A control method and system for a permanent magnet synchronous motor without position sensor
By constructing an adaptive observer to identify and compensate for the inverter, the problem of nonlinear modeling of the inverter was solved, the low-speed operation performance of the permanent magnet synchronous motor was improved, and the current harmonics and torque pulsation were reduced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANDONG UNIV
- Filing Date
- 2023-02-28
- Publication Date
- 2026-08-04
AI Technical Summary
Existing sensorless control methods for permanent magnet synchronous motors suffer from poor performance at low speeds due to the difficulty in modeling the nonlinearity of the inverter, resulting in poor robustness of the flux linkage observer.
By constructing an adaptive observer to identify and compensate the inverter, and calculating the inverter's output voltage compensation term, the low-speed operation performance of the flux linkage model method is improved.
Without requiring precise knowledge of semiconductor device characteristics, it improves current harmonics, reduces torque ripple, and enhances low-speed operating performance.
Smart Images
Figure CN116248000B_ABST
Abstract
Description
Technical Field
[0001] This disclosure belongs to the field of permanent magnet synchronous motor control technology, specifically relating to a sensorless control method and system for a permanent magnet synchronous motor. Background Technology
[0002] The statements in this section are merely background information relating to this disclosure and do not necessarily constitute prior art.
[0003] Position observation is crucial for sensorless control of permanent magnet synchronous motors. Current position observation methods mainly fall into two categories:
[0004] One type is based on signal injection, which involves injecting a characteristic voltage signal into the permanent magnet synchronous motor. Due to the salient pole effect of the motor, a signal containing position information will be modulated in the stator current, thereby obtaining the position information.
[0005] Another type is the motor model-based method, which is further divided into two categories: the flux linkage-based method and the back EMF-based method. The back EMF-based method is more sensitive to noise and is almost unsuitable at low speeds. The flux linkage-based method is not sensitive to noise and performs well at low speeds, thus becoming the mainstream of research.
[0006] According to the inventors, flux-based methods still require mathematical models of permanent magnet synchronous motors and inverters. The difficulty in modeling the nonlinear characteristics of the inverter has become a key factor limiting the low-speed performance of flux-based sensorless control. Traditional voltage-current hybrid models oversimplify inverter modeling, neglecting the effects of nonlinear factors such as dead-zone effects, causing the flux observer to fail at low speeds. Even with compensation for the dead-zone effect through other methods, the robustness of flux observation at low speeds is poor due to the observer's reliance on the accuracy of the motor model parameters, resulting in unsatisfactory performance. Summary of the Invention
[0007] To address the aforementioned issues, this disclosure proposes a sensorless control method and system for permanent magnet synchronous motors. By constructing an adaptive observer to identify and compensate for the sensor, the operating performance of the flux linkage-based model method at low speeds is improved.
[0008] According to some embodiments, the first solution of this disclosure provides a sensorless control method for a permanent magnet synchronous motor, which adopts the following technical solution:
[0009] A sensorless control method for a permanent magnet synchronous motor includes:
[0010] Obtain the stator current and stator voltage of the permanent magnet synchronous motor, and calculate the first active flux linkage based on the voltage model and the second active flux linkage based on the current model, respectively.
[0011] Calculate the matching error and inverter output voltage compensation term using the obtained first and second active flux linkages.
[0012] The inverter's drive signal is adjusted based on the obtained output voltage compensation term to achieve drive control of the permanent magnet synchronous motor.
[0013] As a further technical limitation, the voltage model is related to the stator resistance, stator current, quadrature axis inductance, stator voltage, and voltage model correction terms to be tuned of the permanent magnet synchronous motor.
[0014] Furthermore, the obtained stator current and stator voltage of the permanent magnet synchronous motor are input into the voltage model, and the output value of the voltage model is the first active flux linkage; the first active flux linkage for Where, r s L is the stator resistance. q For quadrature axis inductance, i s U is the stator current vector. s The stator terminal voltage vector, v VM This is the correction vector for the voltage model to be tuned.
[0015] As a further technical limitation, the current model is related to the rotor permanent magnet flux linkage, DC inductance, and DC current of the permanent magnet synchronous motor.
[0016] Furthermore, the obtained stator current and stator voltage of the permanent magnet synchronous motor are input into the current model, and the output value of the current model is the second active flux linkage; the second active flux linkage is... in, This is the second active flux linkage observation. The second active flux linkage amplitude, ψ f For rotor permanent magnet flux linkage, L d For a direct-axis inductor, L q For quadrature axis inductance, i d Direct-axis current, The rotor electrical angle is given.
[0017] As a further technical limitation, the matching error is the difference between the first active magnetic flux linkage and the second active magnetic flux linkage, i.e. Where ε is the matching error; according to Calculate the estimated value of the rotor's electric angular velocity. Estimated value of error voltage amplitude caused by inverter nonlinearity Obtain the output voltage compensation term of the inverter in, It is the adaptive gain matrix.
[0018] Furthermore, the estimated value of the rotor's electrical angular velocity Estimated value of error voltage amplitude caused by inverter nonlinearity satisfy: in, γ is the rotor electrical angle. VD For the adaptive gain of the inverter nonlinearity, γ ω For the adaptive gain of rotor electric angular velocity, For the first active magnetic flux The α-axis component, For the first active magnetic flux β-axis component, ε α Let ε be the α-axis component of the matching error ε. β The β-axis component of the matching error ε For the second active magnetic flux The α-axis component, For the second active magnetic flux The β-axis component.
[0019] Furthermore, the inverter's output voltage compensation term for Where sign is the sign function, i a i b i c These are the stator currents for phases a, b, and c, respectively.
[0020] As a further technical limitation, the obtained inverter output voltage compensation term is accumulated with the inverter output voltage, and the SVPWM modulation signal is controlled based on the obtained superimposed voltage value to control the synchronous motor.
[0021] According to some embodiments, the second solution of this disclosure provides a sensorless control system for a permanent magnet synchronous motor, which adopts the following technical solution:
[0022] A sensorless control system for a permanent magnet synchronous motor includes:
[0023] The calculation module is configured to obtain the stator current and stator voltage of the permanent magnet synchronous motor, calculate the first active flux linkage based on the voltage model and the second active flux linkage based on the current model, respectively; and calculate the matching error and the output voltage compensation term of the inverter based on the obtained first and second active flux linkages.
[0024] The control module is configured to adjust the inverter's drive signal based on the obtained output voltage compensation term to achieve drive control of the permanent magnet synchronous motor.
[0025] According to some embodiments, a third aspect of this disclosure provides a computer-readable storage medium, employing the following technical solution:
[0026] A computer-readable storage medium having a program stored thereon that, when executed by a processor, implements the steps of the sensorless control method for a permanent magnet synchronous motor as described in the first aspect of this disclosure.
[0027] According to some embodiments, the fourth solution of this disclosure provides an electronic device that adopts the following technical solution:
[0028] An electronic device includes a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the sensorless control method for a permanent magnet synchronous motor as described in the first aspect of this disclosure.
[0029] Compared with the prior art, the beneficial effects of this disclosure are as follows:
[0030] This disclosure fully considers the nonlinearity of the inverter. Without needing to know the characteristics of the semiconductor devices, it constructs an adaptive observer to identify and compensate for them, thereby improving the operating performance of the flux linkage-based model method at low speeds. Compensating for the nonlinearity of the inverter effectively improves current harmonics and reduces torque ripple. Attached Figure Description
[0031] The accompanying drawings, which form part of this disclosure, are used to provide a further understanding of this disclosure. The illustrative embodiments of this disclosure and their descriptions are used to explain this disclosure and do not constitute an undue limitation of this disclosure.
[0032] Figure 1 This is a flowchart of the sensorless control method for a permanent magnet synchronous motor according to Embodiment 1 of this disclosure;
[0033] Figure 2 This is a schematic diagram of the adaptive observer structure considering inverter nonlinearity identification in Embodiment 1 of this disclosure;
[0034] Figure 3 This is a control block diagram of the sensorless vector control method in Embodiment 1 of this disclosure;
[0035] Figure 4 This is a structural block diagram of the sensorless control system for a permanent magnet synchronous motor in Embodiment 2 of this disclosure. Detailed Implementation
[0036] The present disclosure will be further described below with reference to the accompanying drawings and embodiments.
[0037] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this disclosure. Unless otherwise specified, 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 disclosure pertains.
[0038] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this disclosure. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0039] Where there is no conflict, the embodiments and features described herein can be combined with each other.
[0040] Example 1
[0041] Embodiment 1 of this disclosure introduces a sensorless control method for a permanent magnet synchronous motor.
[0042] like Figure 1 The present invention discloses a sensorless control method for a permanent magnet synchronous motor, comprising:
[0043] Obtain the stator current and stator voltage of the permanent magnet synchronous motor, and calculate the first active flux linkage based on the voltage model and the second active flux linkage based on the current model, respectively.
[0044] Calculate the matching error and inverter output voltage compensation term using the obtained first and second active flux linkages.
[0045] The inverter's drive signal is adjusted based on the obtained output voltage compensation term to achieve drive control of the permanent magnet synchronous motor.
[0046] This embodiment constructs as follows: Figure 2 The active flux adaptive observer for permanent magnet synchronous motors shown here includes inverter nonlinearity identification. It adaptively compensates for inverter nonlinearity, improves the low-speed operation performance of permanent magnet synchronous motors, and reduces stator current harmonics and torque pulsation.
[0047] In this embodiment, Figure 2 The voltage model in is in, For the first active magnetic flux linkage, r s L is the stator resistance. q For quadrature axis inductance, i s U is the stator current vector. s The stator terminal voltage vector, v VM This is the voltage model correction term to be tuned.
[0048] In this embodiment, Figure 2 The mathematical equation for the current model in the text is: in, This is the second active flux linkage observation. The second active flux linkage amplitude, ψ f For rotor permanent magnet flux linkage, L d For a direct-axis inductor, L q For quadrature axis inductance, i d Direct-axis current, The rotor electrical angle is given.
[0049] In this embodiment, the adaptive laws of the current model and voltage model satisfy: in, γ is the rotor electrical angle. VD For the adaptive gain of the inverter nonlinearity, γ ω For the adaptive gain of rotor electric angular velocity, For the first active magnetic flux The α-axis component, For the first active magnetic flux β-axis component, ε α Let ε be the α-axis component of the matching error ε. β The β-axis component of the matching error ε For the second active magnetic flux The α-axis component, For the second active magnetic flux The β-axis component.
[0050] In this embodiment, the matching error ε is the first active magnetic flux linkage. With the second active magnetic flux The difference between them; because the matching error ε satisfies the formula The estimated value of the rotor's electric angular velocity can then be obtained. Estimated value of error voltage amplitude caused by inverter nonlinearity according to Calculate the rotor electrical angle to obtain for Where sign is the sign function, i a i b i c These are the stator currents for phases a, b, and c, respectively. It is the adaptive gain matrix.
[0051] This embodiment is combined with, for example Figure 3 The control block diagram shown provides a detailed introduction to the sensorless vector control method for permanent magnet synchronous motors.
[0052] Calculate the inverter output voltage In the process, the PI control and coordinate transformation between the dq axis and the αβ axis are all existing technologies, and related technologies such as those in patent CN 114465543 A or CN 109495048 A can be used; however, they will not be described in detail in this embodiment.
[0053] The obtained inverter output voltage compensation term With inverter output voltage The voltage values are summed and then SVPWM is applied to generate an SVPWM wave to drive the inverter, which in turn outputs AC power of the corresponding frequency, thereby achieving the drive control of the permanent magnet synchronous motor.
[0054] The sensorless control method for permanent magnet synchronous motors described in this embodiment takes into account the nonlinearity of the inverter during modeling. Without needing to know the characteristics of the semiconductor devices, an adaptive observer is constructed to identify and compensate for them, thereby improving the performance of the flux linkage-based model method at low speeds. On the other hand, since the nonlinearity of the inverter is compensated, current harmonics are effectively improved and torque pulsation is reduced.
[0055] Example 2
[0056] Embodiment 2 of this disclosure introduces a sensorless control system for a permanent magnet synchronous motor.
[0057] like Figure 4 The control system for a permanent magnet synchronous motor without position sensors, as shown, includes:
[0058] The calculation module is configured to obtain the stator current and stator voltage of the permanent magnet synchronous motor, calculate the first active flux linkage based on the voltage model and the second active flux linkage based on the current model, respectively; and calculate the matching error and the output voltage compensation term of the inverter based on the obtained first and second active flux linkages.
[0059] The control module is configured to adjust the inverter's drive signal based on the obtained output voltage compensation term to achieve drive control of the permanent magnet synchronous motor.
[0060] The detailed steps are the same as the sensorless control method for permanent magnet synchronous motors provided in Example 1, and will not be repeated here.
[0061] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.
[0062] While the specific embodiments of this disclosure have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of this disclosure. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of this disclosure are still within the scope of protection of this disclosure.
Claims
1. A sensorless control method for a permanent magnet synchronous motor, characterized in that, include: Obtain the stator current and stator voltage of the permanent magnet synchronous motor, and calculate the first active flux linkage based on the voltage model and the second active flux linkage based on the current model, respectively. Calculate the matching error and inverter output voltage compensation term using the obtained first and second active flux linkages. The inverter's drive signal is adjusted based on the obtained output voltage compensation term to achieve drive control of the permanent magnet synchronous motor; The voltage model is related to the stator resistance, stator current, quadrature axis inductance, stator voltage, and voltage model correction terms to be tuned for the permanent magnet synchronous motor. The obtained stator current and stator voltage of the permanent magnet synchronous motor are input into the voltage model, and the output value of the voltage model is the first active flux linkage; the first active flux linkage for ;in, For stator resistance, It is a quadrature axis inductor. The stator current vector, The stator terminal voltage vector, The correction vector for the voltage model to be tuned; The current model is related to the rotor permanent magnet flux linkage, DC inductance, and DC current of the permanent magnet synchronous motor; The obtained stator current and stator voltage of the permanent magnet synchronous motor are input into the current model, and the output value of the current model is the second active flux linkage; the second active flux linkage is... ;in, This is the second active flux linkage observation. The second active flux linkage amplitude, For rotor permanent magnet flux linkage, It is a direct-axis inductor. It is a quadrature axis inductor. Direct-axis current, The rotor electrical angle is given.
2. The sensorless control method for a permanent magnet synchronous motor as described in claim 1, characterized in that, The matching error is the difference between the first active magnetic flux linkage and the second active magnetic flux linkage, i.e. ;in, For matching error, As the first active magnetic flux linkage, For the second active magnetic flux linkage; according to Calculate the estimated value of the rotor's electric angular velocity. Estimated value of error voltage amplitude caused by inverter nonlinearity The output voltage compensation term of the inverter is obtained. ;in, This is the adaptive gain matrix. .
3. The sensorless control method for a permanent magnet synchronous motor as described in claim 2, characterized in that, The estimated value of the rotor's electric angular velocity Estimated value of error voltage amplitude caused by inverter nonlinearity satisfy: ;in, For rotor electrical angle, For the adaptive gain of the inverter nonlinearity, For the adaptive gain of the rotor's electric angular velocity, For the first active magnetic flux of Axial components, For the first active magnetic flux of Axial components, For matching error of Axial components, For matching error of Axial components, For the second active magnetic flux of Axial components, For the second active magnetic flux of Axial components.
4. The sensorless control method for a permanent magnet synchronous motor as described in claim 3, characterized in that, The inverter's output voltage compensation term for ;in, For symbolic functions, , , They are respectively a , b , c Phase stator current.
5. The sensorless control method for a permanent magnet synchronous motor as described in claim 1, characterized in that, The obtained output voltage compensation term of the inverter is accumulated with the output voltage of the inverter, and the SVPWM modulation signal is controlled according to the obtained superimposed voltage value to control the synchronous motor.
6. A sensorless control system for a permanent magnet synchronous motor, comprising a sensorless control method for a permanent magnet synchronous motor as described in any one of claims 1-5, characterized in that... include: The calculation module is configured to obtain the stator current and stator voltage of the permanent magnet synchronous motor, and calculate the first active flux linkage based on the voltage model and the second active flux linkage based on the current model, respectively. Calculate the matching error and inverter output voltage compensation term using the obtained first and second active flux linkages. The control module is configured to adjust the inverter's drive signal based on the obtained output voltage compensation term to achieve drive control of the permanent magnet synchronous motor.