiment combines the parameters of the previous control cycle to estimate the d-axis extended current value for the current cycle. and q-axis stator current estimate This determines the deviation within the current control cycle, and based on this deviation, the deviation compensation is determined, ultimately yielding the closed-loop state equation, which ensures the tracking performance of the control system.

[0024] In some embodiments, the second state observer estimates the d-axis extended current estimate and the q-axis stator current estimate for the current control cycle in the following manner:

[0025] in, This is the estimated d-axis extended current value for the current control cycle. L is the estimated value of the q-axis stator current for the current control cycle. d Let L be the d-axis inductance. q Let u′ be the q-axis inductance. d0 The d-axis extended voltage of the current control cycle, u′ q0 R is the q-axis extended voltage of the current control cycle. s Let be the stator resistance of the motor. This is the estimated value of the d-axis extended current for the previous control cycle. This is the estimated value of the q-axis stator current for the previous control cycle. The estimated speed for the previous control cycle is ρ = L. q / L d g1 is the first gain coefficient, g2 is the second gain coefficient, and e id1 e is the first difference between the d-axis extended current of the previous control cycle and the estimated d-axis extended current. iq1 It is the second difference between the q-axis stator current of the previous control cycle and the estimated q-axis stator current.

[0026] In some embodiments, the step of inputting the first difference between the d-axis extended current and the estimated d-axis extended current, the second difference between the q-axis stator current and the estimated q-axis stator current, the d-axis extended current, and the q-axis stator current to the estimator to obtain the estimated speed and rotor position of the motor in the current control cycle includes: integrating the difference between the product of the d-axis extended current and the second difference between the q-axis stator current and the estimated q-axis stator current in the current control cycle and the product of the first difference between the q-axis stator current and the estimated d-axis extended current in the current control cycle to obtain the estimated speed in the current control cycle; integrating the estimated speed in the current control cycle to obtain the rotor position change in the current control cycle; and obtaining the rotor position change in the current control cycle and the estimated rotor position of the motor in the previous control cycle to obtain the estimated rotor position in the current control cycle.

[0027] Furthermore, this embodiment considers the unequal d-axis and q-axis inductances of the salient-pole permanent magnet synchronous motor, and selects variables for constructing the Lyapunov function, namely, based on the first difference e. id0The second difference e iq0 This is to accommodate the situation where the d-axis and q-axis of a salient-pole permanent magnet synchronous motor are not equal, thus satisfying the application requirements of both salient-pole and non-salient-pole permanent magnet synchronous motors.

[0028] Secondly, this application provides a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the above-described method for estimating the rotational speed of a sensorless permanent magnet synchronous motor.

[0029] Thirdly, this application proposes a speed estimation system for a sensorless permanent magnet synchronous motor, comprising: a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, it implements the aforementioned speed estimation method for a sensorless permanent magnet synchronous motor.

[0030] Fourthly, this application proposes a speed estimation device for a sensorless permanent magnet synchronous motor. The device includes: an acquisition module for acquiring the d-axis stator current and d-axis stator voltage of the motor in the current control cycle; an extension module for reconstructing the d-axis stator current and d-axis stator voltage of the motor in the current control cycle based on the rotor flux linkage and the d-axis inductance of the motor in the current control cycle to obtain the extended d-axis current and d-axis voltage of the current control cycle; and an adaptive observer for estimating the speed estimate and rotor position estimate of the motor in the current control cycle based on the extended d-axis current and d-axis voltage of the current control cycle. The adaptive observer is determined based on the voltage equation of the motor, which includes the d-axis inductance and q-axis inductance of the motor.

[0031] Fifthly, this application proposes an electrical device including the aforementioned sensorless permanent magnet synchronous motor speed estimation system, or the aforementioned sensorless permanent magnet synchronous motor speed estimation device.

[0032] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0033] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0034] Figure 1 is a flowchart of a speed estimation method for a sensorless permanent magnet synchronous motor according to some embodiments of this application;

[0035] Figure 2 is a schematic diagram of the control system of a sensorless permanent magnet synchronous motor according to some embodiments of this application;

[0036] Figure 3 is a schematic diagram of an adaptive observer according to some embodiments of this application;

[0037] Figure 4 is a block diagram of a speed estimation system for a sensorless permanent magnet synchronous motor according to some embodiments of this application;

[0038] Figure 5 is a block diagram of a speed estimation device for a sensorless permanent magnet synchronous motor according to some embodiments of this application;

[0039] Figure 6 is a block diagram of an electrical device according to some embodiments of this application;

[0040] Figure 7 is a block diagram of an electrical device according to some other embodiments of this application.

[0041] Figure label:

[0042] The system includes a speed estimation system 100 for a sensorless permanent magnet synchronous motor, a memory 110, a processor 120, a detection probe 130, a speed estimation device 200 for a sensorless permanent magnet synchronous motor, an acquisition module 210, an expansion module 220, an adaptive observer 230, and electrical equipment 1000. Detailed Implementation

[0043] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0045] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0046] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0047] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0048] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more (including two groups), and "multiple pieces" refers to two or more (including two pieces).

[0049] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0050] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0051] To ensure the operational stability of permanent magnet synchronous motors, it is necessary to monitor the motor speed and rotor position in real time during operation.

[0052] In one related technology, a tangent saturation function is used as the sliding surface control function of the flux linkage sliding mode observer, and the rotational speed and rotor position angle are obtained through a speed adaptive observation module based on Lyapunov functions. In another related technology, signal processing methods are used to digitally process the change process of the three-phase winding back electromotive force, extracting the position feature points of the back electromotive force during motor rotation. The rotor position information at these feature points is estimated using an extended Kalman filter, thereby obtaining the accurate rotor position.

[0053] Although the above technical solutions can estimate the speed and rotor position of the permanent magnet synchronous motor, they are based on salient pole permanent magnet synchronous motors and cannot be applied to salient pole permanent magnet synchronous motors. In addition, the above technical solutions are based on fourth-order state equations for data calculation in actual calculation, which involves a large amount of computation and is complex to implement.

[0054] To address the aforementioned technical problems, this application proposes a speed estimation method for a sensorless permanent magnet synchronous motor. During motor operation, the d-axis stator current and d-axis stator voltage of the motor in the current control cycle are acquired. Based on the rotor flux linkage and d-axis inductance of the motor in the current control cycle, the d-axis stator current and d-axis stator voltage of the current control cycle are reconstructed to obtain the extended d-axis current and d-axis voltage of the current control cycle. The extended d-axis current and d-axis voltage of the current control cycle are then input to an adaptive observer to obtain the estimated speed and rotor position of the motor in the current control cycle. The adaptive observer is determined based on the motor's voltage equation, which includes the motor's d-axis inductance and q-axis inductance.

[0055] In the technical solution of this application embodiment, during motor operation, the d-axis stator current and d-axis stator voltage of the motor in the current control cycle are acquired. Based on the rotor flux linkage and d-axis inductance of the motor in the current control cycle, the d-axis stator current and d-axis stator voltage of the current control cycle are reconstructed to obtain the d-axis extended current and d-axis extended voltage of the current control cycle. The d-axis extended current and d-axis extended voltage of the current control cycle are input to an adaptive observer to obtain the estimated speed and rotor position of the motor in the current control cycle. The adaptive observer is determined based on the voltage equation of the motor, which includes the d-axis inductance and q-axis inductance of the motor. Therefore, the adaptive observer is determined based on the voltage equation including the d-axis inductance and q-axis inductance of the motor, enabling this method to estimate the speed and rotor position of both salient-pole permanent magnet synchronous motors and non-salient-pole permanent magnet synchronous motors, expanding the applicability of the control method while ensuring the accuracy of the motor speed and rotor position estimation.

[0056] For ease of explanation, the following embodiments will be described with reference to FIG1 to illustrate the speed estimation method of the sensorless permanent magnet synchronous motor of this application.

[0057] Referring to Figure 1, the speed estimation method for a sensorless permanent magnet synchronous motor in this application may include the following steps:

[0058] S1, obtain the d-axis stator current i of the motor in the current control cycle. d0 and d-axis stator voltage u d0 ;

[0059] S2, based on the rotor flux linkage ψ of the motor in the current control cycle. f and the d-axis inductance L of the motor d For the d-axis stator current i in the current control cycle d0 and d-axis stator voltage u d0 Reconstruct the data to obtain the d-axis extended current i′ of the current control cycle. d0 and d-axis extended voltage u′ d0 ;

[0060] S3, extends the d-axis current i′ of the current control cycle. d0 and d-axis extended voltage u′ d0 The input is fed into the adaptive observer to obtain the estimated motor speed for the current control cycle. and rotor position estimate The adaptive observer is determined based on the motor's voltage equation, which includes the motor's d-axis inductance L. d and q-axis inductance L q .

[0061] Referring to Figure 2, during the control process of the permanent magnet synchronous motor, the three-phase current i of the permanent magnet synchronous motor is sampled and acquired. a i b i c The d-axis stator current i is obtained after Park transformation. d and q-axis stator current i q Then, at the given rotation speed Compared with the estimated speed The difference is used to obtain the reference torque T through the speed regulator. ref And according to the reference torque T ref Bus voltage U dc and speed estimate The d-axis reference current is obtained by combining maximum torque-to-current ratio control and field weakening control. and q-axis reference current d-axis reference current and d-axis stator current i dThe difference is input to the d-axis current regulator to obtain the d-axis stator voltage u. d and the q-axis reference current and q-axis stator current i q The difference is input to the q-axis current regulator to obtain the q-axis stator voltage u. q The d-axis stator voltage u d and q-axis stator voltage u q After rotational transformation, the signal is input to the modulation module, which generates a PWM (Pulse Width Modulation) signal. The inverter then converts the received PWM signal into a three-phase current to control the operation of the permanent magnet synchronous motor.

[0062] In this embodiment of the application, the d-axis stator current i of the current control cycle obtained through the Park transformation is... d0 The reconstructed d-axis extended current i′ of the current control cycle is obtained. d0 The d-axis stator voltage u d0 The d-axis extended voltage u′ of the current control cycle is obtained through reconstruction. d0 Then extend the d-axis current i′ of the current control cycle. d0 and d-axis extended voltage u′ d0 The input is an adaptive observer, which derives an adaptive law for estimating the rotational speed based on Lyapunov's stability theorem, and uses the received d-axis extended current i′ from the current control cycle. d0 and d-axis extended voltage u′ d0 This allows us to calculate the estimated motor speed during the current control cycle. and rotor position estimate Speed ​​estimate for the current control cycle and rotor position estimate Used for motor control, for example, given a speed. Compared with the estimated speed The difference is used to obtain the reference torque T through the speed regulator. ref Rotor position estimate Used for d-axis stator voltage u d and q-axis stator voltage u q Rotational transformation, rotor position estimate For three-phase current i a i b i c The Park transformation. In the synchronous rotating coordinate system, the voltage equation of an ideal permanent magnet synchronous motor is: resistance voltage drop + magnetic field voltage drop + back electromotive force, as shown in formulas (1) and (2).

[0063] Among them, ud For d-axis stator voltage, R s For stator resistance, i d L is the d-axis stator current. d For the d-axis inductance, ω r L is the rotor electric angular velocity. q For q-axis inductance, i q U is the q-axis stator current. q Let ψ be the q-axis stator voltage. f For rotor flux linkage.

[0064] In the above formulas (1) and (2), L is respectively used as d L represents the d-axis inductance. q Let L represent the q-axis inductance; therefore, the voltage equations already reflect the differences between salient-pole and non-salient-pole permanent magnet synchronous motors. Specifically, when L... d equal to L q When L represents the voltage equation of a salient-pole permanent magnet synchronous motor; when L d Not equal to L q When, the voltage equation represents the voltage of the salient pole permanent magnet synchronous motor.

[0065] The adaptive observer is determined based on formulas (1) and (2) to make it applicable to the speed estimation of salient-pole permanent magnet synchronous motors and non-salient-pole permanent magnet synchronous motors. and rotor position estimate The determination of this value can be used to estimate the speed and rotor position of salient-pole permanent magnet synchronous motors and non-salient-pole permanent magnet synchronous motors.

[0066] According to some embodiments of this application, based on the rotor flux linkage ψ of the motor in the current control cycle... f and the d-axis inductance L of the motor d For the d-axis stator current i in the current control cycle d0 and d-axis stator voltage u d0 Reconstruct the data to obtain the d-axis extended current i′ of the current control cycle. d0 and d-axis extended voltage u′ d0 This includes: obtaining the rotor flux linkage ψ f Inductance L along the d-axis d The d-axis equivalent current generated on The d-axis stator current i of the current control cycle d0 The sum of these two values ​​yields the d-axis extended current i′ for the current control cycle. d0 Obtain the d-axis equivalent current. In the stator resistance R of the motor s The d-axis equivalent voltage generated on The d-axis stator voltage u of the current control cycle d0 The sum of these values ​​yields the d-axis extended voltage u′ for the current control cycle.d0 Specifically, the d-axis extended current i′ of the current control cycle d0 The calculation formula is as follows:

[0067] Where, i′ d0 This is the d-axis extended current for the current control cycle. i is the d-axis equivalent current generated by the rotor flux linkage on the d-axis inductance. d0 This represents the d-axis stator current during the current control cycle.

[0068] d-axis extended voltage u′ in the current control cycle d0 The calculation formula is as follows:

[0069] Where, u′ d0 For the d-axis extended voltage of the current control cycle, u d0 The d-axis stator voltage for the current control cycle. The d-axis equivalent voltage is generated across the stator resistance of the motor by the d-axis equivalent current.

[0070] According to some embodiments of this application, the adaptive observer includes a first adaptive observer, and the speed estimation method for a sensorless permanent magnet synchronous motor further includes: obtaining the q-axis stator current i of the motor in the current control cycle. q0 and q-axis stator voltage u q0 ; Extend the d-axis current i′ of the current control cycle d0 d-axis extended voltage u′ d0 q-axis stator current i q0 and q-axis stator voltage u q0 The input is fed into the first adaptive observer to obtain the estimated motor speed in the current control cycle. and rotor position estimate

[0071] Specifically, the input to the first adaptive observer is the d-axis extended current i′ of the current control cycle. d0 d-axis extended voltage u′ d0 q-axis stator current i q0 and q-axis stator voltage u q0 The first adaptive observer is based on the d-axis extended current i′ of the current control cycle. d0 d-axis extended voltage u′ d0 q-axis stator current i q0 and q-axis stator voltage u q0 By observing and estimating the motor system, the estimated speed value for the current control cycle can be obtained. and rotor position estimate Speed ​​estimate for the current control cycle and rotor position estimate Used for motor control.

[0072] According to some embodiments of this application, based on the rotor flux linkage ψ of the motor in the current control cycle... f and the d-axis inductance L of the motor d For the d-axis stator current i in the current control cycle d0 and d-axis stator voltage u d0 Reconstruct the data to obtain the d-axis extended current i′ of the current control cycle. d0 and d-axis extended voltage u′ d0 This includes: obtaining the rotor flux linkage ψ f Inductance L along the d-axis d The d-axis equivalent current generated on The d-axis stator current i of the current control cycle d0 The sum of these two values ​​yields the d-axis extended current i′ for the current control cycle. d0 Obtain the d-axis equivalent current. In the stator resistance R of the motor s The d-axis equivalent voltage generated on And obtain the d-axis equivalent voltage The d-axis stator voltage u of the current control cycle d0 The sum of the d-axis inductance L d The ratio of the two values ​​is used to obtain the d-axis extended voltage u′ of the current control cycle. d0 .

[0073] Specifically, the d-axis extended current i′ of the current control cycle d0 The calculation formula is formula (3), and the d-axis extended voltage u′ of the current control cycle. d0 The calculation formula is:

[0074] Where, u′ d0 For the d-axis extended voltage of the current control cycle, u d0 L is the d-axis stator voltage. d R is the d-axis inductance. s For stator resistance, ψ f For rotor flux linkage.

[0075] This embodiment uses As a calculation coefficient, the d-axis extended voltage u′ of the current control cycle is obtained through formula (5). d0 The d-axis extended voltage u′ of the current control cycle obtained using formula (4) is relative to the voltage obtained using formula (4). d0 This can reduce the amount of computation within the adaptive observer.

[0076] According to some embodiments of this application, the adaptive observer includes a second adaptive observer, and the speed estimation method for a sensorless permanent magnet synchronous motor further includes: obtaining the q-axis stator current i of the motor in the current control cycle. q0 and q-axis stator voltage u q0 Based on q-axis inductance L q For the q-axis stator voltage u in the current control cycle q0 Reconstruct the data to obtain the q-axis extended voltage u′ for the current control cycle. q0 ; Extend the d-axis current i′ of the current control cycle d0 d-axis extended voltage u′ d0 q-axis stator current i q0 and q-axis extended voltage u′ q0 The input is fed into the second adaptive observer to obtain the estimated motor speed for the current control cycle. and rotor position estimate

[0077] In this embodiment, in addition to the rotor flux linkage ψ of the motor in the current control cycle f and d-axis inductance L d For the d-axis stator current i in the current control cycle d0 and d-axis stator voltage u d0 Reconstruct the data to obtain the d-axis extended current i′ of the current control cycle. d0 and d-axis extended voltage u′ d0 In addition, it is based on the q-axis inductance L q For the q-axis stator voltage u in the current control cycle q0 Perform reconstruction to obtain the q-axis extended voltage u′ of the current control cycle. q0 Then the second adaptive observer extends the current i′ along the d-axis based on the current control cycle. d0 d-axis extended voltage u′ d0 q-axis stator current i q0 and q-axis extended voltage u′ q0 The motor system is observed, and the estimated speed of the motor in the current control cycle is obtained. and rotor position estimate

[0078] The second adaptive observer is also determined based on the motor voltage equations of the above formulas (1) and (2), thus making it suitable for estimating the speed and rotor position of salient-pole permanent magnet synchronous motors and non-salient-pole permanent magnet synchronous motors.

[0079] According to some embodiments of this application, based on the q-axis inductor L q For the q-axis stator voltage u in the current control cycle d0Reconstruct the data to obtain the q-axis extended voltage u′ for the current control cycle. q0 This includes: obtaining the q-axis stator voltage u of the current control cycle. q0 With q-axis inductance L q The ratio of these values ​​yields the q-axis extended voltage u′ for the current control cycle. q0 .

[0080] In other words, the q-axis extended voltage u′ of the current control cycle q0 The calculation formula is:

[0081] Where, u′ q0 For the q-axis extended voltage of the current control cycle, u q0 L is the q-axis stator voltage for the current control cycle. q It is the q-axis inductance.

[0082] Due to the use of vector control, the rotor flux linkage ψ f With the q-axis component being 0, and the rotor flux linkage having the d-axis component, the rotor flux linkage ψ will be affected. f An induced electromotive force is generated along the d-axis. Therefore, this embodiment is based on the rotor flux linkage ψ. f Constructing current state variables can take into account the influence of rotor flux linkage changes. Furthermore, since the q-axis component of the rotor flux linkage is zero, the q-axis current remains unchanged, and the q-axis voltage is also multiplied by a coefficient.

[0083] In this embodiment, the d-axis extended current i′ of the current control cycle is calculated using formula (3). d0 The d-axis extended voltage u′ of the current control cycle is calculated using formula (5). d0 The q-axis extended voltage u′ of the current control cycle is calculated using formula (6). q0 The second adaptive observer is based on the q-axis stator current i q0 and the reconstructed d-axis extended current i′ d0 d-axis extended voltage u′ d0 q-axis extended voltage u′ q0 This yields an estimated speed of the motor during the current control cycle. and rotor position estimate

[0084] According to some embodiments of this application, the first adaptive observer includes a first state observer and an estimator, which extends the d-axis current i′ of the current control cycle. d0 d-axis extended voltage u′ d0 q-axis stator current i q0 and q-axis stator voltage u q0The input is fed into the first adaptive observer to obtain the estimated motor speed in the current control cycle. and rotor position estimate This includes: extending the d-axis current i′ of the current control cycle. d0 d-axis extended voltage u′ d0 q-axis stator current i q0 and q-axis stator voltage u q0 The input is fed into the first state observer to obtain the d-axis extended current i′ of the current control cycle. d0 With d-axis extended current estimate The first difference e between id0 and the q-axis stator current i q0 q-axis stator current estimate The second difference e between iq0 The d-axis extended current i′ of the current control cycle will be increased. d0 With d-axis extended current estimate The first difference e between id0 q-axis stator current i q0 q-axis stator current estimate The second difference e between iq0 d-axis extended current i′ d0 and q-axis stator current i q0 The input is fed into the estimator to obtain the estimated motor speed for the current control cycle. and rotor position estimate

[0085] Specifically, the first state observer is based on the d-axis extended current i′ of the current control cycle. d0 d-axis extended voltage u′ d0 q-axis stator current i q0 and q-axis stator voltage u q0 First, the d-axis stator current of the current control cycle is estimated to determine the estimated value of the d-axis extended current for the current control cycle. The q-axis stator current of the current control cycle is estimated to determine the estimated value of the q-axis stator current. Then the d-axis extended current i′ of the current control cycle is... d0 With d-axis extended current estimate The first difference e is obtained by subtracting the two values. id0 , the q-axis stator current i q0 q-axis stator current estimate The difference is used to obtain the second difference e. iq0 The first difference e id0 The second difference e iq0This represents the deviation for the current control cycle. The estimator extends the current i′ along the d-axis based on the current control cycle. d0 With d-axis extended current estimate The first difference e between id0 q-axis stator current i q0 q-axis stator current estimate The second difference e between iq0 d-axis extended current i′ d0 and q-axis stator current i q0 The motor speed and rotor position are determined in the current control cycle.

[0086] In this embodiment, the estimator is based on the deviation of the current control cycle and the d-axis extended current i′. d0 and q-axis stator current i q0 This is used to estimate the speed and rotor position in the current control cycle, thus obtaining an estimated value of the motor speed in the current control cycle. and rotor position estimate

[0087] In this application, the d-axis extended current estimate for the current control cycle is... and q-axis stator current estimate The determination method is based on the voltage equation of the permanent magnet synchronous motor. The following is the estimated value of the d-axis extended current for the current control cycle. and q-axis stator current estimate The method for determining it will be explained in detail.

[0088] For formula (1), after formula transformation, we can obtain:

[0089] According to formula (3), we can obtain:

[0090] According to formula (4), we can obtain:

[0091] Substituting formulas (8) and (9) into formula (7) yields:

[0092] The formula (10) is transformed as follows:

[0093] Simplifying formula (11) yields:

[0094] According to the differentiation rule, the derivative of a constant is equal to zero, i.e., the formula... Therefore, formula (12) can be converted to:

[0095] As for formula (2), after formula transformation, we can obtain:

[0096] Substituting formula (8) into formula (14), we get:

[0097] By transforming formula (15), we get:

[0098] Therefore, by transforming the above formulas, the two-order state equations (13) and (18) in the synchronous rotating coordinate system are obtained from the voltage equation of the permanent magnet synchronous motor.

[0099] During application, the d-axis extended current i′ of the current control cycle can be... d0 d-axis extended voltage u′ d0 q-axis stator current i q0 Input the result into formula (13) and integrate the result to obtain the estimated value of the d-axis extended current for the current control cycle. Then extend the d-axis current i′ d0 With d-axis extended current estimate The difference is used to obtain the first difference e of the current control cycle. id0 .

[0100] At the same time, the d-axis extended current i′ of the current control cycle will be... d0 q-axis stator current i q0 and q-axis stator voltage u q0 Substituting into formula (18) and integrating the calculation results, we obtain the estimated value of the q-axis stator current. Then the q-axis stator current i q0 q-axis stator current estimate The difference is used to obtain the second difference e. iq0 .

[0101] The estimator is based on the first difference e of the current control cycle. id0 The second difference e iq0 and d-axis extended current i′ d0 and q-axis stator current i q0 This is used to estimate the speed and rotor position in the current control cycle, thus obtaining an estimated value of the motor speed in the current control cycle. and rotor position estimate

[0102] Referring to Figure 3, according to some embodiments of this application, the d-axis extended current i′ of the current control cycle is... d0 d-axis extended voltage u′ d0 q-axis stator current iq0 and q-axis stator voltage u q0 The input is fed into the first state observer to obtain the d-axis extended current i′ of the current control cycle. d0 With d-axis extended current estimate The first difference e between id0 and the q-axis stator current i q0 q-axis stator current estimate The second difference e between iq0 This includes: the d-axis extended voltage u′ based on the current control cycle. d0 And the estimated d-axis extended current value of the previous control cycle. Speed ​​estimate q-axis stator current estimate d-axis extended current i′ d1 With d-axis extended current estimate The first difference e between id1 and q-axis stator current i q1 q-axis stator current estimate The second difference e between iq1 The estimated value of the d-axis extended current for the current control cycle is obtained. And obtain the d-axis extended current i′ of the current control cycle. d0 With d-axis extended current estimate The first difference e between id0 Based on the q-axis stator voltage u of the current control cycle q0 and the estimated q-axis stator current value of the previous control cycle. Speed ​​estimate d-axis extended current estimate d-axis extended current i′ d1 With d-axis extended current estimate The first difference e between id1 and q-axis stator current i q1 q-axis stator current estimate The second difference e between iq1 The estimated value of the q-axis stator current for the current control cycle is obtained. And obtain the q-axis stator current i in the current control cycle. q0 q-axis stator current estimate The second difference e between iq0 .

[0103] To ensure the tracking performance of the control system, this embodiment uses parameters from the previous control cycle to estimate the d-axis extended current for the current cycle. and q-axis stator current estimate This determines the deviation within the current control cycle. Based on this deviation, the deviation compensation is then determined, ultimately yielding the closed-loop state equation.

[0104] According to some embodiments of this application, the first state observer estimates the d-axis extended current estimate for the current control cycle in the following manner. and q-axis stator current estimates

[0105] in, This is the estimated d-axis extended current value for the current control cycle. L is the estimated q-axis stator current for the current control cycle. d For the d-axis inductance, L q U′ is the q-axis inductance. d0 For the d-axis extended voltage of the current control cycle, u q0 R is the q-axis stator voltage for the current control cycle. s This is the stator resistance of the motor. This is the estimated value of the d-axis extended current from the previous control cycle. This is the estimated value of the q-axis stator current from the previous control cycle. The speed estimate for the previous control cycle is ρ = L. q / L d g1 is the first gain coefficient, g2 is the second gain coefficient, and e id1 The d-axis extended current i′ of the previous control cycle d1 With d-axis extended current estimate The first difference between them, e iq1 The q-axis stator current i in the previous control cycle q1 q-axis stator current estimate The second difference between them.

[0106] Specifically, in the process of speed estimation for a permanent magnet synchronous motor, the d-axis stator current i in the current control cycle is first determined. d0 d-axis stator voltage u d0 q-axis stator current i q0 and q-axis stator voltage u q0 Then, for the d-axis stator current i in the current control cycle d0 and d-axis stator voltage u d0 Reconstruct the data to obtain the d-axis extended current i′ of the current control cycle. d0 and d-axis extended voltage u′ d0 The d-axis extended current i′ of the current control cycle will be increased. d0 d-axis extended voltage u′ d0 q-axis stator current i q0and q-axis stator voltage u q0 The input is fed into the first adaptive observer, and then combined with the parameters of the previous control cycle, and substituted into formulas (19) and (20) to calculate the d-axis extended current estimate for the current control cycle. q-axis stator current estimate for the current control cycle And further calculate the first difference e for this control cycle. id0 The second difference e iq0 Then, based on the first difference e of the current control cycle id0 The second difference e iq0 d-axis extended current i′ d0 and q-axis stator current i q0 The estimated speed of the motor in the current control cycle is calculated. and rotor position estimate

[0107] According to some embodiments of this application, the second adaptive observer includes a second state observer and an estimator, which extends the d-axis current i′ of the current control cycle. d0 d-axis extended voltage u′ d0 q-axis stator current i q0 and q-axis extended voltage u′ q0 The input is fed into the second adaptive observer to obtain the estimated motor speed for the current control cycle. and rotor position estimate This includes: extending the d-axis current i′ of the current control cycle. d0 d-axis extended voltage u′ d0 q-axis stator current i q0 and q-axis extended voltage u′ q0 The input is fed into the second state observer to obtain the d-axis extended current i′ of the current control cycle. d0 With d-axis extended current estimate The first difference e between id0 and the q-axis stator current i q0 q-axis stator current estimate The second difference e between iq0 ; Extend the d-axis current i′ of the current control cycle d0 With d-axis extended current estimate The first difference e between id0 q-axis stator current i q0 q-axis stator current estimate The second difference e between iq0 d-axis extended current i′ d0 and q-axis stator current i q0The input is fed into the estimator to obtain the estimated motor speed for the current control cycle. and rotor position estimate

[0108] In other words, the second state observer is based on the d-axis extended current i′ of the current control cycle. d0 d-axis extended voltage u′ d0 q-axis stator current i q0 and q-axis extended voltage u′ q0 First, the d-axis stator current of the current control cycle is estimated to determine the estimated value of the d-axis extended current of the current control cycle. The q-axis stator current of the current control cycle is estimated to determine the estimated value of the q-axis stator current. Then the d-axis extended current i′ of the current control cycle is... d0 With d-axis extended current estimate The first difference e is obtained by subtracting the two values. id0 , the q-axis stator current i q0 q-axis stator current estimate The difference is used to obtain the second difference e. iq0 d-axis extended current i′ d0 With d-axis extended current estimate The first difference e between id0 q-axis stator current i q0 q-axis stator current estimate The second difference e between iq0 This represents the deviation for the current control cycle. The estimator calculates the deviation based on the current control cycle deviation and the d-axis extended current i′. d0 and q-axis stator current i q0 This is used to estimate the speed and rotor position in the current control cycle, thus obtaining an estimated value of the motor speed in the current control cycle. and rotor position estimate

[0109] Furthermore, according to formula (6), we can transform it to obtain:

[0110] u q =L q u′ q (twenty one)

[0111] Substituting formulas (21) and (8) into formula (14), we get:

[0112] Transform formula (22) as follows:

[0113] Therefore, in this embodiment, the two-order state equations (13) and (25) in the synchronous rotating coordinate system are obtained from the voltage equation of the permanent magnet synchronous motor.

[0114] During application, the d-axis extended current i′ of the current control cycle will be... d0 d-axis extended voltage u′ d0 q-axis stator current i q0 Input the result into formula (13) and integrate the result to obtain the estimated value of the d-axis extended current for the current control cycle. Then extend the d-axis current i′ d0 With d-axis extended current estimate The difference is used to obtain the first difference e of the current control cycle. id0 .

[0115] At the same time, the d-axis extended current i′ of the current control cycle will be... d0 q-axis stator current i q0 and q-axis extended voltage u′ q0 Substituting into formula (25) and integrating the calculation results, we obtain the estimated value of the q-axis stator current. Then the q-axis stator current i q0 q-axis stator current estimate The difference is used to obtain the second difference e. iq0 .

[0116] The estimator is based on the first difference e of the current control cycle. id0 The second difference e iq0 and d-axis extended current i′ d0 and q-axis stator current i q0 This is used to estimate the speed and rotor position in the current control cycle, thus obtaining an estimated value of the motor speed in the current control cycle. and rotor position estimate

[0117] According to some embodiments of this application, the d-axis extended current i′ of the current control cycle is... d0 d-axis extended voltage u′ d0 q-axis stator current i q0 and q-axis extended voltage u′ q0 The input is fed into the second state observer to obtain the d-axis extended current i′ of the current control cycle. d0 With d-axis extended current estimate The first difference e between id0 and the q-axis stator current i q0 q-axis stator current estimate The second difference e between iq0 This includes: the d-axis extended voltage u′ based on the current control cycle.d0 And the estimated d-axis extended current value of the previous control cycle. Speed ​​estimate q-axis stator current estimate d-axis extended current i′ d1 With d-axis extended current estimate The first difference e between id1 and q-axis stator current i q1 q-axis stator current estimate The second difference e between iq1 The estimated value of the d-axis extended current for the current control cycle is obtained. And obtain the d-axis extended current i′ of the current control cycle. d0 With d-axis extended current estimate The first difference e between id0 Based on the q-axis extended voltage u′ of the current control cycle q0 and the estimated q-axis stator current value of the previous control cycle. Speed ​​estimate d-axis extended current estimate d-axis extended current i′ d1 With d-axis extended current estimate The first difference e between id1 and q-axis stator current i q1 q-axis stator current estimate The second difference e between iq1 The estimated value of the q-axis stator current for the current control cycle is obtained. And obtain the q-axis stator current i in the current control cycle. q0 q-axis stator current estimate The second difference e between iq0 .

[0118] To ensure the tracking performance of the control system, this embodiment uses parameters from the previous control cycle to estimate the d-axis extended current for the current cycle. and q-axis stator current estimate This determines the deviation within the current control cycle, and based on this deviation, the deviation compensation is determined, ultimately yielding the closed-loop state equation.

[0119] According to some embodiments of this application, the second state observer estimates the d-axis extended current estimate for the current control cycle in the following manner. and q-axis stator current estimates

[0120] in, This is the estimated d-axis extended current value for the current control cycle. L is the estimated q-axis stator current for the current control cycle. d For the d-axis inductance, L q U′ is the q-axis inductance. d0 For the d-axis extended voltage of the current control cycle, u′ d0 R is the q-axis extended voltage for the current control cycle. s This is the stator resistance of the motor. This is the estimated value of the d-axis extended current from the previous control cycle. This is the estimated value of the q-axis stator current from the previous control cycle. The speed estimate for the previous control cycle is ρ = L. q / L d g1 is the first gain coefficient, g2 is the second gain coefficient, and e id1 The d-axis extended current i′ of the previous control cycle d1 With d-axis extended current estimate The first difference between them, e iq1 The q-axis stator current i in the previous control cycle q1 q-axis stator current estimate The second difference between them.

[0121] In this embodiment, during the speed estimation of the permanent magnet synchronous motor, the d-axis stator current i of the current control cycle is first obtained. d0 d-axis stator voltage u d0 q-axis stator current i q0 and q-axis stator voltage u q0 Then, for the d-axis stator current i in the current control cycle d0 and d-axis stator voltage u d0 Reconstruct the data to obtain the d-axis extended current i′ of the current control cycle. d0 and d-axis extended voltage u′ d0 And for the q-axis stator voltage u of the current control cycle q0 Reconstruct the data to obtain the q-axis extended voltage u′ for the current control cycle. q0 The d-axis extended current i′ of the current control cycle will be increased. d0 d-axis extended voltage u′ d0 q-axis stator current i q0 and q-axis stator voltage u q0 The input is fed into the second adaptive observer, and then, combined with the parameters from the previous control cycle, it is substituted into formulas (26) and (27) to calculate the d-axis extended current estimate for the current control cycle. q-axis stator current estimate for the current control cycle Furthermore, the d-axis extended current i′ for this control cycle is calculated. d0 With d-axis extended current estimate The first difference e between id0 q-axis stator current i q0 q-axis stator current estimate The second difference e between iq0 Then, based on the d-axis extended current i′ of the current control cycle d0 With d-axis extended current estimate The first difference e between id0 q-axis stator current i q0 q-axis stator current estimate The second difference e between iq0 d-axis extended current i′ d0 and q-axis stator current i q0 The estimated speed of the motor in the current control cycle is calculated. and rotor position estimate

[0122] According to some embodiments of this application, the d-axis extended current i′ of the current control cycle is... d0 With d-axis extended current estimate The first difference e between ′d0 q-axis stator current i q0 q-axis stator current estimate The second difference e between iq0 d-axis extended current i′ d0 and q-axis stator current i q0 The input is fed into the estimator to obtain the estimated motor speed for the current control cycle. and rotor position estimate Includes: the d-axis extended current i′ for the current control cycle d0 and q-axis stator current i q0 q-axis stator current estimate The second difference e between iq0 The product of the current control cycle's q-axis stator current i q0 and d-axis extended current i′ d0 With d-axis extended current estimate The first difference e between id0 Integrating the product and the difference between them, we obtain the speed estimate for the current control cycle. Speed ​​estimate for the current control cycle Integrate to obtain the rotor position change in the current control cycle, and obtain the rotor position change in the current control cycle and the estimated rotor position θ0 of the motor in the previous control cycle to obtain the estimated rotor position for the current control cycle.

[0123] Specifically, the function formula is determined based on Lyapunov's stability theorem:

[0124] in, ρ=L q / L d .

[0125] According to Lyapunov's stability theorem, when When the system is asymptotically stable over a wide range, the adaptive law for estimating the rotational speed is obtained:

[0126] or

[0127] For example, it can be Unfold, when When, if the conditions are met The adaptive law for determining the estimated rotational speed is then given by formula (29).

[0128] When the adaptive law for estimating the rotational speed is adopted using formula (29), the estimated rotational speed for the current control cycle can be obtained. The calculation formula is:

[0129] in, i′ is the estimated speed for the current control cycle. d0 e is the d-axis extended current for the current control cycle. iq0 The q-axis stator current i in the current control cycle q0 q-axis stator current estimate The second difference between them, i q0 e is the q-axis stator current in the current control cycle. id0 The d-axis extended current i′ for the current control cycle d0 With d-axis extended current estimate The first difference between them.

[0130] The formula for calculating the rotor position estimate is:

[0131] in, This is the estimated rotor position for the current cycle. θ0 is the estimated rotational speed for the current control cycle, and θ0 is the estimated rotor position for the previous control cycle.

[0132] This embodiment uses second-order state equations to estimate the rotational speed of the permanent magnet synchronous motor during the current control cycle. And further from the speed estimate Calculate the rotor position estimate

[0133] Furthermore, this embodiment considers the unequal d-axis and q-axis inductances of the salient-pole permanent magnet synchronous motor, and selects variables for constructing the Lyapunov function, namely, based on the first difference e. id0 The second difference e iq0 This paper considers the case where the d-axis and q-axis of a salient-pole permanent magnet synchronous motor are not equal, thus satisfying the application requirements of both salient-pole and non-salient-pole permanent magnet synchronous motors. Furthermore, the speed estimation method disclosed in this application reduces the order of the state equations, simplifying programming and significantly reducing computational load.

[0134] Corresponding to the above embodiments, this application also proposes a computer-readable storage medium.

[0135] The computer-readable storage medium of this application embodiment stores a program that, when executed by a processor, implements the above-described method for estimating the rotational speed of a sensorless permanent magnet synchronous motor.

[0136] Corresponding to the above embodiments, this application also proposes a speed estimation system for a sensorless permanent magnet synchronous motor.

[0137] Referring to FIG4, the speed estimation system 100 for a sensorless permanent magnet synchronous motor of this application includes: a memory 110, a processor 120, and a program stored in the memory 110 and executable on the processor 120. When the processor 120 executes the program, it implements the speed estimation method for the sensorless permanent magnet synchronous motor described above.

[0138] Corresponding to the above embodiments, this application also proposes a speed estimation device for a sensorless permanent magnet synchronous motor.

[0139] Referring to Figure 5, the speed estimation device 200 for a sensorless permanent magnet synchronous motor of this application includes: an acquisition module 210, an extension module 220, and an adaptive observer 230. The acquisition module 210 acquires the d-axis stator current and d-axis stator voltage of the motor in the current control cycle. The extension module 220 reconstructs the d-axis stator current and d-axis stator voltage of the motor in the current control cycle based on the rotor flux linkage and the motor's d-axis inductance to obtain the extended d-axis current and d-axis voltage of the current control cycle. The adaptive observer 230 estimates the estimated speed and rotor position of the motor in the current control cycle based on the extended d-axis current and d-axis voltage; wherein the adaptive observer 230 is determined based on the motor's voltage equation, which includes the motor's d-axis inductance and q-axis inductance.

[0140] Corresponding to the above embodiments, this application also proposes an electrical device.

[0141] Referring to FIG6, the electrical device 1000 of this application includes the speed estimation system 100 of the sensorless permanent magnet synchronous motor described above, or, as shown in FIG7, the electrical device 1000 of this application includes the speed estimation device 200 of the sensorless permanent magnet synchronous motor.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for estimating the rotational speed of a sensorless permanent magnet synchronous motor, characterized by, The method includes: Obtain the d-axis stator current and d-axis stator voltage of the motor in the current control cycle; Based on the rotor flux linkage and d-axis inductance of the motor in the current control cycle, the d-axis stator current and d-axis stator voltage of the current control cycle are reconstructed to obtain the d-axis extended current and d-axis extended voltage of the current control cycle. The d-axis extended current and d-axis extended voltage of the current control cycle are input to the adaptive observer to obtain the estimated speed and rotor position of the motor in the current control cycle; wherein, the adaptive observer is determined based on the voltage equation of the motor, the voltage equation including the d-axis inductance and q-axis inductance of the motor.

2. The method of claim 1, wherein, The process of reconstructing the d-axis stator current and d-axis stator voltage of the current control cycle based on the rotor flux linkage and d-axis inductance of the motor in the current control cycle to obtain the d-axis extended current and d-axis extended voltage of the current control cycle includes: The sum of the d-axis equivalent current generated by the rotor flux on the d-axis inductor and the d-axis stator current of the current control cycle is obtained to obtain the d-axis extended current of the current control cycle. The sum of the d-axis equivalent voltage generated by the d-axis equivalent current on the stator resistance of the motor and the d-axis stator voltage of the current control cycle is obtained to obtain the d-axis extended voltage of the current control cycle.

3. The method of claim 2, wherein, The adaptive observer includes a first adaptive observer, and the method further includes: Obtain the q-axis stator current and q-axis stator voltage of the motor in the current control cycle; The d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis stator voltage of the current control cycle are input to the first adaptive observer to obtain the estimated speed and rotor position of the motor in the current control cycle.

4. The method of claim 1, wherein, The process of reconstructing the d-axis stator current and d-axis stator voltage of the current control cycle based on the rotor flux linkage and d-axis inductance of the motor in the current control cycle to obtain the d-axis extended current and d-axis extended voltage of the current control cycle includes: The sum of the d-axis equivalent current generated by the rotor flux on the d-axis inductor and the d-axis stator current of the current control cycle is obtained to obtain the d-axis extended current of the current control cycle. The d-axis equivalent voltage generated by the d-axis equivalent current on the stator resistance of the motor is obtained, and the ratio of the sum of the d-axis equivalent voltage and the d-axis stator voltage of the current control cycle to the d-axis inductance is obtained to obtain the d-axis extended voltage of the current control cycle.

5. The method of claim 4, wherein, The adaptive observer includes a second adaptive observer, and the method further includes: Obtain the q-axis stator current and q-axis stator voltage of the motor in the current control cycle; Based on the q-axis inductance, the q-axis stator voltage of the current control cycle is reconstructed to obtain the q-axis extended voltage of the current control cycle; The d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis extended voltage of the current control cycle are input to the second adaptive observer to obtain the estimated speed and rotor position of the motor in the current control cycle.

6. The method of claim 5, wherein, The reconstructing of the q-axis stator voltage of the current control cycle based on the q-axis inductance to obtain the q-axis extended voltage of the current control cycle includes: The ratio of the q-axis stator voltage to the q-axis inductance in the current control cycle is obtained to obtain the q-axis extended voltage in the current control cycle.

7. The method of claim 3, wherein, The first adaptive observer includes a first state observer and an estimator. The step of inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis stator voltage of the current control cycle into the first adaptive observer to obtain the estimated speed and rotor position of the motor in the current control cycle includes: The d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis stator voltage of the current control cycle are input to the first state observer to obtain the first difference between the d-axis extended current and the estimated value of the d-axis extended current, and the second difference between the q-axis stator current and the estimated value of the q-axis stator current. The first difference between the d-axis extended current and the estimated d-axis extended current in the current control cycle, the second difference between the q-axis stator current and the estimated q-axis stator current, the d-axis extended current, and the q-axis stator current are input to the estimator to obtain the estimated speed and rotor position of the motor in the current control cycle.

8. The method of claim 7, wherein, The step of inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis stator voltage of the current control cycle to the first state observer to obtain a first difference between the d-axis extended current and the estimated d-axis extended current, and a second difference between the q-axis stator current and the estimated q-axis stator current, includes: Based on the d-axis extended voltage of the current control cycle, and the estimated values ​​of the d-axis extended current, speed, and q-axis stator current of the previous control cycle, the first difference between the two d-axis extended current estimates and the second difference between the two q-axis stator current estimates, the estimated value of the d-axis extended current of the current control cycle is estimated, and the first difference between the two d-axis extended current estimates of the current control cycle is obtained. Based on the q-axis stator voltage of the current control cycle, and the estimated values ​​of the q-axis stator current, speed, and d-axis extended current of the previous control cycle, the first difference between the two d-axis extended current estimates and the second difference between the two q-axis stator current estimates, the estimated value of the q-axis stator current for the current control cycle is estimated, and the second difference between the two q-axis stator current estimates for the current control cycle is obtained.

9. The method of claim 8, wherein, The first state observer estimates the d-axis extended current estimate and the q-axis stator current estimate for the current control period by: wherein a d-axis extended current estimation value for the current control period, L is the estimated value of the q-axis stator current for the current control cycle. d Let L be the d-axis inductance. q Let u′ be the q-axis inductance. d0 u is the d-axis extended voltage of the current control cycle. q0 R is the q-axis stator voltage of the current control cycle. s Let be the stator resistance of the motor. an extended current estimate value of the d-axis for the last control period, q-axis stator current estimate for the previous control period, The estimated speed for the previous control cycle is ρ = L. q / L d g1 is the first gain coefficient, g2 is the second gain coefficient, and e id1 e is the first difference between the d-axis extended current of the previous control cycle and the estimated d-axis extended current. iq1 It is the second difference between the q-axis stator current of the previous control cycle and the estimated q-axis stator current.

10. The method of claim 5, wherein, The second adaptive observer includes a second state observer and an estimator. The step of inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis extended voltage of the current control cycle into the second adaptive observer to obtain the estimated speed and rotor position of the motor in the current control cycle includes: The d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis extended voltage of the current control cycle are input to the second state observer to obtain the first difference between the d-axis extended current and the estimated d-axis extended current, and the second difference between the q-axis stator current and the estimated q-axis stator current. The first difference between the d-axis extended current and the estimated d-axis extended current in the current control cycle, the second difference between the q-axis stator current and the estimated q-axis stator current, the d-axis extended current, and the q-axis stator current are input to the estimator to obtain the estimated speed and rotor position of the motor in the current control cycle.

11. The method of claim 10, wherein, The step of inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis extended voltage of the current control cycle to the second state observer to obtain a first difference between the d-axis extended current and the estimated d-axis extended current, and a second difference between the q-axis stator current and the estimated q-axis stator current, includes: Based on the d-axis extended voltage of the current control cycle, and the estimated values ​​of the d-axis extended current, speed, and q-axis stator current of the previous control cycle, the first difference between the two d-axis extended current estimates and the second difference between the two q-axis stator current estimates, the estimated value of the d-axis extended current of the current control cycle is estimated, and the first difference between the two d-axis extended current estimates of the current control cycle is obtained. Based on the q-axis extended voltage of the current control cycle, and the estimated values ​​of the q-axis stator current, speed, and d-axis extended current of the previous control cycle, the first difference between the two d-axis extended current estimates and the second difference between the two q-axis stator current estimates, the estimated value of the q-axis stator current for the current control cycle is estimated, and the second difference between the two q-axis stator current estimates for the current control cycle is obtained.

12. The method of claim 11, wherein, The second state observer estimates the d-axis extended current estimate and the q-axis stator current estimate for the current control period by: wherein an extended current estimation value for the d-axis for the current control period, L is the estimated value of the q-axis stator current for the current control cycle. d Let L be the d-axis inductance. q Let u′ be the q-axis inductance. d0 The d-axis extended voltage of the current control cycle, u′ q0 R is the q-axis extended voltage of the current control cycle. s Let be the stator resistance of the motor. an extended current estimate value of the d-axis for the last control period, q-axis stator current estimate for the previous control period, The estimated speed for the previous control cycle is ρ = L. q / L d g1 is the first gain coefficient, g2 is the second gain coefficient, and e id1 e is the first difference between the d-axis extended current of the previous control cycle and the estimated d-axis extended current. iq1 It is the second difference between the q-axis stator current of the previous control cycle and the estimated q-axis stator current.

13. The method of claim 7 or 10, wherein, The step of inputting the first difference between the d-axis extended current and the estimated d-axis extended current in the current control cycle, the second difference between the q-axis stator current and the estimated q-axis stator current, the d-axis extended current, and the q-axis stator current to the estimator to obtain the estimated speed and rotor position of the motor in the current control cycle includes: Integrate the difference between the product of the second difference between the d-axis extended current and the q-axis stator current and the estimated q-axis stator current in the current control cycle and the product of the first difference between the q-axis stator current and the d-axis extended current and the estimated d-axis extended current in the current control cycle, to obtain the speed estimate for the current control cycle. Integrate the speed estimate of the current control cycle to obtain the rotor position change of the current control cycle, and obtain the rotor position change of the current control cycle and the rotor position estimate of the motor in the previous control cycle to obtain the rotor position estimate of the current control cycle.

14. A computer-readable storage medium, characterized in that, It stores a program that, when executed by a processor, implements the method according to any one of claims 1-13.

15. A speed estimation system of a sensorless permanent magnet synchronous motor, characterized by, include: A memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the method according to any one of claims 1-13.

16. A speed estimation device of a sensorless permanent magnet synchronous motor, characterized by, The device includes: The acquisition module is used to acquire the d-axis stator current and d-axis stator voltage of the motor in the current control cycle; An extension module is used to reconstruct the d-axis stator current and d-axis stator voltage of the current control cycle based on the rotor flux linkage and the d-axis inductance of the motor in the current control cycle, so as to obtain the d-axis extended current and d-axis extended voltage of the current control cycle. An adaptive observer is used to estimate the speed and rotor position of the motor in the current control cycle based on the d-axis extended current and d-axis extended voltage; wherein the adaptive observer is determined based on the voltage equation of the motor, the voltage equation including the d-axis inductance and q-axis inductance of the motor.

17. An electrical appliance characterized by This includes the speed estimation system for a sensorless permanent magnet synchronous motor according to claim 15, or the speed estimation device for a sensorless permanent magnet synchronous motor according to claim 16.

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