Five-phase permanent magnet synchronous motor harmonic current control method and device based on impedance reshaping

Abstract

The application discloses a five-phase permanent magnet synchronous motor harmonic current control method and device based on impedance remodeling, relates to the high-performance driving control technical field of a multi-phase permanent magnet synchronous motor, and comprises the following steps: obtaining motor current, combining system total delay to calculate stability boundary, then selecting optimal virtual impedance, auxiliary attenuation gain parameter combination and current loop control bandwidth by using a Bode diagram, and constructing a current decoupling controller comprising an impedance remodeling channel, a coupling damping compensation channel and a proportional integral regulator; then inputting motor real-time operation information and a given reference current, so that a target reference voltage is obtained to drive the motor to operate. By means of optimal parameter combination, the motor port impedance is equivalently reconstructed, disturbances caused by the nonlinear dead zone of an inverter and the voltage drop of a switching tube are weakened, wide-frequency-domain harmonic current suppression is realized, the impedance remodeling channel, the coupling damping compensation channel and the proportional integral regulator jointly constitute a two-degree-of-freedom control structure, and the dynamic response speed and the anti-disturbance capability are decoupled and independently adjusted.

Description

Technical Field

[0001] This invention relates to the field of high-performance drive control technology for multiphase permanent magnet synchronous motors, and in particular to a harmonic current control method and device for a five-phase permanent magnet synchronous motor based on impedance reshaping. Background Technology

[0002] Five-phase permanent magnet synchronous motors (PMSMs) have shown broad application prospects in high-reliability drive fields such as electric vehicles, marine propulsion, and aerospace due to their high power density, low torque ripple, and excellent fault tolerance. Based on vector space decoupling theory, the variables of a five-phase PMSM can be mapped to the fundamental subspace and harmonic subspace. However, the equivalent impedance of the harmonic subspace of a five-phase PMSM is much smaller than that of the fundamental subspace, meaning that even small harmonic voltage disturbances can easily induce large-scale harmonic currents in the harmonic subspace. In practical engineering applications, due to factors such as inverter dead time, switching transistor voltage drop, and switching delay, the motor system inevitably generates multiple low-order harmonic currents, severely affecting the stable operation of the motor.

[0003] To suppress generated harmonic currents, traditional solutions typically employ proportional-integral (PI) control in a synchronous rotating coordinate system. However, PI controllers are inherently limited to zero steady-state error tracking of DC signals and, constrained by finite control bandwidth, are significantly inadequate in suppressing higher-frequency AC harmonic disturbances. Especially when dealing with multi-frequency harmonics, multiple proportional-resonant controller units often need to be paralleled to enhance the gain at specific frequencies, significantly increasing the complexity of the control algorithm. Furthermore, the cumbersome issue of multi-parameter coordinated tuning must be addressed, making the system highly susceptible to stability degradation due to parameter mismatch.

[0004] Active damping technology based on virtual impedance introduces virtual resistance into the control loop to effectively increase system damping and attenuate harmonics. However, since its control structure is essentially a single-degree-of-freedom framework, the reference tracking performance and disturbance suppression performance of the motor system are strongly coupled. If the virtual resistance is increased in order to improve the harmonic suppression effect, it will directly lead to a decrease in the closed-loop cutoff frequency of the system, thus significantly sacrificing the dynamic response speed of the current loop to a given signal. Moreover, the suppression gain is often concentrated in a specific narrow frequency band, making it difficult to achieve deep attenuation of complex harmonic disturbances over a wide frequency range. Summary of the Invention

[0005] This invention provides a harmonic current control method and device for a five-phase permanent magnet synchronous motor based on impedance reshaping, in order to solve the technical problem of how to achieve independent adjustment of reference tracking and harmonic suppression targets while ensuring the system's deep suppression of harmonics in a wide frequency range.

[0006] In a first aspect, embodiments of the present invention provide a harmonic current control method for a five-phase permanent magnet synchronous motor based on impedance reshaping, comprising:

[0007] S101 collects the five-phase current of the five-phase permanent magnet synchronous motor and obtains the delay information of the motor control system, decomposing the five-phase current into... d 1- q 1. Fundamental subspace components and d 3- q The three harmonic subspace components are calculated, and the stability boundary information of the two subspaces is calculated based on the total delay information.

[0008] S102 generates multiple sets of virtual impedance and auxiliary attenuation gain parameter combinations for two subspaces based on stability boundary information. At the same time, it generates multiple current loop control bandwidths based on the motor nameplate parameters and actual input current. Then, based on Bode plot frequency domain analysis, it selects a set of optimal parameter combinations and optimal current loop control bandwidths, and then calculates proportional-integral coefficients to construct the impedance reshaping channel, coupling damping compensation channel, and proportional-integral regulator of the current decoupling controller.

[0009] S103, real-time acquisition of five-phase stator current and rotor position information during motor operation and transformation to obtain d 1- q 1. Measured components of the fundamental subspace and d 3- q The measured components of the 3rd harmonic subspace, combined with the preset given reference current input current decoupling controller, obtain the reference regulating voltage through the proportional-integral regulator, obtain the impedance reshaping voltage through the impedance reshaping channel, and obtain the reference compensation voltage through the coupling damping compensation channel.

[0010] S104 calculates the target reference voltage for each coordinate axis in the two subspaces based on the impedance reshaping voltage, reference compensation voltage, and reference adjustment voltage, and converts the target reference voltage into drive signals for the inverter switching devices to drive the five-phase permanent magnet synchronous motor.

[0011] Secondly, embodiments of the present invention provide a harmonic current control device for a five-phase permanent magnet synchronous motor based on impedance reshaping, comprising:

[0012] The stability boundary calculation module is used to decompose the five-phase currents of the five-phase permanent magnet synchronous motor into... d 1- q 1. Fundamental subspace components and d 3- q The three harmonic subspace components are calculated, and the stability boundary information of the two subspaces is calculated based on the total delay information of the motor control system.

[0013] The frequency domain analysis optimization module is used to select an optimal combination of parameters and optimal current loop control bandwidth based on Bode plot frequency domain analysis from multiple sets of virtual impedance and auxiliary attenuation gain parameter combinations generated based on stability boundary information, and from multiple current loop control bandwidths generated based on motor nameplate parameters and actual input current, and to calculate proportional-integral coefficients to construct a current decoupling controller.

[0014] The current decoupling control module is used to collect the five-phase stator current and rotor position information of the motor in real time and transform them into two subspace measured components. Combined with the preset given reference current input current decoupling controller, the reference adjustment voltage, impedance reshaping voltage and reference compensation voltage are obtained.

[0015] The pulse width modulation drive module is used to calculate the target reference voltage of each coordinate axis in the two subspaces based on the impedance reshaping voltage, reference compensation voltage, and reference adjustment voltage, and convert it into drive signals for the inverter switching devices to drive the motor.

[0016] The current decoupling control module is a current decoupling controller, which includes a proportional-integral regulator, a coupling damping compensation channel, and an impedance reshaping channel.

[0017] Thirdly, embodiments of the present invention provide an electronic device, comprising:

[0018] One or more processors;

[0019] Storage device for storing one or more programs.

[0020] When the one or more programs are executed by the one or more processors, the one or more processors implement the above-described harmonic current control method for a five-phase permanent magnet synchronous motor based on impedance reshaping.

[0021] Fourthly, embodiments of the present invention provide a storage medium containing computer-executable instructions, which, when executed by a computer processor, are used to perform the above-described harmonic current control method for a five-phase permanent magnet synchronous motor based on impedance reshaping.

[0022] This invention provides a method and apparatus for harmonic current control of a five-phase permanent magnet synchronous motor based on impedance reshaping. The method comprehensively considers the total delay characteristics of the motor control system, including the delay of a control cycle generated by processor calculation, the equivalent delay caused by PWM holding, and the delay generated by the current conditioning circuit and sampling process. Based on this, the system stability boundary is calculated, and within the system stability boundary range, a set of optimal parameter combinations including virtual impedance formed by virtual resistance and virtual inductance and auxiliary attenuation gain is determined using Bode plot frequency domain analysis. The optimal current loop control bandwidth is also selected using Bode plot frequency domain analysis to calculate the proportional-integral coefficient. The impedance reshaping channel and coupling damping compensation channel of the current decoupling controller and the proportional-integral regulator are reshaped respectively. Then, the motor operating status is collected in real time and combined with the preset given reference current input to the reshaped current decoupling controller to output the final target reference voltage, which is used to form the motor drive signal. The impedance reshaping channel, reshaped by optimal parameter combination, effectively reconstructs the port impedance characteristics of the motor, effectively weakening the low-frequency and high-frequency composite disturbances caused by the inverter's nonlinear dead zone and tube voltage drop, achieving deep suppression of multiple harmonic currents in a wide frequency domain, and reducing the current harmonic distortion rate. The two-degree-of-freedom control structure, composed of the coupled damping compensation channel, the impedance reshaping channel, and the proportional-integral regulator, eliminates the adverse effects of active damping technology on the current loop PI command tracking performance, achieving decoupled independent adjustment of dynamic response speed and disturbance rejection capability. By introducing the system's inherent delay characteristics into the characteristic equation, the accuracy of stability boundary analysis can be improved, avoiding high-frequency instability caused by virtual damping, and enhancing the robustness and reliability of the control algorithm. Attached Figure Description

[0023] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0024] Figure 1 The flowchart is a method for controlling harmonic current of a five-phase permanent magnet synchronous motor based on impedance reshaping, as described in Embodiment 1 of the present invention.

[0025] Figure 2 This is a schematic diagram of the windings of the five-phase permanent magnet synchronous motor described in Embodiment 1 of the present invention;

[0026] Figure 3 This is a flowchart of a harmonic current control method for a five-phase permanent magnet synchronous motor based on impedance reshaping, as described in Embodiment 2 of the present invention.

[0027] Figure 4 This is a flowchart of a harmonic current control method for a five-phase permanent magnet synchronous motor based on impedance reshaping, as described in Embodiment 3 of the present invention.

[0028] Figure 5 This is a block diagram of the current decoupling controller structure based on impedance reshaping as described in Embodiment 3 of the present invention;

[0029] Figure 6 This is a schematic diagram of the five-phase permanent magnet synchronous motor drive system described in Embodiment 3 of the present invention;

[0030] Figure 7 The figure shows the experimental results of the D-phase current waveform of the five-phase permanent magnet synchronous motor described in Embodiment 4 of the present invention at 200 r / min.

[0031] Figure 8 This is a schematic diagram of the dynamic response and current harmonic suppression performance of the five-phase permanent magnet synchronous motor described in Embodiment 4 of the present invention when the speed changes from 400 r / min to 700 r / min in a step change.

[0032] Figure 9 The following are experimental results of the D-phase current waveform of the five-phase permanent magnet synchronous motor described in Embodiment 4 of the present invention under different methods under the same operating condition; wherein (a) is the experimental waveform of the traditional proportional integral control under the operating condition, (b) is the experimental waveform of the traditional proportional resonant control under the operating condition, (c) is the experimental waveform of the traditional active damping control under the operating condition, and (d) is the experimental waveform of the method of the present invention under the operating condition.

[0033] Figure 10 This is a schematic diagram of the structure of a harmonic current control device for a five-phase permanent magnet synchronous motor based on impedance reshaping, as described in Embodiment 5 of the present invention.

[0034] Figure 11 This is a structural diagram of the electronic device described in Embodiment Six of the present invention. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0036] Example 1

[0037] Figure 1 The flowchart below shows a harmonic current control method for a five-phase permanent magnet synchronous motor based on impedance reshaping, as described in Embodiment 1 of the present invention. By constructing a two-degree-of-freedom control architecture and reshaping the port impedance characteristics, the method aims to improve the motor's dynamic tracking performance and wide-frequency harmonic suppression capability under complex operating conditions. Specifically, it includes the following steps:

[0038] S101 collects the five-phase current of the five-phase permanent magnet synchronous motor and obtains the total delay information of the motor control system, decomposing the five-phase current into...d 1- q 1. Fundamental subspace components and d 3- q The three harmonic subspace components are calculated, and the stability boundary information of the two subspaces is calculated based on the total delay information.

[0039] In practical motor drive systems, inverter dead time, switching transistor voltage drop, and switching delay generate multiple error voltages, which in turn induce harmonic currents in the motor stator. The stator winding structure of a five-phase permanent magnet synchronous motor is as follows: Figure 2 As shown, its five-phase currents can be mapped to mutually orthogonal vectors based on the vector space decoupling transformation theory. d 1- q 1. Fundamental Subspace and d 3- q 3. Harmonic Subspace. Since the equivalent impedance of the harmonic subspace is much smaller than that of the fundamental subspace, even small harmonic voltage disturbances can easily induce large-amplitude harmonic currents. After vector space decoupling transformation, each subspace can be controlled independently. However, considering the inherent sampling delay and PWM update delay of the motor control system on the stability of the current loop, these delays can cause significant phase lag in the current control loop at high frequencies, leading to high-frequency whistling and abnormal heating of the motor, and potentially causing harmonic suppression strategies to fail. Therefore, it is necessary to calculate the stability boundary information of the two subspaces based on the total delay information of the motor control system to ensure impedance reshaping design within the range of maintaining stable motor operation to control harmonic currents, thus defining a safe range for subsequent parameter tuning.

[0040] S102 generates multiple sets of virtual impedance and auxiliary attenuation gain parameter combinations for two subspaces based on stability boundary information. At the same time, it generates multiple current loop control bandwidths based on the motor nameplate parameters and actual input current. Then, based on Bode plot frequency domain analysis, it selects an optimal parameter combination and an optimal current loop control bandwidth, and then calculates the proportional-integral coefficients to construct the impedance reshaping channel, coupling damping compensation channel, and proportional-integral regulator of the current decoupling controller.

[0041] Under the premise of satisfying the stability boundary, multiple sets of parameter combinations including virtual impedance and auxiliary attenuation gain are generated within the defined safety range. Specifically, these include three parameters: virtual resistance, virtual inductance, and auxiliary attenuation gain. Multiple sets of parameter combinations containing these three parameters are generated. By introducing virtual impedance, the impedance characteristics of the motor port can be reshaped, effectively increasing the system damping and thus suppressing harmonic currents. The auxiliary attenuation gain can be used to further optimize the attenuation performance in specific frequency bands. Simultaneously, candidate values ​​for the current loop control bandwidth can be determined based on the parameters recorded on the motor nameplate (such as stator resistance and inductance). Then, using Bode plot frequency domain analysis, the above multiple sets of parameter combinations and candidate values ​​for the current loop control bandwidth are optimized. The optimal parameter combination of virtual impedance and auxiliary attenuation gain is selected with the goal of minimizing the amplitude gain at the target harmonic frequency. Finally, the optimal current loop control bandwidth is selected by comprehensively considering the system's dynamic response speed and phase margin. Then, the proportional-integral coefficients are calculated based on the optimal current loop control bandwidth and configured into the proportional-integral regulator. At the same time, the impedance reshaping channel and the coupling damping compensation channel are configured according to the optimal parameter combination, forming a proportional-integral regulator for basic error adjustment, an impedance reshaping channel for enhancing disturbance rejection capability, and a coupling damping compensation channel for eliminating the coupling effect of impedance reshaping on reference tracking performance. These three components together constitute a current decoupling controller. Furthermore, through the impedance reshaping channel, the coupling damping compensation channel, and the proportional-integral regulator, a two-degree-of-freedom control structure is formed to achieve decoupled and independent adjustment of reference tracking performance and disturbance rejection performance.

[0042] S103, real-time acquisition of five-phase stator current and rotor position information during motor operation and transformation to obtain d 1- q 1. Measured components of the fundamental subspace and d 3- q The measured components of the 3rd harmonic subspace, combined with the preset given reference current input current decoupling controller, are used to obtain the reference regulating voltage through the proportional-integral regulator, the impedance reshaping voltage through the impedance reshaping channel, and the reference compensation voltage through the coupling damping compensation channel.

[0043] During real-time motor operation, five-phase stator current and rotor position information are collected in real time using current and position sensors. Similarly, the five-phase stator current is transformed through vector space decoupling. d 1- q 1. Measured components of the fundamental subspace and d 3- q 3. Measured components of the three harmonic subspaces. The measured components of the two subspaces and a preset reference current are input to the reshaped current decoupling controller described above. In the preset reference current, typically... d Set the reference current of axis 1 to 0. qThe reference current for axis 1 is determined by the output of the speed loop. d 3- q The reference current for the third harmonic subspace is set to 0. Inside the current decoupling controller, the proportional-integral regulator calculates the reference regulation voltage based on the current tracking error; the impedance reshaping channel calculates the impedance reshaping voltage based on the measured components of the two subspaces to enhance the system's disturbance rejection capability; and the damping compensation channel coupled to the impedance reshaping channel calculates the reference compensation voltage based on the reference regulation voltage to offset the negative impact of the impedance reshaping stage on command tracking. This two-degree-of-freedom control structure ensures that the system can effectively suppress harmonics while still quickly and accurately tracking the given current command.

[0044] S104 calculates the target reference voltage for each coordinate axis in the two subspaces based on the impedance reshaping voltage, reference compensation voltage, and reference adjustment voltage, and converts the target reference voltage into drive signals for the inverter switching devices to drive the five-phase permanent magnet synchronous motor.

[0045] The impedance reshaping voltage, reference compensation voltage, and reference adjustment voltage calculated above are combined and calculated. Specifically, the impedance reshaping voltage and the reference compensation voltage are summed, and then the difference is taken from the reference adjustment voltage to obtain the final output of the current decoupling controller, which corresponds to the two subspaces respectively. d 1. q 1. d 3. q The target reference voltage is defined by three coordinate axes. The voltage in the rotating coordinate system can then be converted to the stationary coordinate system using inverse Park transformation. Space vector pulse width modulation (SVPWM) technology is then used to calculate the duty cycle of each arm of the inverter based on the target voltage vector, generating PWM pulse signals to drive the five-phase permanent magnet synchronous motor.

[0046] This embodiment comprehensively considers the total delay characteristics of the motor control system, including the delay of one control cycle generated by processor calculation, the equivalent delay caused by PWM holding, and the delay generated by the current conditioning circuit and sampling process. Based on this, the system stability boundary is calculated, and within the system stability boundary range, a set of optimal parameter combinations including virtual impedance formed by virtual resistance and virtual inductance and auxiliary attenuation gain is determined using Bode plot frequency domain analysis. The optimal current loop control bandwidth is also selected using Bode plot frequency domain analysis to calculate the proportional-integral coefficient. The impedance reshaping channel and coupling damping compensation channel of the current decoupling controller and the proportional-integral regulator are reshaped respectively. Then, the motor operating status is collected in real time and combined with the preset given reference current input to the reshaped current decoupling controller to output the final target reference voltage, which is used to form the motor drive signal. The impedance reshaping channel, reshaped by optimal parameter combination, effectively reconstructs the port impedance characteristics of the motor, effectively weakening the low-frequency and high-frequency composite disturbances caused by the inverter's nonlinear dead zone and tube voltage drop, achieving deep suppression of multiple harmonic currents in a wide frequency domain, and reducing the current harmonic distortion rate. The two-degree-of-freedom control structure, composed of the coupled damping compensation channel, the impedance reshaping channel, and the proportional-integral regulator, eliminates the adverse effects of active damping technology on the current loop PI command tracking performance, achieving decoupled independent adjustment of dynamic response speed and disturbance rejection capability. By introducing the system's inherent delay characteristics into the characteristic equation, the accuracy of stability boundary analysis can be improved, avoiding high-frequency instability caused by virtual damping, and enhancing the robustness and reliability of the control algorithm.

[0047] Example 2

[0048] Figure 3 This is a flowchart of a harmonic current control method for a five-phase permanent magnet synchronous motor based on impedance reshaping, as described in Embodiment 2 of the present invention. This embodiment is an optimization based on the above embodiment. In this embodiment, S102 is specifically optimized as follows:

[0049] Based on the stability boundary information, multiple sets of parameter combinations including virtual resistance, virtual inductance and auxiliary attenuation gain are generated for each subspace. A motor system disturbance suppression transfer function including virtual resistance, virtual inductance and auxiliary attenuation gain is constructed. The amplitude-frequency characteristics of the transfer function are analyzed based on the Bode plot frequency domain. The optimization objective is to minimize the amplitude gain at the target harmonic frequency, and a set of optimal parameter combinations is selected.

[0050] The equivalent resistance and equivalent inductance of the motor are calculated based on the nameplate parameters of the motor. A closed-loop transfer function between the current loop reference current and the actual current is constructed in combination with the current decoupling controller to reflect the input of the motor. The current loop control bandwidth is configured as an adjustable parameter. The amplitude-frequency characteristics and phase-frequency characteristics of the closed-loop transfer function are analyzed based on the Bode plot frequency domain to obtain the phase margin and amplitude change of the motor system. The frequency with the largest closed-loop cutoff frequency and no significant resonance peak is selected as the optimal current loop control bandwidth according to the preset phase margin.

[0051] By configuring the impedance reshaping channel and the coupling damping compensation channel using the optimal parameter combination, and by calculating the proportional-integral coefficient using the optimal current loop control bandwidth and configuring the proportional-integral regulator, a current decoupling controller is formed, which includes the impedance reshaping channel, the coupling damping compensation channel, and the proportional-integral regulator.

[0052] Accordingly, the harmonic current control method for a five-phase permanent magnet synchronous motor based on impedance reshaping provided in this embodiment specifically includes:

[0053] S201 collects the five-phase current of the five-phase permanent magnet synchronous motor and obtains the total delay information of the motor control system, decomposing the five-phase current into... d 1- q 1. Fundamental subspace components and d 3- q The three harmonic subspace components are calculated, and the stability boundary information of the two subspaces is calculated based on the total delay information.

[0054] Specifically, the five-phase currents of the five-phase permanent magnet synchronous motor are collected and subjected to vector space decoupling transformation to obtain... d 1- q 1. Fundamental subspace components and d 3- q 3rd harmonic subspace component.

[0055] First, the original five-phase current is obtained through a current sensor. Then, based on the Clark transform and Park transform, the vector space decoupling transform projects the five-phase current into two independent subspaces, where... d 1- q 1. The fundamental subspace component mainly characterizes the fundamental magnetic field component in the air gap of the motor. It is the main channel for the motor to carry out electromechanical energy conversion. Its stability mainly affects the current tracking performance, torque output stability and the ability to suppress harmonic disturbances in the fundamental current channel. d 3- q The third harmonic subspace component mainly characterizes the harmonic magnetic field component in the air gap of the motor. It is an auxiliary channel for the motor to perform electromechanical energy conversion. Its stability is mainly used to constrain harmonic current oscillation and improve the overall operating stability of the system.

[0056] Based on the motor system sampling delay, PWM delay, and motor controller parameters in the total delay information, calculate the parameters that enable the motor to... d 1- q 1. Fundamental Subspace and d 3- q The control parameter range and bandwidth limitation range of a current-controlled closed-loop system operating stably in the 3rd harmonic subspace form the stability boundary information of the two subspaces.

[0057] The system stability boundary mainly refers to the stability boundary of the current control closed-loop system under conditions considering factors such as motor system sampling delay, PWM delay, and controller parameters. d 1- q 1. Fundamental Subspace and d 3- q The range and bandwidth limitations of control parameters that can maintain stable motor operation in the 3rd harmonic subspace. Among these, the system sampling delay (total system delay parameter) is... T d The total system delay is generated by current sampling and AD conversion, while the PWM delay is generated by updates during PWM modulation and computational delays from controller operations. These delay components introduce phase lag, reducing the system's phase margin and potentially leading to instability. Especially after introducing virtual impedance, if the virtual resistance or inductance is set too large, although it can enhance harmonic suppression, it will further deteriorate system stability. Therefore, the total system delay parameters are analyzed first. T d right d 1- q 1. Fundamental Subspace and d 3- q The influence of the dynamic characteristics of the 3rd harmonic subspace current controller is investigated, and the open-loop transfer function of the current loop is obtained. To simplify the analysis of the system characteristic equation containing the delay element, the first-order Pade approximation is used to treat the delay element equivalently, and the system characteristic equation containing the delay element is established to derive the parameter constraints required for the system to remain stable. The stability boundary of the impedance reshaping parameter corresponding to each coordinate axis can be expressed by the following formula:

[0058]

[0059] in, L v For virtual inductance; For the motor in d 1- q 1. Fundamental Subspace and d 3- q The equivalent inductance parameters corresponding to the 3rd harmonic subspace are derived from the motor nameplate or motor parameter identification results. R v For virtual resistance; Td The total system delay is derived from the delay characteristics analysis of the control system, including the delay of one control cycle generated by the processor operation, the equivalent delay caused by PWM holding, and the delay generated by the current regulation circuit and the sampling process, etc. K c The preset current loop control bandwidth is pre-set by the control system design requirements; This is the stator phase resistance of the motor, and its value is derived from the motor nameplate or parameter identification results. G aux For auxiliary attenuation gain; where R v Virtual resistance L v Virtual inductance G aux The three terms of auxiliary attenuation gain are output results, while the other terms are input data. Since the inductance of the harmonic subspace is usually much smaller than that of the fundamental subspace, its disturbance rejection capability is weaker and it is more sensitive to parameter changes. It is necessary to calculate different stability boundaries for the two subspaces separately, and tune the virtual inductance, virtual resistance, and auxiliary attenuation gain in each subspace to ensure that the parameters such as virtual resistance, virtual inductance, and auxiliary attenuation gain are always within the safe region, so as to improve the suppression capability of harmonic disturbances in each subspace while satisfying the system stability constraints.

[0060] S202. Based on the stability boundary information, generate multiple sets of parameter combinations for each subspace, including virtual resistance, virtual inductance, and auxiliary attenuation gain, and construct a motor system disturbance suppression transfer function including virtual resistance, virtual inductance, and auxiliary attenuation gain. Analyze the amplitude-frequency characteristics of this transfer function based on Bode plot frequency domain analysis, and select an optimal set of parameter combinations with the goal of minimizing the amplitude gain at the target harmonic frequency.

[0061] Under the premise of satisfying the above stability boundary, multiple sets of parameter combinations for virtual resistance, virtual inductance, and auxiliary attenuation gain are generated. For each set of parameters, a motor system disturbance suppression transfer function from disturbance input to current output is constructed. The motor system disturbance suppression transfer function is based on a current loop mathematical model that includes motor nameplate parameters, virtual impedance, and auxiliary attenuation gain. By introducing external disturbances and performing closed-loop modeling of the control system, the closed-loop transfer relationship between disturbance input and current output is derived through Laplace transform, which is used to characterize the system's ability to suppress disturbances. The formula is expressed as follows:

[0062]

[0063] in, L d,q For the motor in d 1- q 1. Fundamental Subspace and d 3-q The actual inductance parameters corresponding to the 3rd harmonic subspace. L v For virtual inductance, R s This represents the actual phase resistance of the motor stator. R v For virtual resistance, s For differential operators, G c The transfer function of the proportional-integral controller is expressed as follows: , Z aux It is an intermediate variable.

[0064]

[0065] in, This is the square of the mathematical model of a five-phase permanent magnet synchronous motor. G aux To assist in attenuating gain, The mathematical model of a five-phase permanent magnet synchronous motor is expressed by the formula as follows: Then, Bode plots were used to analyze the amplitude-frequency characteristics of the transfer function, focusing on the amplitude gain at the target harmonic frequencies of the 3rd, 7th, and 9th harmonics. Minimizing the amplitude gain at the target harmonic frequencies was used as the optimization objective. Through traversal search and other optimization algorithms, the set of parameters that maximizes the harmonic suppression depth was selected as the optimal parameter combination. R v , L v , G aux The optimal combination of parameters, rather than seeking the minimum or maximum of a single parameter, ensures that the impedance reshaping channel can perform at its maximum efficiency.

[0066] S203 calculates the equivalent resistance and equivalent inductance of the motor based on the motor's nameplate parameters, and constructs a closed-loop transfer function between the current loop reference current and the actual current, reflecting the motor input situation, in conjunction with the current decoupling controller. The current loop control bandwidth is configured as an adjustable parameter. Based on Bode plot frequency domain analysis, the amplitude-frequency characteristics and phase-frequency characteristics of the closed-loop transfer function are obtained to obtain the phase margin and amplitude change of the motor system. Based on the preset phase margin, the frequency with the largest closed-loop cutoff frequency and no significant resonance peak is selected as the optimal current loop control bandwidth.

[0067] Based on the motor nameplate parameters or parameter identification results, the equivalent resistance and equivalent inductance of the motor are obtained, and a closed-loop transfer function from the current loop reference current to the actual current is constructed. The current loop control bandwidth is used as an adjustable variable, and Bode plots are drawn for different bandwidths. The amplitude-frequency and phase-frequency characteristics of the Bode plots are analyzed to obtain the closed-loop cutoff frequency and phase margin of the system. The closed-loop cutoff frequency is determined by the amplitude-frequency curve and reflects the dynamic response speed of the system; a higher cutoff frequency indicates a faster response. The phase margin reflects the stability of the system; a larger margin indicates a more stable system. Under the premise of meeting the preset phase margin (e.g., 30 degrees or 45 degrees to prevent overshoot oscillation), the frequency that maximizes the closed-loop cutoff frequency and has no significant resonant peak is selected as the optimal current loop control bandwidth. k c The current loop is primarily used to limit its control speed and stability margin, and serves as an important basis for parameter tuning of the proportional-integral controller. By rationally selecting the current loop control bandwidth through frequency domain analysis, the system stability can be guaranteed while improving the current loop's ability to track reference commands and suppress harmonic disturbances. This allows the current loop to achieve high response speed and reference tracking capability while maintaining sufficient stability margin, thus realizing fast and stable control of the motor current.

[0068] S204 uses the optimal parameter combination to configure the impedance reshaping channel and the coupling damping compensation channel, calculates the proportional-integral coefficient using the optimal current loop control bandwidth and configures the proportional-integral regulator, forming a current decoupling controller that includes the impedance reshaping channel, the coupling damping compensation channel, and the proportional-integral regulator.

[0069] The optimal parameter combination is used as the input data for the impedance reshaping channel and the coupling damping compensation channel. Based on the determined optimal current loop control bandwidth, the proportional-integral coefficient is calculated using the bandwidth configuration formula, as follows:

[0070]

[0071]

[0072] in, k p It corresponds to the coordinate axis ( d 1 , q 1 , d 3 , q 3 The proportional coefficients of the proportional-integral adjustment module (one set for each of the four coordinate axes) are... k i These are the integral coefficients of the proportional-integral adjustment module under the corresponding coordinate axis. k c This is the preset current loop control bandwidth. For the motor in d 1- q 1. Fundamental Subspace and d 3- q The equivalent inductance parameters corresponding to the 3rd harmonic subspace are derived from the motor nameplate or motor parameter identification results. The equivalent phase resistance of the motor stator is given, and its value is derived from the motor nameplate or parameter identification results. A proportional-integral (PI) controller is configured using the calculated PI coefficients.

[0073] S205, real-time acquisition of five-phase stator current and rotor position information during motor operation and transformation to obtain d 1- q 1. Measured components of the fundamental subspace and d 3- q The measured components of the 3rd harmonic subspace, combined with the preset given reference current input current decoupling controller, are used to obtain the reference regulating voltage through the proportional-integral regulator, the impedance reshaping voltage through the impedance reshaping channel, and the reference compensation voltage through the coupling damping compensation channel.

[0074] S206 calculates the target reference voltage for each coordinate axis in the two subspaces based on the impedance reshaping voltage, reference compensation voltage, and reference adjustment voltage, and converts the target reference voltage into drive signals for the inverter switching devices to drive the five-phase permanent magnet synchronous motor.

[0075] This embodiment performs equivalent processing on the system delay component through stability boundary calculation, resulting in... d 1- q 1. Fundamental Subspace and d 3- qThe stability boundary of the 3rd harmonic subspace is determined. Then, based on the Bode plot frequency domain analysis of the disturbance suppression transfer function, the optimal combination of virtual resistance, virtual inductance and auxiliary attenuation gain is selected. Based on the Bode plot frequency domain analysis of the reference tracking closed-loop transfer function, the optimal current loop control bandwidth is selected and the proportional-integral coefficients are calculated to construct the current decoupling controller. By transforming the complex system delay effects into concise mathematical constraints, the theoretical difficulty of parameter design is reduced. Furthermore, independent boundaries are calculated for the fundamental and harmonic subspaces, fully considering the impact of differences in equivalent resistance and inductance parameters in different subspaces of the five-phase permanent magnet synchronous motor on stability, resulting in more precise parameter tuning. Through Bode plot optimization of the disturbance suppression transfer function, targeted suppression of specific harmonic frequencies such as the 3rd, 7th, and 9th harmonics is achieved. Compared with traditional active damping methods, this maximizes the suppression depth of the target harmonics while ensuring system stability. Through Bode plot optimization of the reference tracking closed-loop transfer function, the closed-loop cutoff frequency is maximized while ensuring phase margin, enabling the current loop to achieve the highest possible dynamic response speed. Moreover, this optimization process is independent of the selection of impedance reshaping parameters, further consolidating the effect of two-degree-of-freedom decoupled control.

[0076] Example 3

[0077] Figure 4 This is a flowchart of a harmonic current control method for a five-phase permanent magnet synchronous motor based on impedance reshaping, as described in Embodiment 3 of the present invention. This embodiment is an optimization based on the above embodiment. In this embodiment, S103 is specifically optimized as follows:

[0078] Real-time acquisition of five-phase stator current and rotor position information during operation of a five-phase permanent magnet synchronous motor, and obtaining data based on vector space decoupling transformation. d 1- q 1. Measured components of the fundamental subspace and d 3- q Measured components of the 3rd harmonic subspace;

[0079] The measured components of the two subspaces and the preset reference current are input into the proportional-integral regulator to obtain the reference regulating voltage.

[0080] The reference adjustment voltage and the measured components of the two subspaces are input to the impedance reshaping channel and the coupling damping compensation channel to generate the impedance reshaping voltage used to suppress system harmonic disturbances and the reference compensation voltage used to eliminate the coupling effect of impedance reshaping on tracking performance, respectively.

[0081] Accordingly, the harmonic current control method for a five-phase permanent magnet synchronous motor based on impedance reshaping provided in this embodiment specifically includes:

[0082] S301 collects the five-phase current of a five-phase permanent magnet synchronous motor and obtains the total delay information of the motor control system, decomposing the five-phase current into... d 1- q 1. Fundamental subspace components and d 3- q The three harmonic subspace components are calculated, and the stability boundary information of the two subspaces is calculated based on the total delay information.

[0083] S302 generates multiple sets of virtual impedance and auxiliary attenuation gain parameter combinations for two subspaces based on stability boundary information. At the same time, it generates multiple current loop control bandwidths based on the motor's nameplate parameters and actual input current. Then, based on Bode plot frequency domain analysis, it selects an optimal parameter combination and an optimal current loop control bandwidth, and then calculates the proportional-integral coefficients to construct the impedance reshaping channel, coupling damping compensation channel, and proportional-integral regulator of the current decoupling controller.

[0084] S303 collects the five-phase stator current and rotor position information in real time during the operation of the five-phase permanent magnet synchronous motor, and obtains the result based on vector space decoupling transformation. d 1- q 1. Measured components of the fundamental subspace and d 3- q Measured components of the 3rd harmonic subspace.

[0085] The five-phase stator current of the five-phase permanent magnet synchronous motor during closed-loop operation is collected in real time by a current sensor. i a , i b , i c , i d , i e The rotor position information θ is acquired in real time through position sensors (such as encoders or resolvers). Similarly, based on the vector space decoupling transformation of Clark and Park transforms, the measured five-phase stator current is mapped to... d 1- q 1. Measured components of the fundamental subspace and d 3- q The measured components of the 3rd harmonic subspace are used to obtain the current state of the five-phase permanent magnet synchronous motor. d 1. q 1. d 3. q Actual current components on the 3 axes. d 1- q The fundamental subspace mainly corresponds to the fundamental current component of the motor, and is used to generate electromagnetic torque. d 3- qThe third harmonic subspace corresponds to the harmonic current components.

[0086] S304 inputs the measured components of the two subspaces and the preset given reference current into the proportional-integral regulator to obtain the reference regulating voltage.

[0087] Given a pre-set reference current, for the two subspaces d 1 For the axis, the given reference current is usually set to 0 (using the id=0 control strategy), for q 1 For the shaft, the given reference current is determined by the output of the outer loop PI regulator (proportional-integral regulator). d 3 , q 3 The reference current is set to 0 for both axes to suppress harmonics, and is used together with the measured components of the two subspaces as input data for the current decoupling controller.

[0088] Optionally, the current difference between the given reference current and the measured components of the two subspaces is calculated as the current tracking error, and the current tracking error is input into the proportional-integral regulator to obtain the reference regulating voltage.

[0089] Current tracking error e i This is the difference between the given value and the measured value, representing the current tracking error. e i The input is calculated based on the proportional-integral regulator configured according to the aforementioned proportional and integral coefficients, and the output is a reference regulated voltage. u PI This reference regulation voltage represents the basic control quantity required by the system to track a given current.

[0090] S305 takes the reference adjustment voltage and the measured components of the two subspaces, inputs them to the impedance reshaping channel and the coupling damping compensation channel, and generates the impedance reshaping voltage for suppressing system harmonic disturbances and the reference compensation voltage for eliminating the coupling effect of impedance reshaping on tracking performance, respectively.

[0091] However, relying solely on a PI controller is insufficient to effectively suppress harmonic disturbances across a wide frequency range. Furthermore, the introduction of impedance reshaping alters the closed-loop poles of the system due to the virtual impedance, impacting dynamic tracking performance. Therefore, an impedance reshaping channel and a coupling damping compensation channel can be used. The reference regulation voltage and the measured components of the two subspaces can be input, while the impedance reshaping channel uses the measured components of the two subspaces as input. The impedance reshaping voltage is calculated using the total equivalent auxiliary impedance function. U viIt is used to reshape the port impedance and increase system damping; the coupled damping compensation channel takes the reference adjusted voltage and the measured components of the two subspaces as inputs, and calculates the reference compensation voltage through the coupled damping compensation function. C d It is used to counteract the coupling effect of the impedance reshaping stage on the reference tracking channel.

[0092] In one optional implementation of this embodiment, the impedance reshaping voltage is calculated using the total equivalent auxiliary impedance function in the impedance reshaping channel, and the reference compensation voltage is calculated using the coupling damping compensation function in the coupling damping compensation channel. The impedance reshaping voltage... U vi The calculation formula is:

[0093] The reference compensation voltage C d The calculation formula is:

[0094]

[0095] in, R v For virtual resistance, L v For virtual inductance, G aux To assist in attenuating gain, L d,q For the motor in d 1- q 1. Fundamental Subspace and d 3- q The actual inductance parameters corresponding to the 3rd harmonic subspace. For the motor in d 1- q 1. Fundamental Subspace and d 3- q The equivalent inductance parameters corresponding to the 3rd harmonic subspace are derived from the motor nameplate or motor parameter identification results. R s Actual phase resistance of the motor stator. This is the equivalent phase resistance of the motor stator, and its value is derived from the motor nameplate or motor parameter identification results. K c This represents the optimal current loop control bandwidth. s For differential operators, i d,q For the measured current components on the corresponding coordinate axes, U Gc The reference voltage is used for adjustment. In the two calculation formulas above... R v , L v ,G aux The three parameters are the optimal combination obtained from the aforementioned calculations, used to configure the impedance reshaping channel and coupling damping compensation channel of the current decoupling controller. Impedance characteristics are reshaped by connecting a virtual impedance in series with a virtual resistor and a virtual inductor at the motor port, increasing the system's equivalent damping. This causes a voltage drop when the disturbance current flows through this impedance, reducing the amplitude response of the motor system to external disturbances and improving the system's ability to suppress harmonic disturbances. The auxiliary attenuation gain, as a gain adjustment factor, is used to further optimize the attenuation depth in specific frequency bands, such as... Figure 5 The diagram shows the block diagram of a current decoupling controller based on impedance reshaping. When harmonic currents occur, a corresponding reverse voltage is immediately generated through these two channels to suppress them, achieving a feedback-based active damping mechanism. While the impedance reshaping channel enhances disturbance rejection, the virtual impedance it introduces simultaneously alters the system's closed-loop transfer function, causing changes in reference tracking performance (such as overshoot and settling time), i.e., coupling occurs. To reduce the impact of this coupling, a reference compensation voltage is calculated using a coupling damping compensation channel and added during the final target reference voltage synthesis. This counteracts the influence of the impedance reshaping voltage on the pole positions in the reference tracking transfer function, ensuring that the system's reference tracking transfer function depends only on the motor's nominal parameters and the PI regulator parameters, and is independent of the virtual impedance parameters.

[0096] S306 calculates the target reference voltage for each coordinate axis in the two subspaces based on the impedance reshaping voltage, reference compensation voltage, and reference adjustment voltage, and converts the target reference voltage into drive signals for the inverter switching devices to drive the five-phase permanent magnet synchronous motor.

[0097] At the end of each control cycle, the target reference voltage output by the current decoupling controller is obtained by adding the impedance reshaping voltage and the reference compensation voltage, and then subtracting it from the reference adjustment voltage. The calculation formula is as follows:

[0098]

[0099] in, u PI Adjust the reference voltage. C d For reference compensation voltage, U vi The impedance is reshaped into voltage. Then, an inverse Park transformation is performed on the target reference voltage for each coordinate axis, restoring it from a synchronous rotating coordinate system to a stationary two-phase orthogonal coordinate system. Finally, this is input to the space vector pulse width modulation (SVPWM) algorithm to obtain the inverter's duty cycle in the next control cycle, and generates the corresponding PWM pulse drive signal sequence to drive the motor.

[0100] Specifically, the reference compensation voltage is added to the impedance reshaping voltage, and then the difference is taken from the reference adjustment voltage to obtain the target reference voltage for each coordinate axis in the two subspaces.

[0101] At the output of the current decoupling controller, the three calculated voltage components are synthesized. The reference regulation voltage is the main control quantity generated by the proportional-integral controller based on the current error, used to provide the basic voltage required for motor operation. The impedance reshaping voltage is used to provide additional system damping to suppress harmonics. The reference compensation voltage is used to offset the coupling effect of the impedance reshaping stage on command tracking. Since the impedance reshaping voltage and the reference compensation voltage are essentially a correction or compensation of the reference regulation voltage, the decoupling control strategy is reflected in the target reference voltage through addition and subtraction operations. This ensures that the motor can still accurately track the given current command while obtaining strong damping and harmonic suppression capabilities, thus achieving decoupled and independent adjustment of reference tracking performance and disturbance suppression performance.

[0102] Perform an inverse Park transform on the target reference voltage for each coordinate axis to obtain α 1- β 1 and α 3- β The target reference voltage in the 3-coordinate system is used to calculate the duty cycle of each bridge arm of the inverter using space vector pulse width modulation technology, and generate PWM pulse signals to drive the five-phase permanent magnet synchronous motor.

[0103] Since the target reference voltage is a DC quantity calculated in a synchronous rotating coordinate system, while the inverter requires an AC quantity in a stationary coordinate system for drive, an inverse Park transformation is necessary. d 1 -q 1 Fundamental subspace and d 3 -q 3 The target reference voltage in the harmonic subspace is transformed to α 1 -β 1 and α 3 -β 3 In a stationary coordinate system, two sets of orthogonal voltage components are obtained. Then, using Space Vector Pulse Width Modulation (SVPWM) technology, based on the target voltage vector in the stationary coordinate system and the DC bus voltage, the duty cycle of each bridge arm switch of the inverter is calculated. By rationally arranging the operating timing of the switches, the inverter output approximates the desired voltage waveform. Finally, a PWM pulse signal is generated based on the calculated duty cycle to control the on / off state of the inverter (such as IGBTs), generating the required current in the stator windings of the five-phase permanent magnet synchronous motor, driving the motor to run smoothly. Figure 6 The diagram shows the structure of a five-phase permanent magnet synchronous motor drive system.

[0104] This embodiment obtains the result by real-time acquisition and transformation of the five-phase stator current. d 1 -q 1 Fundamental subspace and d 3 -q 3 The measured current component in the harmonic subspace, combined with a given reference current input, is used to construct a current decoupling controller. Through the coordinated action of its internal proportional-integral (PI) regulator, impedance reshaping channel, and coupling damping compensation channel, the target reference voltage is finally obtained, completing the control voltage calculations for each coordinate axis. This ensures that the decoupled system's reference tracking transfer function depends only on the motor's nominal parameters and the PI regulator parameters, and is independent of virtual resistance, virtual inductance, and auxiliary attenuation gain. The PI regulator can be independently tuned according to dynamic response requirements, and the impedance reshaping parameters can be independently tuned according to harmonic suppression requirements, forming a two-degree-of-freedom parameter adjustment that does not interfere with each other, greatly reducing the complexity of system debugging. The simultaneous introduction of virtual resistance and virtual inductance in the impedance reshaping channel enables the system to have good suppression capabilities for both low-frequency and high-frequency harmonics, achieving harmonic attenuation over a wide frequency range. The coupling damping compensation channel uses the reference regulating voltage and measured current feedback as inputs, and its compensation function is designed to match the impedance reshaping channel. This eliminates coupling effects without introducing additional noise or stability risks, ensuring the purity and reliability of the control system and achieving effective decoupling.

[0105] Example 4

[0106] To verify the effectiveness and superiority of the impedance reshaping-based harmonic current control method for five-phase permanent magnet synchronous motors proposed in this invention, an experimental platform for a five-phase permanent magnet synchronous motor drive system was built for testing. This experimental platform mainly consists of a five-phase permanent magnet synchronous motor and a three-phase permanent magnet synchronous motor (serve as a load), coaxially connected. The load torque is controlled by adjusting a variable resistor connected to the output terminal of the load motor. In the experiment, a conventional PI regulator was used for the outer speed loop controller, while the control strategy proposed in this invention was used for the inner current loop. The experimental results are as follows: Figures 7 to 9 As shown.

[0107] First, the harmonic suppression capability of the method of the present invention under steady-state operating conditions is verified, such as... Figure 7The figure shows the harmonic suppression experimental waveforms of a five-phase permanent magnet synchronous motor under steady-state conditions of 200 r / min and 4 N·m load torque. As can be seen from the figure, after applying the method of this invention, the D-phase current waveform exhibits high-quality sinusoidal characteristics, and the low-order harmonics caused by inverter nonlinearity are significantly reduced. Fast Fourier Transform (FFT) analysis shows that the total harmonic distortion (THD) of the D-phase current is only 2.84%. This excellent steady-state performance verifies that the impedance reshaping channel constructed in this invention can effectively reshape the motor port impedance characteristics, significantly increasing the equivalent impedance of the system at harmonic frequencies, thereby achieving deep suppression of harmonic currents.

[0108] Secondly, the decoupling control effect of the method of the present invention under dynamic operating conditions is verified, such as... Figure 8 The figure shows the dynamic experimental results of a five-phase permanent magnet synchronous motor accelerating from 400 r / min to 700 r / min in step increments under a maximum load of 5.8 N·m. During motor acceleration, the frequency of harmonic disturbances continuously changes with the increase of speed, posing a severe challenge to the dynamic adaptability of the controller. However, as can be seen from the experimental waveform, the THD of the D-phase current controlled by the method of this invention remains within 3.58% throughout the entire acceleration process, and the current waveform transitions smoothly without significant distortion or oscillation. This result indicates that, thanks to the design of the coupling damping compensation channel, the system successfully eliminates the coupling effect of the impedance reshaping stage on the reference tracking performance, enabling the motor to maintain a high-quality steady-state current output even during dynamic speed changes. This verifies the effectiveness of the core mechanism of independently adjusting the reference tracking performance and disturbance suppression performance of this invention.

[0109] Finally, to visually demonstrate the advantages of this invention over existing technologies, such as... Figure 9 As shown, through comparative experiments, under the condition of a maximum load of 3.3 N·m and a motor speed increasing from 200 r / min to 400 r / min, the experimental data of traditional proportional-integral (PI) control, traditional proportional-resonant (PR) control, traditional active damping control, and the method of this invention were compared. Figure 9 (a) is the experimental waveform diagram of traditional proportional-integral control under this operating condition. Figure 9 (b) shows the experimental waveforms of the traditional proportional resonant control under this operating condition. Figure 9 (c) shows the experimental waveforms of traditional active damping control under this operating condition. Figure 9(d) shows the experimental waveforms of the method of the present invention under this operating condition. Experimental data shows that: traditional PI control, limited by its finite bandwidth, has the worst effect on suppressing AC disturbances, with a current THD of approximately 15.42% before acceleration and a high THD of 13.84% after acceleration; traditional PR control, although it has a suppressive effect on harmonics of specific frequencies, is quite sensitive to frequency changes, with a current THD of approximately 5.14% before acceleration, but deteriorating to 6.57% after acceleration due to the deviation of the resonant point; traditional active damping control, due to the single-degree-of-freedom coupling limitation, sacrifices dynamic performance while improving damping, with a current THD of approximately 6.39% before acceleration and rising to 8.08% after acceleration. In contrast, the method of the present invention shows a significant advantage under the same operating condition, with a current THD of approximately 2.97% before acceleration and approximately 3.08% after acceleration. The comparative results clearly demonstrate that the method of the present invention is almost unaffected by changes in rotational speed, and its harmonic suppression level and robustness are significantly better than existing comparative schemes. By constructing a two-degree-of-freedom control architecture and combining virtual impedance and auxiliary attenuation gain determined through parameter optimization, harmonic suppression in a wide frequency domain is achieved. Simultaneously, the coupling damping compensation mechanism ensures that the dynamic response speed remains unaffected, thus solving the technical challenge of balancing disturbance rejection performance and tracking performance in traditional methods. This significantly reduces the multi-harmonic content in the stator current of a five-phase permanent magnet synchronous motor and maintains robust harmonic suppression performance even during dynamic speed changes.

[0110] Example 5

[0111] Figure 10 This is a schematic diagram of a harmonic current control device for a five-phase permanent magnet synchronous motor based on impedance reshaping, as described in Embodiment 5 of the present invention. In this embodiment, the harmonic current control device for a five-phase permanent magnet synchronous motor based on impedance reshaping includes:

[0112] The stability boundary calculation module 810 is used to decompose the five-phase currents of the five-phase permanent magnet synchronous motor into... d 1- q 1. Fundamental subspace components and d 3- q The three harmonic subspace components are calculated, and the stability boundary information of the two subspaces is calculated based on the total delay information of the motor control system.

[0113] The frequency domain analysis optimization module 820 is used to select an optimal combination of parameters and optimal current loop control bandwidth based on Bode plot frequency domain analysis from multiple sets of virtual impedance and auxiliary attenuation gain parameter combinations generated based on stability boundary information, and from multiple current loop control bandwidths generated based on motor nameplate parameters and actual input current, and to calculate proportional-integral coefficients to construct a current decoupling controller.

[0114] The current decoupling control module 830 is used to collect the five-phase stator current and rotor position information of the motor in real time and transform them into two subspace measured components. Combined with the preset given reference current input current decoupling controller, the reference adjustment voltage, impedance reshaping voltage and reference compensation voltage are obtained.

[0115] The pulse width modulation drive module 840 is used to calculate the target reference voltage of each coordinate axis in the two subspaces based on the impedance reshaping voltage, the reference compensation voltage, and the reference adjustment voltage, and convert it into drive signals for the inverter switching devices to drive the motor.

[0116] The current decoupling control module is a current decoupling controller, which includes a proportional-integral regulator, a coupling damping compensation channel, and an impedance reshaping channel.

[0117] In this embodiment, the stability boundary calculation module comprehensively considers the total delay information of the motor control system to calculate the stability boundary of the two subspaces. The frequency domain analysis optimization module finds the optimal parameter combination and the optimal current loop control bandwidth within the stability boundary to construct a current decoupling controller. The current decoupling control module collects the current and rotor position of the motor in real time and combines them with the preset given reference current to input the current decoupling controller. The pulse width modulation drive module calculates the target reference voltage based on the output of the current decoupling controller and converts it into a drive signal to drive the motor. The impedance reshaping channel, reshaped by optimal parameter combination, effectively reconstructs the port impedance characteristics of the motor, effectively weakening the low-frequency and high-frequency composite disturbances caused by the inverter's nonlinear dead zone and tube voltage drop, achieving deep suppression of multiple harmonic currents in a wide frequency domain, and reducing the current harmonic distortion rate. The two-degree-of-freedom control structure, composed of the coupled damping compensation channel, the impedance reshaping channel, and the proportional-integral regulator, eliminates the adverse effects of active damping technology on the current loop PI command tracking performance, achieving decoupled independent adjustment of dynamic response speed and disturbance rejection capability. By introducing the system's inherent delay characteristics into the characteristic equation, the accuracy of stability boundary analysis can be improved, avoiding high-frequency instability caused by virtual damping, and enhancing the robustness and reliability of the control algorithm.

[0118] The harmonic current control device for a five-phase permanent magnet synchronous motor based on impedance reshaping provided in this embodiment of the invention can execute the harmonic current control method for a five-phase permanent magnet synchronous motor based on impedance reshaping provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the method.

[0119] Example 6

[0120] Figure 11 This is a structural diagram of an electronic device according to Embodiment Six of the present invention. Figure 11 A block diagram is shown of an exemplary electronic device 12 suitable for implementing embodiments of the present invention. Figure 11The electronic device 12 shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of the present invention.

[0121] like Figure 11 As shown, the electronic device 12 is represented in the form of a general-purpose computing device. The components of the electronic device 12 may include, but are not limited to: one or more processors or processing units 16, system memory 28, and bus 18 connecting different system components (including system memory 28 and processing unit 16).

[0122] Bus 18 represents one or more of several bus architectures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor, or a local bus using any of the various bus architectures. For example, these architectures include, but are not limited to, the Industry Standard Architecture (ISA) bus, the Micro Channel Architecture (MAC) bus, the Enhanced ISA bus, the Video Electronics Standards Association (VESA) local bus, and the Peripheral Component Interconnect (PCI) bus.

[0123] Electronic device 12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by electronic device 12, including volatile and non-volatile media, removable and non-removable media.

[0124] System memory 28 may include computer system readable media in the form of volatile memory, such as RAM 30 and / or cache 32. Electronic device 12 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, storage system 34 may be used to read and write non-removable, non-volatile magnetic media ( Figure 11 Not shown; usually referred to as a "hard drive"). Although Figure 11 Not shown, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk") and an optical disk drive for reading and writing to a removable non-volatile optical disk (e.g., a CD-ROM, DVD-ROM, or other optical media) may be provided. In these cases, each drive may be connected to bus 18 via one or more data media interfaces. System memory 28 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the embodiments of the present invention.

[0125] A program / utility 40 having a set (at least one) of program modules 42 may be stored, for example, in system memory 28. Such program modules 42 include, but are not limited to, an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include an implementation of a network environment. Program modules 42 typically perform the functions and / or methods described in the embodiments of the present invention.

[0126] Electronic device 12 can also communicate with one or more external devices 14 (e.g., keyboard, pointing device, display 24, etc.), and with one or more devices that enable a user to interact with the electronic device 12 / server / computer, and / or with any device that enables the electronic device 12 to communicate with one or more other computing devices (e.g., network card, modem, etc.). This communication can be performed through I / O interface 22. Furthermore, electronic device 12 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 20. Figure 11 As shown, network adapter 20 communicates with other modules of electronic device 12 via bus 18. It should be understood that, although... Figure 11 As not shown, other hardware and / or software modules may be used in conjunction with electronic device 12, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0127] The processing unit 16 executes various functional applications and data processing by running programs stored in the system memory 28, such as implementing the harmonic current control method for a five-phase permanent magnet synchronous motor based on impedance reshaping provided in the embodiments of the present invention.

[0128] Example 7

[0129] Embodiment 7 of the present invention also provides a storage medium containing computer-executable instructions, which, when executed by a computer processor, are used to perform the harmonic current control method for a five-phase permanent magnet synchronous motor based on impedance reshaping as provided in the above embodiments.

[0130] The computer storage medium of this invention can be any combination of one or more computer-readable media. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0131] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0132] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including—but not limited to—wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0133] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0134] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A harmonic current control method for a five-phase permanent magnet synchronous motor based on impedance reshaping, characterized in that, include: S101 collects the five-phase current of the five-phase permanent magnet synchronous motor and obtains the total delay information of the motor control system, decomposing the five-phase current into... d 1- q 1. Fundamental subspace components and d 3- q The three harmonic subspace components are calculated, and the stability boundary information of the two subspaces is calculated based on the total delay information. S101 includes: The five-phase currents of a five-phase permanent magnet synchronous motor are collected and subjected to vector space decoupling transformation to obtain... d 1- q 1. Fundamental subspace components and d 3- q 3rd harmonic subspace components; Based on the motor system sampling delay, PWM delay, and motor controller parameters in the total delay information, calculate the parameters that enable the motor to... d 1- q 1. Fundamental Subspace and d 3- q The control parameter range and bandwidth limitation range of the current-controlled closed-loop system operating stably in the 3rd harmonic subspace form the stability boundary information of the two subspaces. S102 generates multiple sets of virtual impedance and auxiliary attenuation gain parameter combinations for two subspaces based on stability boundary information. At the same time, it generates multiple current loop control bandwidths based on the motor nameplate parameters and actual input current. Then, based on Bode plot frequency domain analysis, it selects a set of optimal parameter combinations and optimal current loop control bandwidths, and then calculates proportional-integral coefficients to construct the impedance reshaping channel, coupling damping compensation channel, and proportional-integral regulator of the current decoupling controller. S103, real-time acquisition of five-phase stator current and rotor position information during motor operation and transformation to obtain d 1- q 1. Measured components of the fundamental subspace and d 3- q The measured components of the 3rd harmonic subspace, combined with the preset given reference current input current decoupling controller, obtain the reference regulating voltage through the proportional-integral regulator, obtain the impedance reshaping voltage through the impedance reshaping channel, and obtain the reference compensation voltage through the coupling damping compensation channel. S104 calculates the target reference voltage for each coordinate axis in the two subspaces based on the impedance reshaping voltage, reference compensation voltage, and reference adjustment voltage, and converts the target reference voltage into drive signals for the inverter switching devices to drive the five-phase permanent magnet synchronous motor. S104 includes: The target reference voltage for each coordinate axis in the two subspaces is obtained by adding the reference compensation voltage and the impedance reshaping voltage, and then subtracting it from the reference adjustment voltage. Perform an inverse Park transform on the target reference voltage for each coordinate axis to obtain α 1- β 1 and α 3- β The target reference voltage in the 3-coordinate system is used to calculate the duty cycle of each bridge arm of the inverter using space vector pulse width modulation technology, and generate PWM pulse signals to drive the five-phase permanent magnet synchronous motor.

2. The method according to claim 1, characterized in that, S102 includes: Based on the stability boundary information, multiple sets of parameter combinations including virtual resistance, virtual inductance and auxiliary attenuation gain are generated for each subspace. A motor system disturbance suppression transfer function including virtual resistance, virtual inductance and auxiliary attenuation gain is constructed. The amplitude-frequency characteristics of the transfer function are analyzed based on the Bode plot frequency domain. The optimization objective is to minimize the amplitude gain at the target harmonic frequency, and a set of optimal parameter combinations is selected. The equivalent resistance and equivalent inductance of the motor are calculated based on the nameplate parameters of the motor. A closed-loop transfer function between the current loop reference current and the actual current is constructed in combination with the current decoupling controller to reflect the input of the motor. The current loop control bandwidth is configured as an adjustable parameter. The amplitude-frequency characteristics and phase-frequency characteristics of the closed-loop transfer function are analyzed based on the Bode plot frequency domain to obtain the phase margin and amplitude change of the motor system. The frequency with the largest closed-loop cutoff frequency and no significant resonance peak is selected as the optimal current loop control bandwidth according to the preset phase margin. By configuring the impedance reshaping channel and the coupling damping compensation channel using the optimal parameter combination, and by calculating the proportional-integral coefficient using the optimal current loop control bandwidth and configuring the proportional-integral regulator, a current decoupling controller is formed, which includes the impedance reshaping channel, the coupling damping compensation channel and the proportional-integral regulator.

3. The method according to claim 1, characterized in that, S103 includes: Real-time acquisition of five-phase stator current and rotor position information during operation of a five-phase permanent magnet synchronous motor, and obtaining data based on vector space decoupling transformation. d 1- q 1. Measured components of the fundamental subspace and d 3- q Measured components of the 3rd harmonic subspace; The measured components of the two subspaces and the preset reference current are input into the proportional-integral regulator to obtain the reference regulating voltage. The reference adjustment voltage and the measured components of the two subspaces are input to the impedance reshaping channel and the coupling damping compensation channel to generate the impedance reshaping voltage used to suppress system harmonic disturbances and the reference compensation voltage used to eliminate the coupling effect of impedance reshaping on tracking performance, respectively.

4. The method according to claim 3, characterized in that, S103 further includes: The current difference between the given reference current and the measured components of the two subspaces is calculated as the current tracking error, and the current tracking error is input into the proportional-integral regulator to obtain the reference regulating voltage. The impedance reshaping voltage is calculated using the total equivalent auxiliary impedance function in the impedance reshaping channel, and the reference compensation voltage is calculated using the coupling damping compensation function in the coupling damping compensation channel.

5. The method according to claim 4, characterized in that, S103 further includes: The impedance reshaping voltage U vi The calculation formula is: The reference compensation voltage C d The calculation formula is: in, R v For virtual resistance, L v For virtual inductance, G aux To assist in attenuating gain, L d,q For the motor in d 1- q 1. Fundamental Subspace and d 3- q The actual inductance parameters corresponding to each coordinate axis in the 3rd harmonic subspace. For the motor in d 1- q 1. Fundamental Subspace and d 3- q The equivalent inductance parameters of each coordinate axis in the 3rd harmonic subspace. R s This represents the actual phase resistance of the motor stator. This is the equivalent phase resistance of the motor stator. K c This represents the optimal current loop control bandwidth. s For differential operators, i d,q For the measured current components on the corresponding coordinate axes, U Gc The reference voltage is adjusted.

6. A harmonic current control device for a five-phase permanent magnet synchronous motor based on impedance reshaping, used to implement the harmonic current control method for a five-phase permanent magnet synchronous motor based on impedance reshaping as described in any one of claims 1-5, characterized in that, include: The stability boundary calculation module is used to decompose the five-phase currents of the five-phase permanent magnet synchronous motor into... d 1- q 1. Fundamental subspace components and d 3- q The three harmonic subspace components are calculated, and the stability boundary information of the two subspaces is calculated based on the total delay information of the motor control system. The frequency domain analysis optimization module is used to select an optimal combination of parameters and optimal current loop control bandwidth based on Bode plot frequency domain analysis from multiple sets of virtual impedance and auxiliary attenuation gain parameter combinations generated based on stability boundary information, and from multiple current loop control bandwidths generated based on motor nameplate parameters and actual input current, and to calculate proportional-integral coefficients to construct a current decoupling controller. The current decoupling control module is used to collect the five-phase stator current and rotor position information of the motor in real time and transform them into two subspace measured components. Combined with the preset given reference current input current decoupling controller, the reference adjustment voltage, impedance reshaping voltage and reference compensation voltage are obtained. The pulse width modulation drive module is used to calculate the target reference voltage of each coordinate axis in the two subspaces based on the impedance reshaping voltage, reference compensation voltage, and reference adjustment voltage, and convert it into drive signals for the inverter switching devices to drive the motor. The current decoupling control module is a current decoupling controller, which includes a proportional-integral regulator, a coupling damping compensation channel, and an impedance reshaping channel.

7. An electronic device, characterized in that, The electronic device includes: One or more processors; Storage device for storing one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors implement the harmonic current control method for a five-phase permanent magnet synchronous motor based on impedance reshaping as described in any one of claims 1-5.

8. A storage medium containing computer-executable instructions, characterized in that, The computer-executable instructions, when executed by a computer processor, are used to perform the harmonic current control method for a five-phase permanent magnet synchronous motor based on impedance reshaping as described in any one of claims 1-5.

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