Backstepping expansion state observer, method, device and system for multiple harmonic suppression

Abstract

The invention discloses a backstepping expansion state observer, method, device and system for multiple harmonic suppression. The control method comprises the following steps: acquiring alpha-beta-axis voltage and current signals of a motor, taking the alpha-beta-axis voltage and current signals of the motor as input of a back-stepping extended state observer for multiple harmonic suppression so as to obtain a back electromotive force vector of the motor, and inputting the back electromotive force vector of the motor into an orthogonal phase-locked loop to estimate a rotating speed and a position signal of the motor; and the rotating speed and the position signal of the motor are input into a motor closed-loop control system, so that position-sensorless closed-loop control of the permanent magnet synchronous motor is realized. According to the method, direct current bias of the back electromotive force and-5 times,-1 times, 3 times and 7 times of back electromotive force harmonic waves introduced due to current sampling errors, inverter dead-zone effects and inductance asymmetry can be effectively suppressed, so that rotor position estimation errors are reduced, and the precision of sensorless control is effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of permanent magnet synchronous motor control, and particularly relates to a backstepping expansion state observer, method, device, and system for multiple harmonic suppression. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) are widely used in industry due to their high power density and high efficiency. The rotor position of the motor plays a crucial role in the reliable and stable operation of the PMSM drive system. To reduce costs and size, extensive research has been conducted on sensorless control strategies for PMSMs. Based on their control principles, these strategies can be divided into two categories: high-frequency signal injection and fundamental frequency model methods. The high-frequency signal injection method requires injecting additional auxiliary signals into the motor stator, which inevitably increases system losses and noise. Therefore, it is generally suitable for the zero-speed and low-speed operating range of sensorless PMSM drive systems.

[0003] The fundamental frequency model method requires no additional auxiliary signal injection. It obtains speed and position information by designing an observer to estimate the back EMF or stator flux linkage, making it suitable for low, medium, and high-speed operating domains. Traditional back EMF observers are mainly divided into model reference adaptive, sliding mode observer, extended Kalman filter, full-order observer, and linear extended state observer. However, since the back EMF amplitude is proportional to the motor speed, when the motor is running at low speed, non-ideal factors such as current sampling error, inverter dead-time effect, harmonic components caused by inductor asymmetry, and DC bias can significantly reduce the signal-to-noise ratio of the back EMF component, thereby reducing the control accuracy of the fundamental frequency model method.

[0004] Linear extended state observers have been widely studied due to their ease of parameter design and stability analysis. The transfer function of a traditional linear extended state observer exhibits a second-order low-pass characteristic, causing the estimated back-EMF phase to lag behind the actual back-EMF phase. This leads to increased rotor position estimation errors, making steady-state position estimation errors unavoidable and positively correlated with the motor's operating frequency. While increasing the bandwidth can mitigate phase delay, it also reduces the ability to suppress interference. Furthermore, DC bias errors in the back-EMF and harmonic interference further degrade the accuracy of position estimation. An effective method to suppress such interference is to add an adaptive bandpass filter or notch filter after the back-EMF observer; however, these filters increase the observer order and computational cost.

[0005] In conclusion, achieving high-precision sensorless control of permanent magnet synchronous motors is of significant research importance. Summary of the Invention

[0006] The purpose of this invention is to provide a backstepping extended state observer, method, device, and system for multiple harmonic suppression, which solves the problem in existing sensorless control technology for permanent magnet synchronous motors where the traditional linear extended state observer exhibits second-order low-pass characteristics, making it difficult to accurately estimate the sinusoidal back electromotive force and suppress harmonics in the estimated back electromotive force, thereby increasing the rotor position estimation error.

[0007] This invention provides the following technical solution:

[0008] In a first aspect, the present invention provides a backstepping extended state observer with multiple harmonic suppression, the backstepping extended state observer comprising: The backstepping observer construction module is used to design the transfer function of a second-order adaptive complex coefficient filter with bandpass characteristics into a backstepping observer using the back-inference method, and outputs a back electromotive force vector containing fundamental and harmonic components. The harmonic separation module is used to introduce a complex coefficient structure on the basis of the backstepping observer and adopt a cross-decoupling method to achieve accurate separation of the fundamental component and specific harmonic components in the output back electromotive force vector. The back electromotive force output module is used to calculate and process the fundamental component output by the harmonic separation module to obtain a back electromotive force vector without harmonic components.

[0009] In one embodiment, the transfer function of the second-order adaptive complex coefficient filter with bandpass characteristics is: , In the formula, Let be the transfer function of a second-order adaptive complex coefficient filter with bandpass characteristics. These are the adjustable parameters of a second-order adaptive complex coefficient filter. For bandwidth, For the center frequency, For complex variables in the complex frequency domain, It is the imaginary unit.

[0010] In one implementation, the step of designing the transfer function of a second-order adaptive complex coefficient filter with bandpass characteristics as an inverse observation using the backstepping method includes: Based on the linear extended state observer, in order to enable the backstepping observer to possess the bandpass characteristics of the second-order adaptive complex coefficient filter, the parameters in the transfer function of the linear extended state observer are obtained by back-reasoning. and Configure the backstepping observer to have bandpass filtering capability and the characteristics of no phase delay and amplitude attenuation at the center frequency; The parameters and Configured as follows: , , In the formula, , For stator resistance, It is the q-axis inductance; Configured parameters and By substituting this into the transfer function of the linearly extended state observer, we obtain the transfer function of the backstepping observer.

[0011] In one implementation, the transfer function of the linearly extended state observer is: , In the formula, The transfer function for the linearly extended state observer. for Axis estimation of back electromotive force, for Actual back electromotive force of the shaft; Configured parameters and Substituting this into the transfer function of the linearly extended state observer, we obtain the transfer function of the backstepping observer as follows: , In the formula, Let the transfer function be the backstepping observer; The frequency domain expression of the backstepping observer is: , , In the formula, , , , They are respectively shaft current and voltage, and for Shaft estimation current, and for Error between estimated shaft current and actual current and These are estimated values ​​for unknown interference variables. and for Axis estimation of back electromotive force, .

[0012] In one embodiment, the complex coefficient structure is represented as: , In the formula, , , , These are the transfer functions corresponding to different harmonic components in the complex coefficient structure, used for suppressing and separating the -1st, -5th, 3rd, and 7th harmonics, respectively. For the adjustable parameters of the complex coefficient structure, For the center frequency, For complex variables in the complex frequency domain, It is the imaginary unit.

[0013] In one implementation, the backstepping extended state observer for multiple harmonic suppression is represented as: , , In the formula, , , , They are respectively shaft current and voltage, and for Shaft estimation current, and for Error between estimated shaft current and actual current , , For stator resistance, These are adjustable parameters for a second-order adaptive complex coefficient filter. For bandwidth, and for Axis estimation of the fundamental component in the back electromotive force. and for Axial estimation of the corresponding harmonic components in the back electromotive force. Let be the transfer function corresponding to different harmonic components in the complex coefficient structure. n =-5, -1, 3, 7 are harmonic orders. For complex variables in the complex frequency domain, The center frequency.

[0014] In one implementation, the transfer function of the backstepping extended state observer with multiple harmonic suppression... Represented as: , in, , In the formula, , , , , numerator coefficient , , , , , The coefficients in the denominator are the algebraic coefficients of the polynomial expansion.

[0015] Secondly, the present invention provides a permanent magnet synchronous motor control method based on a backstepping extended state observer with multiple harmonic suppression, the method comprising: Obtain permanent magnet synchronous motor Shaft voltage and current signals; motor The back electromotive force vector of the motor is obtained by using shaft voltage and current signals as inputs and a back-stepping extended state observer with multiple harmonic suppression. The motor speed and position signals are estimated using a phase-locked loop based on the motor's back electromotive force vector; The motor speed and position signals are input to the motor closed-loop control system to achieve sensorless closed-loop control of the permanent magnet synchronous motor.

[0016] Thirdly, the present invention provides a permanent magnet synchronous motor control device based on a backstepping extended state observer with multiple harmonic suppression, the device comprising: The acquisition module is used to acquire information about permanent magnet synchronous motors. Shaft voltage and current signals; A multi-harmonic suppression backstepped extended state observer is used to monitor the motor. The shaft voltage and current signals are used as inputs to obtain the estimated back electromotive force vector of the motor; The motor speed and position signal estimation module is used to estimate the motor speed and position signals based on the back electromotive force vector of the motor using a phase-locked loop; The motor speed and position signal transmission module is used to input the motor speed and position signals to the motor closed-loop control system to realize sensorless closed-loop control of the permanent magnet synchronous motor.

[0017] Fourthly, the present invention provides a permanent magnet synchronous motor control system, the system comprising the aforementioned permanent magnet synchronous motor control device.

[0018] Beneficial effects of this invention:

[0019] (1) The backstepping extended state observer of the present invention with multiple harmonic suppression is based on the design of a second-order adaptive complex coefficient filter (ACVF), which has bandpass properties and enhances the robustness to DC error and high-order harmonics without the need to add an additional filter.

[0020] (2) The backstep expansion state observer with multiple harmonic suppression of the present invention has the characteristic of frequency adaptation. At different operating frequencies of the motor, it can obtain the estimated back EMF without phase delay and amplitude attenuation, and eliminate the phase error in the estimated back EMF without phase compensation.

[0021] (3) The backstep expansion state observer of the present invention for multiple harmonic suppression introduces a complex coefficient structure for extracting harmonics, which can suppress the -5th, -1st, 3rd and 7th back EMF harmonics caused by current sampling error, inverter dead zone effect and inductor asymmetry.

[0022] (4) The permanent magnet synchronous motor control method of the present invention can avoid the phase lag and amplitude attenuation of the back EMF caused by the second-order low-pass characteristic of the traditional linear expansion state observer, and can effectively suppress the DC bias of the back EMF and the back EMF harmonics, thereby reducing the rotor position estimation error and effectively improving the accuracy of sensorless control. Attached Figure Description

[0023] The accompanying drawings, as part of this invention, are provided to further illustrate the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation thereof. Clearly, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0024] Figure 1 This is a schematic diagram of the backstepping extended state observer structure for multiple harmonic suppression provided in an embodiment of the present invention;

[0025] Figure 2 This is a flowchart of a permanent magnet synchronous motor control method according to an embodiment of the present invention;

[0026] Figure 3 Bode plots of a conventional linear extended state observer, a reduced-order quasi-resonant extended state observer, and a multi-harmonic suppressed anti-step extended state observer provided in one embodiment of the present invention; wherein, Figure 3 (a) shows the Bode plots of the traditional extended state observer and the reduced-order quasi-resonant extended state observer. Figure 3 (b) is the Bode plot of the backstepping extended state observer with multiple harmonic suppression;

[0027] Figure 4 For different Bode plot of the backstepping extended state observer under multiple harmonic suppression conditions;

[0028] Figure 5 For different Bode plot of the backstepping extended state observer under multiple harmonic suppression conditions;

[0029] Figure 6 For different Bode plot of the backstepping extended state observer under multiple harmonic suppression conditions;

[0030] Figure 7 For different Bode plot of the backstepping extended state observer under multiple harmonic suppression conditions;

[0031] Figure 8 This is a schematic diagram of a permanent magnet synchronous motor control system provided in an embodiment of the present invention;

[0032] Figure 9 These are steady-state experimental results for a traditional linear extended state observer;

[0033] Figure 10 The steady-state experimental results are for a reduced-order quasi-resonant extended state observer.

[0034] Figure 11 Steady-state experimental results for a backstepped extended state observer with multiple harmonic suppression;

[0035] Figure 12 This paper presents harmonic analysis of the back electromotive force (EMF) estimated along the α-axis in steady-state experimental results for a traditional linear extended state observer, a reduced-order quasi-resonant extended state observer, and a multi-harmonic-suppressed back-step extended state observer. Figure 12 (a) shows the harmonic analysis of the back electromotive force estimated along the α axis in the steady-state experimental results of the traditional linear extended state observer; Figure 12 (b) shows the harmonic analysis of the back electromotive force estimated along the α axis in the steady-state experimental results of the reduced-order quasi-resonant extended state observer; Figure 12 (c) shows the harmonic analysis of the back electromotive force estimated along the α axis in the steady-state experimental results of the back-stepping extended state observer with multiple harmonic suppression.

[0036] Figure 13 This presents experimental comparison results of position estimation error under acceleration conditions of a permanent magnet synchronous motor provided in one embodiment of the present invention; wherein, Figure 13 (a) shows the experimental results of position estimation error using a traditional linear extended state observer under acceleration conditions. Figure 13 (b) shows the experimental results of position estimation error using a reduced-order quasi-resonant extended state observer under acceleration conditions; Figure 13 (c) shows the experimental results of the position estimation error of the backstepping extended state observer using the multiple harmonic suppression of the present invention under acceleration conditions;

[0037] Figure 14This presents experimental comparison results of position estimation error under sudden load change conditions of a permanent magnet synchronous motor provided in one embodiment of the present invention; wherein, Figure 14 (a) shows the experimental results of the position estimation error using a traditional linear extended state observer under a sudden load change condition. Figure 14 (b) shows the experimental results of the position estimation error using a reduced-order quasi-resonant extended state observer under a sudden load change condition; Figure 14 (c) shows the experimental results of the position estimation error of the backstepped extended state observer using the multiple harmonic suppression of the present invention under the condition of sudden load change;

[0038] Figure 15 This presents experimental comparison results of position estimation error under a 2A DC disturbance injected along the α-axis, provided in one embodiment of the present invention; wherein, Figure 15 (a) shows the experimental results of position estimation error using a conventional linear extended state observer under a 2A DC disturbance injected along the α-axis. Figure 15 (b) shows the experimental results of position estimation error using a reduced-order quasi-resonant extended state observer under a 2A DC disturbance injected into the α-axis current; Figure 15 (c) shows the experimental results of the position estimation error of the backstepping extended state observer using the multiple harmonic suppression of the present invention under a 2A DC disturbance injected into the α-axis current.

[0039] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0040] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0041] like Figure 1 As shown in the figure, one embodiment of the present invention illustrates a multi-harmonic suppression backstepped extended state observer. This multi-harmonic suppression backstepped extended state observer is based on a second-order complex coefficient filter and introduces a complex coefficient structure that separates harmonics and fundamental frequency components. The multi-harmonic suppression backstepped extended state observer includes: The backstepping observer construction module is used to design the transfer function of a second-order adaptive complex coefficient filter with bandpass characteristics into a backstepping observer using the back-inference method, and outputs a back electromotive force vector containing fundamental and harmonic components. The harmonic separation module is used to introduce a complex coefficient structure on the basis of the backstepping observer and adopt a cross-decoupling method to achieve accurate separation of the fundamental component and specific harmonic components in the output back electromotive force vector. The back electromotive force output module is used to calculate and process the fundamental component output by the harmonic separation module to obtain a back electromotive force vector without harmonic components.

[0042] The multi-harmonic suppressed backstep extended state observer selects an appropriate transfer function based on the expected characteristics of the extended state observer.

[0043] Furthermore, the transfer function of a second-order adaptive complex coefficient filter (ACVF) with bandpass characteristics is: , In the formula, Let be the transfer function of a second-order adaptive complex coefficient filter with bandpass characteristics. These are the adjustable parameters of a second-order adaptive complex coefficient filter. For bandwidth, For the center frequency, For complex variables in the complex frequency domain, It is the imaginary unit.

[0044] In this embodiment of the invention, the transfer function of a second-order adaptive complex coefficient filter with bandpass characteristics is designed as an inverse observer using a backstepping method, including: Based on the linear extended state observer, in order to enable the backstepping observer to possess the bandpass characteristics of the second-order adaptive complex coefficient filter, the parameters in the transfer function of the linear extended state observer are obtained by back-reasoning. and Configure the backstepping observer to have bandpass filtering capability and the characteristics of no phase delay and amplitude attenuation at the center frequency; parameter and Configured as follows: , , In the formula, , For stator resistance, It is the q-axis inductance.

[0045] Configured parameters and By substituting this into the transfer function of the linearly extended state observer, we obtain the transfer function of the backstepping observer.

[0046] Furthermore, the transfer function of the linearly extended state observer is: , In the formula, The transfer function for the linearly extended state observer. for Axis estimation of back electromotive force, for Actual back electromotive force of the shaft;

[0047] Configured parameters and Substituting this into the transfer function of the linearly extended state observer, we obtain the transfer function of the backstepping observer as follows: , In the formula, Let the transfer function be the backstepping observer;

[0048] The frequency domain expression of the backstepping observer is: , , In the formula, , , , They are respectively shaft current and voltage, and for Shaft estimation current, and for Error between estimated shaft current and actual current and These are estimated values ​​for unknown interference variables. and for Axis estimation of back electromotive force, .

[0049] To accurately separate the fundamental and harmonic waves for estimating the back electromotive force, a complex coefficient structure was introduced and a cross-decoupling method was adopted.

[0050] Furthermore, the complex coefficient structure is as follows: , In the formula, , , , These are the transfer functions corresponding to different harmonic components in the complex coefficient structure, used for suppressing and separating the -1st, -5th, 3rd, and 7th harmonics, respectively. For the adjustable parameters of the complex coefficient structure, For complex variables in the complex frequency domain, For the center frequency, It is the imaginary unit.

[0051] The fundamental and harmonic frequencies of the back electromotive force are estimated by the following frequency domain model: , In the formula, For bandwidth, , , and for Axis estimation of the fundamental component in the back electromotive force. and In order to be in The harmonic components of the corresponding order in the back electromotive force are estimated by the axis, where n = -5, -1, 3, and 7 are the harmonic orders.

[0052] Furthermore, the backstepping extended state observer with multiple harmonic suppression is represented as: , , In the formula, , , , They are respectively shaft current and voltage, and for Shaft estimation current, and for Error between estimated shaft current and actual current , , For stator resistance, These are adjustable parameters for a second-order adaptive complex coefficient filter. For bandwidth, and for Axis estimation of the fundamental component in the back electromotive force. and for Axial estimation of the corresponding harmonic components in the back electromotive force. Let be the transfer function corresponding to different harmonic components in the complex coefficient structure. n =-5, -1, 3, 7 are harmonic orders. For complex variables in the complex frequency domain, The center frequency.

[0053] Furthermore, the transfer function of the backstepped extended state observer with multiple harmonic suppression. Represented as: , in, , In the formula, , , , , numerator coefficient , , , , , The coefficients in the denominator are the algebraic coefficients of the polynomial expansion.

[0054] Furthermore, the back electromotive force vector without harmonic components is: , In the formula, and for Axis estimation of back electromotive force, and for The shaft contains a component that estimates the back electromotive force based on the fundamental frequency. It is the q-axis inductance.

[0055] Reference Figure 2 This invention discloses a method for controlling a permanent magnet synchronous motor based on a backstepping extended state observer with multiple harmonic suppression. The method specifically includes the following steps: Step S100: Obtain the permanent magnet synchronous motor Shaft voltage and current signals; Step S200: Move the motor The back electromotive force vector of the motor is obtained by using shaft voltage and current signals as inputs and a back-stepping extended state observer with multiple harmonic suppression. Step S300: Use a phase-locked loop to estimate the motor speed and position signals based on the motor's back electromotive force vector; Step S400: Input the motor speed and position signals to the motor closed-loop control system to realize sensorless closed-loop control of the permanent magnet synchronous motor.

[0056] For a description of the backstepping extended state observer based on multiple harmonic suppression, please refer to the description in the same or similar sections above, and it will not be repeated here.

[0057] Traditional linear extended state observers exhibit second-order low-pass characteristics, making it difficult to accurately estimate the sinusoidal back EMF and suppress harmonics in the estimated back EMF, thus increasing rotor position estimation errors. In contrast, the multi-harmonic suppression back-stepping extended state observer exhibits band-pass characteristics, demonstrating strong robustness to DC errors and higher harmonics. It can obtain back EMF estimates without phase lag at different motor operating frequencies and also resolves the influence of back EMF harmonics caused by current sampling errors, inverter dead-time effects, and inductor asymmetry.

[0058] To verify the ability of the multi-harmonic suppression inverse-step extended state observer to suppress DC bias and specific harmonics, as well as frequency adaptation, Bode plots of a traditional linear extended state observer, a reduced-order quasi-resonant extended state observer, and a multi-harmonic suppression inverse-step extended state observer are shown below. Figure 3 As shown. The motor operates at a frequency of 250Hz, and the bandwidth of a traditional linear extended state observer is... Bandwidth of the reduced-order quasi-resonant extended state observer Observer gain The bandwidth of the extended state observer for multiple harmonic suppression Adjustable parameters of a second-order adaptive complex coefficient filter Adjustable parameters of complex coefficient structure .in, Figure 3 (a) shows the Bode plots of the transfer functions of the traditional extended state observer and the reduced-order quasi-resonant extended state observer. It can be seen that the traditional linear extended state observer has a second-order low-pass characteristic, cannot suppress DC bias, and will cause phase lag in the estimated back EMF. The reduced-order quasi-resonant extended state observer can obtain an estimated back EMF without phase lag at the motor operating frequency, but it still cannot eliminate the influence of DC bias and current sampling error, inverter dead-time effect, and specific-order back EMF harmonics caused by inductor asymmetry. Figure 3 (b) is the Bode plot of the transfer function of the backstep extended state observer with multiple harmonic suppression. It can be seen that the backstep extended state observer with multiple harmonic suppression can obtain the estimated back electromotive force without phase lag, and has the ability to suppress DC bias and specific harmonics.

[0059] The backstepping extended state observer for multiple harmonic suppression includes adjustable parameters of a second-order adaptive complex coefficient filter. ,bandwidth Adjustable parameters of complex coefficient structure With center frequency . Figure 4 For different Bode plot of the backstepped extended state observer under multiple harmonic suppression conditions. Figure 4 It can be seen that, It is beneficial to enhance the DC bias suppression effect, but excessively large bias can lead to problems. This will reduce system stability, therefore The choice should balance the system's stability and the observer's DC bias suppression capability. Figure 5 For different Bode plot of the backstepped extended state observer under multiple harmonic suppression conditions. Figure 5 It can be seen that reducing It can enhance the suppression of harmonics to some extent, but the dynamic response will deteriorate. Figure 6 For different Bode plot of the backstepped extended state observer under multiple harmonic suppression conditions. Figure 6 It can be seen that, It will enhance the suppression of harmonics of a specified order, but excessively large... This will reduce system stability, therefore The choice should weigh the stability of the system against the ability of the observer to suppress the specified harmonics. Figure 7 For different Bode plot of the backstepped extended state observer under multiple harmonic suppression conditions. Figure 7 It can be seen that in different The amplitude-frequency characteristics of unity gain and zero phase delay can be maintained at all points.

[0060] After obtaining the estimated back EMF vector of the motor, a phase-locked loop is used to extract the motor speed and position information.

[0061] In one alternative implementation, after obtaining the motor speed, the method further includes: smoothing the estimated speed using a low-pass filter to suppress high-frequency noise introduced by the derivative.

[0062] The following is an embodiment of the permanent magnet synchronous motor control device based on the backstepping extended state observer of the present invention, which can be used to execute the permanent magnet synchronous motor control method embodiment based on the backstepping extended state observer of the present invention. For details not disclosed in the embodiment of the permanent magnet synchronous motor control device based on the backstepping extended state observer of the present invention, please refer to the embodiment of the permanent magnet synchronous motor control method based on the backstepping extended state observer of the present invention.

[0063] refer to Figure 8 The image shows a permanent magnet synchronous motor (PMSM) control device based on a backstepping extended state observer with multiple harmonic suppression, provided as an exemplary embodiment of the present invention. This PMSM control device can be implemented as all or part of a terminal through software, hardware, or a combination of both. The PMSM control device includes: The acquisition module is used to acquire information about permanent magnet synchronous motors. Shaft voltage and current signals; A multi-harmonic suppression backstepped extended state observer is used to monitor the motor. The shaft voltage and current signals are used as inputs to obtain the estimated back electromotive force vector of the motor; The motor speed and position signal estimation module is used to estimate the motor speed and position signals based on the back electromotive force vector of the motor using a phase-locked loop; The motor speed and position signal transmission module is used to input the motor speed and position signals to the motor closed-loop control system to realize sensorless closed-loop control of the permanent magnet synchronous motor.

[0064] In one alternative implementation, the permanent magnet synchronous motor control device based on the backstepping extended state observer with multiple harmonic suppression further includes a filter module for smoothing the estimated rotational speed using a low-pass filter to suppress high-frequency noise introduced by the derivative.

[0065] It should be noted that the permanent magnet synchronous motor control device based on the backstepping extended state observer with multiple harmonic suppression provided in the above embodiments is only illustrated by the division of the above functional modules when executing the permanent magnet synchronous motor control method based on the backstepping extended state observer with multiple harmonic suppression. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the permanent magnet synchronous motor control device based on the backstepping extended state observer with multiple harmonic suppression provided in the above embodiments and the permanent magnet synchronous motor control method embodiment based on the backstepping extended state observer with multiple harmonic suppression belong to the same concept. The implementation process is detailed in the embodiment of the permanent magnet synchronous motor control method based on the backstepping extended state observer with multiple harmonic suppression, and will not be repeated here.

[0066] Continue to refer to Figure 8 As shown, in one embodiment, a permanent magnet synchronous motor control system is proposed, which includes the aforementioned permanent magnet synchronous motor control device.

[0067] The specific working process of this system is as follows: The estimated rotor electric angular velocity... and the given rotor electric angular velocity The speed difference is obtained by subtracting the values; this speed difference is then input into the speed PI controller to obtain the given current for the dq axis. The three-phase current of the permanent magnet synchronous motor is obtained through current sampling. The three-phase current is first obtained by Clark transformation. shaft current The dq-axis current feedback value is then obtained through Park transformation. Set the current to the dq axis. and current feedback value The difference is calculated to obtain the current difference value; this current difference value is then input to the current PI controller to obtain the dq-axis reference voltage. The dq-axis reference voltage is obtained through coordinate transformation. shaft voltage ;Will The shaft voltage is input to the SVPWM modulation module, which outputs the duty cycle signal. The duty cycle signal is input to the DC bus side voltage. The inverter enables control over its on / off state, while simultaneously acquiring data from the acquisition module. A backstepped extended state observer with multiple harmonic suppression of shaft current and voltage inputs is obtained. Axis estimation of back electromotive force and ;Will The estimated back electromotive force of the shaft is input to the phase-locked loop to obtain the estimated rotor position. and estimated rotor electric angular velocity The estimated rotor electric angular velocity After high-order harmonics are filtered out by a low-pass filter, the remaining signal is used as the speed feedback for the next operation to control the permanent magnet synchronous motor.

[0068] For a description of the control device based on the permanent magnet synchronous motor, please refer to the description of the same or similar parts above, and it will not be repeated here.

[0069] The simulation was validated using a model built in MATLAB / Simulink. The parameters of the permanent magnet synchronous motor used were: rated power 750W, rated frequency 250Hz, rated speed 3000rpm, number of pole pairs 5, d-axis inductance 4.7mH, q-axis inductance 6.7mH, stator resistance 0.93Ω, permanent magnet flux linkage 0.053Wb, rated current 4.2A, and rated load 1.6N·m. The sampling frequency and switching frequency were both 10kHz.

[0070] Figure 9 , Figure 10 , Figure 11 The results are steady-state experimental results of different observers under half-rated load conditions with a motor speed of 1000 rpm. Figure 9 The steady-state experimental results are for a traditional linear extended state observer. Figure 10 The steady-state experimental results of the reduced-order quasi-resonant extended state observer are derived from... Figure 9 and Figure 10 It is known that traditional linear extended state observers and reduced-order quasi-resonant extended state observers cannot suppress the severe distortion of back EMF estimation and large fluctuations in rotor position estimation error caused by non-ideal factors such as gain error in current sampling, inverter dead-time effect and inductance asymmetry. Figure 11 Steady-state experimental results of the backstepped extended state observer with multiple harmonic suppression, from Figure 11 It can be seen that the back EMF waveform estimated by the back-step expansion state observer with multiple harmonic suppression has almost no distortion and is close to the ideal back EMF trajectory, which can accurately track the motor rotor position signal. Figure 12 This paper presents harmonic analysis of the back electromotive force (EMF) estimated along the α-axis in steady-state experimental results for a traditional linear extended state observer, a reduced-order quasi-resonant extended state observer, and a multi-harmonic-suppressed back-step extended state observer. Figure 12 (a) and Figure 12As shown in (b), the α-axis back electromotive force estimated using the traditional linear extended state observer and the reduced-order quasi-resonant extended state observer exhibits high levels of the 3rd, -5th, and 7th harmonics. Figure 12 As shown in (c), the backstepping extended state observer with multiple harmonic suppression can effectively suppress the above harmonics.

[0071] Figure 13 This paper presents experimental comparisons of position estimation errors under acceleration conditions for a traditional linear extended state observer, a reduced-order quasi-resonant extended state observer, and a multi-harmonic suppressed backstepped extended state observer. The motor speed was accelerated from 1000 rpm to 2000 rpm. (Refer to...) Figure 13 (a) and Figure 13 In (b), the maximum position estimation errors of the traditional linear extended state observer and the reduced-order quasi-resonant extended state observer during the entire dynamic process can reach 23.7 degrees and 8.33 degrees, respectively. (Refer to...) Figure 13 In (c), the maximum position estimation error during the entire dynamic process can be further limited to 7.57 degrees after adopting the backstep extended state observer with multiple harmonic suppression. This shows that the backstep extended state observer with multiple harmonic suppression can effectively improve the dynamic response capability of sensorless control and suppress the position estimation error generated during the dynamic process.

[0072] Figure 14 This paper presents experimental comparisons of position estimation errors under a sudden load change condition using a traditional linear extended state observer, a reduced-order quasi-resonant extended state observer, and a multi-harmonic suppressed anti-step extended state observer. The load abruptly changes from no load to 1.6 N·m, and then back to no load after reaching steady state. (Refer to...) Figure 14 (a) and Figure 14 In (b), the maximum position estimation errors of the traditional linear extended state observer and the reduced-order quasi-resonant extended state observer during the entire dynamic process can reach 28.23 degrees and 4.77 degrees, respectively. (Refer to...) Figure 14 In (c), the maximum position estimation error during the entire dynamic process can be further limited to 4.6 degrees after adopting the backstep extended state observer with multiple harmonic suppression. This shows that the backstep extended state observer with multiple harmonic suppression can effectively improve the dynamic response capability of sensorless control and suppress the position estimation error generated during the dynamic process.

[0073] Figure 15 This paper presents experimental comparisons of position estimation errors under a 2A DC disturbance injected into the α-axis by a traditional linear extended state observer, a reduced-order quasi-resonant extended state observer, and a multi-harmonic suppressed backstepped extended state observer. (Refer to...) Figure 15 (a) and Figure 15In (b), the rotor position estimation error of both the traditional linear extended state observer and the reduced-order quasi-resonant extended state observer shows significant fluctuations after the injection of a DC disturbance. (Refer to...) Figure 15 In (c), after adopting the backstep expansion state observer with multiple harmonic suppression, the rotor position estimation error did not change significantly before and after DC error injection. This indicates that the backstep expansion state observer with multiple harmonic suppression can significantly suppress the DC bias in the estimated back EMF caused by the DC bias error of current sampling, thereby accurately tracking the rotor position signal.

[0074] The experimental results above show that the permanent magnet synchronous motor control method of the present invention can avoid the phase lag and amplitude attenuation problems of back EMF estimation caused by the second-order low-pass characteristic of the traditional linear extended state observer. It can also effectively suppress the DC bias of back EMF and the -5th, -1st, 3rd and 7th back EMF harmonics introduced by current sampling error, inverter dead zone effect and inductor asymmetry, thereby reducing rotor position estimation error and effectively improving the accuracy of sensorless control of permanent magnet synchronous motor.

[0075] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0076] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A multiple harmonic-rejection backstepping extended state observer, characterized by: The backstepping extended state observer comprises: A backstepping observer construction module, configured to design a transfer function of a second-order adaptive complex coefficient filter with a band-pass characteristic into a backstepping observer by using a backstepping method, and output a back electromotive force vector containing a fundamental component and a harmonic component; A harmonic separation module, configured to introduce a complex coefficient structure and use a cross decoupling method on the basis of the backstepping observer, so as to realize accurate separation of the fundamental component and a specific order harmonic component in the output back electromotive force vector; A back electromotive force output module, configured to calculate and process the fundamental component output by the harmonic separation module, so as to obtain a back electromotive force vector without a harmonic component.

2. The harmonic-rejecting backstepping extended state observer of claim 1, wherein: The transfer function of the second-order adaptive complex coefficient filter with a band-pass characteristic is: ， wherein is the transfer function of a second order adaptive complex coefficient filter with bandpass characteristics, is an adjustable parameter of the second order adaptive complex coefficient filter, is the bandwidth, is the center frequency, is a complex variable in the complex frequency domain, is the imaginary unit.

3. The harmonic-rejecting, backstepping, extended state observer of claim 2, wherein: The backstepping method for designing the transfer function of the second-order adaptive complex coefficient filter with a band-pass characteristic into a backstepping observer comprises: Based on the linear extended state observer, in order to make the backstepping observer have the band-pass characteristic of the second-order adaptive complex coefficient filter, the backstepping method is used to configure the parameters in the transfer function of the linear extended state observer and The backstepping observer is configured to have the band-pass filtering capability and the characteristics of no phase delay and amplitude attenuation at the center frequency. The parameters And Configured to: ， ， wherein , is the stator resistance, is the q-axis inductance; Configured parameters and By substituting this into the transfer function of the linearly extended state observer, we obtain the transfer function of the backstepping observer.

4. The harmonic-rejecting, backstepping, extended state observer of claim 3, wherein: The transfer function of the linear extended state observer is: ， wherein is the linear extended state observer transfer function, is shaft estimated back emf, is shaft actual back emf; The configured parameters and Substitute into the linear extended state observer transfer function, the transfer function of the backstepping observer is: ， In the formula, is the transfer function of the backstepping observer; The frequency domain expression of the backstepping observer is: ， ， wherein , , , are respectively shaft current and voltage, and are respectively shaft estimated current, and are respectively error between shaft estimated current and actual current, and are respectively estimates of unknown disturbance variables, and are respectively shaft estimated back emf, .

5. The harmonic-rejecting, backstepping, extended state observer of claim 4, wherein: The complex coefficient structure is: ， wherein, , , , are transfer functions corresponding to different harmonic components in a complex coefficient structure, respectively, for suppression and separation of -1st, -5th, 3rd, 7th harmonics, is an adjustable parameter of the complex coefficient structure, is a complex variable in the complex frequency domain, is a center frequency, is the imaginary unit.

6. The harmonic-rejecting, backstepping, extended state observer of claim 5, wherein: The backstepping extended state observer for multiple harmonic suppression is expressed as: ， ， wherein , , , are shaft currents and voltages, and are shaft estimated currents, and are errors between shaft estimated currents and actual currents, , , is the stator resistance, is the adjustable parameter of the second order adaptive complex coefficient filter, is the bandwidth, and are fundamental components in shaft estimated back electromotive forces, and are harmonic components of corresponding orders in shaft estimated back electromotive forces, is the transfer function corresponding to different harmonic components in complex coefficient structure, n =-5, -1, 3, 7 are harmonic orders.

7. The harmonic-rejecting, backstepping, extended state observer of claim 6, wherein: Transfer function of a multi-harmonic rejection backstepping extended state observer is represented as: ， wherein, ， wherein , , , , is a numerator coefficient , , , , , is a denominator coefficient, is an algebraic coefficient after polynomial expansion.

8. A control method of a permanent magnet synchronous motor based on the multiple harmonic rejection backstepping extended state observer according to any one of claims 1-7, characterized in that: The method comprises: Acquiring permanent magnet synchronous motor Shaft voltage, current signals; Motor The motor voltage, current signals as input, through the multiple harmonic suppression of backstepping extended state observer to obtain motor back electromotive force vector; Estimating a motor speed and position signal according to a back electromotive force vector of the motor by using a phase-locked loop; Inputting the motor speed and position signal into a motor closed-loop control system to realize closed-loop control of the permanent magnet synchronous motor without a position sensor.

9. A permanent magnet synchronous machine control device based on the multiple harmonic rejection backstepping extended state observer according to any one of claims 1-7, characterized in that: The device comprises: An acquisition module is configured to acquire a permanent magnet synchronous motor Shaft voltage, current signals; A multi-harmonic rejection backstepping extended state observer for motor control The motor estimated back-emf vector is obtained by taking the shaft voltage and current signals as inputs A motor speed and position signal estimation module, configured to estimate a motor speed and position signal according to a back electromotive force vector of the motor by using a phase-locked loop; A motor speed and position signal transmission module, configured to input the motor speed and position signal into a motor closed-loop control system to realize closed-loop control of the permanent magnet synchronous motor without a position sensor.

10. A permanent magnet synchronous motor control system, characterized by: The system comprises the permanent magnet synchronous motor control device of claim 9.

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