A memory motor permanent magnet magnetization state online estimation method, device and equipment

Abstract

The application discloses a memory motor permanent magnet magnetization state online estimation method, device and equipment, and relates to the technical field of permanent magnet motor control. The application detects the third voltage harmonic generated by the three-phase winding of the memory motor, and the third voltage harmonic signal is collected by a controller through an isolation amplifier and a signal conditioning circuit. The amplitude and phase of the third voltage harmonic signal are obtained through a phase-locked loop technology, and the amplitude of the voltage component generated by the permanent magnet is obtained after analysis. The magnetization state of the permanent magnet can be accurately estimated by detecting the amplitude of the voltage component generated by the permanent magnet. The application effectively solves the problem of memory motor permanent magnet magnetization state estimation. Compared with the traditional method, the method adopted by the application is independent of the motor driving part, the measurement circuit is simple and easy to implement, is not affected by the nonlinearity of the inverter and the winding resistance, does not need to inject an additional signal, and has stronger robustness.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet motor control technology, specifically to a method, apparatus, and equipment for online estimation of the magnetization state of a permanent magnet in a memory motor. Background Technology

[0002] Variable Flux Memory Machines (VFMMs) offer advantages such as high efficiency and a wide speed range. Utilizing low-coercivity permanent magnet materials, they can be magnetized or demagnetized using brief current pulses, allowing for flexible adjustment of the permanent magnet's magnetization state. This reduces additional excitation losses in the weak magnetic field region while ensuring considerable torque output in the constant torque region. These characteristics enable VFMMs to maintain high efficiency across a wide speed range. However, to effectively control the permanent magnet's magnetization state in VFMMs and quickly identify unexpected demagnetization, more accurate and reliable methods for estimating the permanent magnet's magnetization state are needed.

[0003] Currently, there are two existing methods for estimating the magnetization state of permanent magnets in memory motors: one is to provide an improved permanent magnet flux linkage observer, which uses a structured neural network to describe the relationship between inductance, current, and the magnetization state of the permanent magnet; the other is to use an improved adaptive nonlinear filter to realize online observation of the permanent magnet flux linkage and achieve closed-loop control of the magnetization state of the permanent magnet. However, both methods require parameters such as stator resistance and inductance during use, which will change significantly during the actual operation of the memory motor, thus reducing the performance of the flux linkage observer. Therefore, we propose an online estimation method, device, and equipment for the magnetization state of permanent magnets in memory motors. Summary of the Invention

[0004] The purpose of this invention is to provide an online estimation method, apparatus, and device for the magnetization state of a permanent magnet in a memory motor. When estimating the magnetization state of the permanent magnet, it is not necessary to obtain specific parameter values ​​of resistance and quadrature-axis inductance, thereby improving the dynamic performance of flux linkage estimation.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an online estimation method for the magnetization state of a permanent magnet in a memory motor, comprising:

[0006] Receive and collect the third harmonic voltage of the memory motor winding. RN ;

[0007] By analyzing the third voltage harmonic v RN The Park transform is performed, and the third voltage harmonic v is obtained using a single-phase phase-locked loop method. RN amplitude V RN and phase difference δ;

[0008] Third voltage harmonic v RN The component on the dq axis is represented as V. 3rd-d and V 3rd-q After further calculation using dq orthogonal decoupling, the component V of the third voltage harmonic on the d-axis is obtained. 3rd-d ;

[0009] Receive the acquired d-axis current i d Based on the obtained third voltage harmonic d-axis component V 3rd-d A third harmonic permanent magnet flux linkage observer was constructed for real-time observation of the third harmonic permanent magnet flux linkage.

[0010] Furthermore, the third voltage harmonic v RN The component on the dq axis is represented as V. 3rd-d and V 3rd-q Specifically:

[0011]

[0012] In equation (1), ω is the electric angular velocity, and L 3rd-d and L 3rd-q These are the third harmonic d-axis inductance and q-axis inductance, respectively, ψ 3rd-PM Third harmonic permanent magnet flux linkage, i d and i q These are the d-axis and q-axis currents, respectively.

[0013] Furthermore, the third voltage harmonic v RN It can be expressed as

[0014] v RN =V RN sin(3ωt+δ) (2)

[0015] In equation (2), ω is the electric angular velocity, t is time, and δ is the phase difference.

[0016] Furthermore, the amplitude V of the third voltage harmonic RN And its phase difference δ with the d-axis can be expressed as:

[0017]

[0018] Furthermore, the unidirectional phase-locked loop algorithm uses a second-order generalized integrator as its orthogonal signal generator.

[0019] Furthermore, the constructed third harmonic permanent magnet flux linkage observer includes a third harmonic inductor L 3rd-d constant.

[0020] According to one aspect of the present invention, the present invention provides an online estimation device for the magnetization state of a permanent magnet in a memory motor, comprising:

[0021] The receiving module is used to receive the acquired third voltage harmonic of the memory motor winding. RN ;

[0022] The coordinate transformation module is used to transform the third voltage harmonic v RN Performing Park transformation, the third voltage harmonic v RN The component on the dq axis is represented as V. 3rd-d and V 3rd-q ;

[0023] The calculation module is used to obtain the third voltage harmonic v using a single-phase phase-locked loop algorithm. RN amplitude V RN And the phase difference δ, and further calculate the component V of the third voltage harmonic on the d-axis. 3rd-d ;

[0024] The flux linkage observation module receives the acquired d-axis current i d Based on the obtained third voltage harmonic d-axis component V 3rd-d A third harmonic permanent magnet flux linkage observer was constructed for real-time observation of the third harmonic permanent magnet flux linkage.

[0025] According to another aspect of the present invention, a terminal device is provided, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor. The memory stores the computer program capable of running on the processor, and when the processor loads and executes the computer program, it employs the aforementioned online estimation method for the magnetization state of a permanent magnet in a memory motor.

[0026] The present invention has at least the following beneficial effects:

[0027] The online estimation method for the magnetization state of permanent magnets in a memory motor proposed in this invention is not affected by inverter nonlinearity. When estimating the magnetization state of the permanent magnet, it is not necessary to obtain specific parameter values ​​of resistance and quadrature-axis inductance. This is of great significance for systems like memory motors where parameters change drastically within the operating range. The use of a single-phase phase-locked loop improves the dynamic performance of flux linkage estimation and enhances the magnetization effect of the memory motor. In addition, the online estimation method for the magnetization state of permanent magnets proposed in this invention has a simple structure and does not require additional signal injection to affect the control system.

[0028] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0029] Figure 1 This is a block diagram illustrating the principle of an online estimation method for the magnetization state of permanent magnets in a memory motor based on third harmonic voltage detection.

[0030] Figure 2 This is a block diagram of a single-phase phase-locked loop scheme based on two-phase quadrature signals.

[0031] Figure 3 This is a block diagram of the principle of a third harmonic permanent magnet flux linkage observer. Detailed Implementation

[0032] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0033] The present invention proposes an online estimation method for the magnetization state of permanent magnets in memory motors, which mainly consists of three parts: a third harmonic voltage isolation and acquisition circuit, a single-phase phase-locked loop based on two-phase quadrature signals, and a third harmonic permanent magnet flux linkage observer. The overall principle block diagram is shown below. Figure 1 As shown, the third voltage harmonic acquisition circuit is isolated from the controller analog-to-digital conversion module through an isolation amplifier; the single-phase phase-locked loop based on two-phase quadrature signals extracts the amplitude and phase of the acquired voltage signal and further calculates the voltage component amplitude containing the induced voltage of the third permanent magnet flux linkage; based on the obtained voltage component amplitude and direct-axis current, the constructed third flux linkage observer will follow the third permanent magnet flux linkage in real time, realizing online estimation of the magnetization state of the permanent magnet of the memory motor.

[0034] Please see Figure 1 This invention provides a technical solution: an online estimation method for the magnetization state of a permanent magnet in a memory motor based on third voltage harmonic detection, comprising:

[0035] Receive and collect the third harmonic voltage of the memory motor winding. RN ;

[0036] By analyzing the third voltage harmonic v RN Park transform is performed, and a single-phase-locked loop method based on extended Kalman filter (EKF) is used to construct a state-space model of signal and noise. The estimates of state variables are updated using the estimates of the previous time step and the observations of the current time step, and the estimates of the current time step are obtained.

[0037] A single-phase phase-locked loop (PLL) consists of a detector, a loop filter, and a voltage-controlled oscillator. The implementation steps involve the detector acquiring the third voltage harmonic signal v. RNThe voltage signal, along with the frequency value ω, is input to a delay-shifting module consisting of a filter and a control oscillator. The acquired voltage signal is subtracted from the delayed output signal of the delay-shifting module, and the result is divided by 2 to obtain a voltage signal without DC offset. This signal is then used as the input signal for the enhanced phase-locked loop (PLL) to obtain the third voltage harmonic v of the current cycle. RN The amplitude and phase angle values ​​are used to obtain the third voltage harmonic v. RN amplitude V RN and phase difference δ;

[0038] Third voltage harmonic v RN The component on the dq axis is represented as V. 3rd-d and V 3rd-q After further calculation using dq orthogonal decoupling, the component V of the third voltage harmonic on the d-axis is obtained. 3rd-d ;

[0039] Receive the acquired d-axis current i d Based on the obtained third voltage harmonic d-axis component V 3rd-d A third harmonic permanent magnet flux linkage observer was constructed for real-time observation of the third harmonic permanent magnet flux linkage.

[0040] The specific implementation steps are as follows:

[0041] S1. Acquire the third voltage harmonic v generated by the memory motor winding. RN .

[0042] S2. In a synchronously rotating coordinate system, the components of the third voltage harmonic on the quadrature and direct axes can be expressed as:

[0043]

[0044] Equation (1) is the mathematical expression for the third harmonic permanent magnet flux linkage observer, where ω is the electric angular velocity, and L is the electric angular velocity. 3rd-d and L 3rd-q These are the third harmonic d-axis inductance and q-axis inductance, respectively, ψ 3rd-PM Third harmonic permanent magnet flux linkage. According to equation (1), the collected third voltage harmonic v RN It can be expressed as

[0045] v RN =V RN sin(3ωt+δ) (2)

[0046] The amplitude V of the third voltage harmonic in equation (2) RN And its phase difference δ with the d-axis can be expressed as follows:

[0047]

[0048] S3. Extracting the third voltage harmonic using a single-phase phase-locked loop algorithm.RN amplitude V RN And phase δ, and further calculate the third voltage harmonic component V on the direct axis. 3rd-d A single-phase phase-locked loop (PLL) scheme based on two-phase quadrature signals is adopted, and its structure is as follows: Figure 2 As shown, a second-order generalized integrator is used as an orthogonal signal generator.

[0049] S4. Construct a third harmonic permanent magnet flux linkage observer according to equation (1), the structure of which is as follows: Figure 3 As shown, V obtained from S3 3rd-d and the collected i d By observing the third harmonic permanent magnet flux linkage, online estimation of the magnetization state of the permanent magnet can be achieved, specifically L... 3rd-d The value can be obtained through offline experiments.

[0050] It should be noted that the third harmonic permanent magnet flux linkage observer consists of two parts: the magnetic field sensor converts the internally generated induced electromotive force measurement into an electrical signal, which is then amplified by the signal processor and recorded by the data acquisition unit to determine the magnetic field strength and direction.

[0051] The analysis of this invention is also applicable to memory motors with other structures. The structure and parameters of single-phase phase-locked loops and third harmonic permanent magnet flux linkage observers need to be designed according to actual needs. The above description is only a preferred embodiment of this invention.

[0052] According to one aspect of the present invention, the present invention provides an online estimation device for the magnetization state of a permanent magnet in a memory motor, comprising:

[0053] The receiving module is used to receive the acquired third voltage harmonic of the memory motor winding. RN ;

[0054] The coordinate transformation module is used to transform the third voltage harmonic v RN Performing Park transformation, the third voltage harmonic v RN The component on the dq axis is represented as V. 3rd-d and V 3rd-q ;

[0055] The calculation module is used to obtain the third voltage harmonic v using a single-phase phase-locked loop algorithm. RN amplitude V RN And the phase difference δ, and further calculate the component V of the third voltage harmonic on the d-axis. 3rd-d ;

[0056] The flux linkage observation module receives the acquired d-axis current i d Based on the obtained third voltage harmonic d-axis component V 3rd-dA third harmonic permanent magnet flux linkage observer was constructed for real-time observation of the third harmonic permanent magnet flux linkage.

[0057] According to another aspect of the present invention, a terminal device is provided, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor. The memory stores the computer program capable of running on the processor, and when the processor loads and executes the computer program, it employs the aforementioned online estimation method for the magnetization state of a permanent magnet in a memory motor.

[0058] It should be noted that the terminal device can be a computer device such as a desktop computer, a laptop computer, or a cloud server, and the terminal device includes, but is not limited to, a processor and a memory. For example, the terminal device may also include input / output devices, network access devices, and buses.

[0059] Furthermore, the processor can be a central processing unit (CPU). Of course, depending on the actual use, other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), off-the-shelf programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. can also be used. The general-purpose processor can be a microprocessor or any conventional processor, etc., and this application does not limit it in this regard.

[0060] Furthermore, the memory can be an internal storage unit of the terminal device, such as a hard disk or RAM of the terminal device, or an external storage device of the terminal device, such as a plug-in hard disk, smart memory card (SMC), secure digital card (SD), or flash memory card (FC) equipped on the terminal device. In addition, the memory can also be a combination of internal storage units and external storage devices of the terminal device. The memory is used to store computer programs and other programs and data required by the terminal device. The memory can also be used to temporarily store data that has been output or will be output. This application does not limit this.

[0061] Furthermore, through this terminal device, any one of the online estimation methods for the magnetization state of the permanent magnet of the memory motor in the above embodiments can be stored in the memory of the terminal device, and loaded and executed on the processor of the terminal device for convenient use.

[0062] This application also discloses a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it employs any of the online estimation methods for the magnetization state of a permanent magnet in a memory motor as described in the above embodiments.

[0063] The computer program can be stored in a computer-readable medium. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or certain middleware. The computer-readable medium includes any entity or device capable of carrying computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the computer-readable medium includes, but is not limited to, the above-mentioned components.

[0064] It should be further noted that, through this computer-readable storage medium, any one of the online estimation methods for the magnetization state of the permanent magnet in the memory motor described in the above embodiments can be stored in the computer-readable storage medium and loaded and executed on the processor, so as to facilitate the storage and application of the above methods.

[0065] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0066] For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances. When an element is referred to as being "assembled on," "mounted on," "fixed to," or "set on" another element, it may be directly on the other element or there may be an intermediate element present. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible embodiments.

[0067] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0068] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. An online estimation method for the magnetization state of a permanent magnet in a memory motor, comprising: Receive and collect the third voltage harmonic of the memory motor winding v RN ; By analyzing the third voltage harmonic v RN Park transformation is performed, and the third voltage harmonic is obtained using a single-phase phase-locked loop method. v RN amplitude V RN and phase difference δ; Third voltage harmonic v RN exist dq The components on the axis are represented as and ,go through dq Further calculations using orthogonal subtraction and cross-section yielded the third voltage harmonic at... d Components on the axis V 3rd-d ; Third voltage harmonic v RN exist dq The components on the axis are represented as and Specifically: （1） In equation (1), ω Electric angular velocity, L 3rd-d and L 3rd-q Third harmonic d Shaft inductance and q Shaft inductor, ψ 3rd-PM Third harmonic permanent magnet linkage i d and i q They are respectively d , q shaft current; The third voltage harmonic v RN It can be expressed as （2） In equation (2), ω Let t be the electric angular velocity and t be the time. δ is Phase difference; Amplitude of the third voltage harmonic V RN and its relationship with d Phase difference between axes δ They can be represented as follows: （3） Received and collected d shaft current i d Based on the obtained third voltage harmonic d-axis components V 3rd-d A third harmonic permanent magnet flux linkage observer was constructed for real-time observation of the third harmonic permanent magnet flux linkage.

2. The method for online estimation of the magnetization state of a permanent magnet in a memory motor according to claim 1, characterized in that: The single-phase phase-locked loop algorithm uses a second-order generalized integrator as its orthogonal signal generator.

3. The method for online estimation of the magnetization state of a permanent magnet in a memory motor according to claim 1, characterized in that, The constructed third harmonic permanent magnet flux linkage observer includes a third harmonic inductor. L 3rd-d constant.

4. An online estimation device for the magnetization state of a permanent magnet in a memory motor, used to implement the online estimation method for the magnetization state of a permanent magnet in a memory motor according to any one of claims 1 to 3, characterized in that, include: The receiving module is used to receive the acquired third voltage harmonics of the memory motor windings. v RN ; The coordinate transformation module is used to transform the third voltage harmonic. v RN Performing Park transformation, third voltage harmonic v RN exist dq The components on the axis are represented as and ; The calculation module is used to obtain the third voltage harmonic using a single-phase phase-locked loop algorithm. v RN amplitude V RN and phase difference δ Furthermore, the third voltage harmonic was calculated. d Components on the axis V 3rd-d ; The magnetic flux linkage monitoring module receives the acquired data. d shaft current i d Based on the obtained third voltage harmonic d-axis components V 3rd-d A third harmonic permanent magnet flux linkage observer was constructed for real-time observation of the third harmonic permanent magnet flux linkage.

5. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that, The memory stores a computer program that can run on a processor. When the processor loads and executes the computer program, it employs an online estimation method for the magnetization state of a permanent magnet in a memory motor, as described in any one of claims 1 to 3.

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