Motor control method, device and equipment and storage medium

Abstract

The invention discloses a motor control method and device, equipment and a storage medium, and relates to the field of motor control, and the method comprises the steps: adding a high-frequency voltage injection component into a target control voltage instruction, carrying out the processing of a collected three-phase current signal of a motor, extracting a high-frequency current signal corresponding to the high-frequency voltage injection component, and obtaining a high-frequency current signal corresponding to the high-frequency voltage injection component; a cross saturation correction coefficient is introduced to compensate an interference component generated by a cross saturation effect of d-axis inductance and q-axis inductance of the motor body in the high-frequency current signal, so that a position error signal is accurately determined, a more accurate rotating speed observation value and a more accurate rotor position observation value are obtained, the motor is controlled, and the accuracy of the motor is improved. According to the invention, the problems of inaccurate estimation of the rotor position and reduction of the load capacity of zero-frequency and low-frequency intervals caused by insufficient consideration of the cross saturation effect in the prior art are solved, and the effect of improving the stability and reliability of the motor during low-frequency operation is achieved.

Description

Technical Field

[0001] This application relates to the field of motor control, and in particular to a motor control method, apparatus, device, and storage medium. Background Technology

[0002] Synchronous reluctance motors (SRRMs) possess advantages such as low heat generation, high temperature resistance, high efficiency, and low cost due to their rotors having no permanent magnets or using only ferrite. They hold significant potential for energy-saving retrofits in applications such as fans and pumps. Open-loop vector control of SRRMs relies on accurate rotor position estimation. However, existing control schemes do not fully consider the saturation characteristics of the d-axis and q-axis inductances of the SRRM and the cross-saturation effect between them in their position estimation algorithms. This leads to a mismatch between the established observation model and the motor's inherent characteristics, introducing rotor position estimation errors. Consequently, the system's load-carrying capacity decreases in the zero-frequency and low-frequency ranges, affecting the operational stability and reliability of the SRRM.

[0003] Therefore, how to provide a solution to the above-mentioned technical problems is a problem that needs to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of this application is to provide a motor control method, device, equipment, and storage medium to at least solve the problems in the related art, such as inaccurate rotor position estimation and reduced load-carrying capacity in the zero-frequency and low-frequency ranges due to insufficient consideration of cross saturation effects.

[0005] To solve the above-mentioned technical problems, this application provides a motor control method, including:

[0006] Determine the three-phase current signal of the motor under the target control voltage command; the target control voltage command includes a high-frequency voltage injection component.

[0007] The three-phase current signal is processed to obtain a high-frequency current signal corresponding to the high-frequency voltage injection component;

[0008] The position error signal is determined based on the high-frequency current signal and the cross-saturation correction coefficient; the cross-saturation correction coefficient is used to compensate for the interference component in the high-frequency current signal, and the interference component is obtained based on the cross-saturation effect between the d-axis inductance and the q-axis inductance of the motor.

[0009] The observed speed and rotor position are obtained based on the position error signal, and the motor is controlled based on the observed speed and rotor position.

[0010] Optionally, the three-phase current signal is processed to obtain a high-frequency current signal corresponding to the high-frequency voltage injection component, including:

[0011] The three-phase current signal is converted into a stationary current signal in a two-phase stationary coordinate system;

[0012] The static current signal is transformed to the observation coordinate system to obtain the observation current signal in the observation coordinate system.

[0013] Extract the intermediate current signal generated by the high-frequency voltage injection component from the observed current signal;

[0014] The high-frequency current signal is obtained based on the intermediate current signal.

[0015] Optionally, extracting the intermediate current signal generated by the high-frequency voltage injection component from the observed current signal includes:

[0016] The fundamental current component in the observed current signal is filtered out using a filter, and the current component corresponding to the high-frequency voltage injection component is retained as an intermediate current signal.

[0017] Optionally, the motor control method further includes:

[0018] Obtain the d-axis inductance value, q-axis inductance value, and mutual inductance value between the d-axis and q-axis of the motor;

[0019] The cross saturation correction coefficient is obtained based on the d-axis inductance value, the q-axis inductance value, and the mutual inductance value.

[0020] Optionally, the high-frequency current signal includes a high-frequency current component of the injection axis and a high-frequency current component of the compensation axis, wherein the injection axis is the axis into which the high-frequency voltage injection component is injected, and the compensation axis is an axis orthogonal to the injection axis.

[0021] The process of determining the position error signal based on the high-frequency current signal and the cross-saturation correction coefficient includes:

[0022] Based on the cross-saturation correction coefficient and the high-frequency current component of the injection axis, the cross-saturation interference compensation amount is obtained.

[0023] The position error signal is obtained based on the cross-saturation interference compensation amount and the high-frequency current component of the compensation axis.

[0024] Optionally, the position error signal is obtained based on the cross-saturation interference compensation amount and the high-frequency current component of the compensation axis, including:

[0025] The high-frequency current component of the compensation axis is compensated based on the cross-saturation interference compensation amount to obtain the initial error signal;

[0026] The position error signal is obtained based on the initial error signal and the first preset coefficient;

[0027] The first preset coefficient is determined based on the high-frequency voltage injection component, the cross-saturation correction coefficient, and the inductance parameters of the motor. The inductance parameters include the inductance value of the injection shaft, the inductance value of the compensation shaft, and the mutual inductance value between the injection shaft and the compensation shaft.

[0028] Optionally, the motor control method further includes:

[0029] Determine the reference cosine signal and the reference voltage amplitude;

[0030] Determine the sign and absolute value of the reference cosine signal;

[0031] The high-frequency voltage injection component is generated based on the larger of the absolute value and the preset minimum amplitude coefficient, the sign, and the reference voltage amplitude.

[0032] This application also provides a motor control device, including:

[0033] The first determining module is used to determine the three-phase current signal of the motor under the target control voltage command; the target control voltage command includes a high-frequency voltage injection component.

[0034] The processing module is used to process the three-phase current signal to obtain a high-frequency current signal corresponding to the high-frequency voltage injection component;

[0035] The second determining module is used to determine the position error signal based on the high-frequency current signal and the cross-saturation correction coefficient; the cross-saturation correction coefficient is used to compensate for the interference component in the high-frequency current signal, and the interference component is obtained based on the cross-saturation effect between the d-axis inductance and the q-axis inductance of the motor.

[0036] The control module is used to obtain the observed speed value and the observed rotor position value according to the position error signal, and to control the motor based on the observed speed value and the observed rotor position value.

[0037] This application also provides an electronic device, including:

[0038] Memory, used to store computer programs;

[0039] A processor for executing the computer program to implement the steps of the motor control method as described in any of the above.

[0040] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the motor control method as described in any of the above claims.

[0041] In this application, by adding a high-frequency voltage injection component to the target control voltage command and processing the collected three-phase current signal of the motor to extract the high-frequency current signal corresponding to the high-frequency voltage injection component, and by introducing a cross-saturation correction coefficient, the interference component in the high-frequency current signal caused by the cross-saturation effect of the d-axis inductance and q-axis inductance of the motor body is compensated, thereby accurately determining the position error signal and obtaining more accurate speed observation and rotor position observation values ​​for motor control. This solves the problem in related technologies where the rotor position estimation is inaccurate and the load-carrying capacity in the zero-frequency and low-frequency ranges is reduced due to insufficient consideration of the cross-saturation effect, thus improving the stability and reliability of the motor during low-frequency operation. Attached Figure Description

[0042] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a flowchart illustrating the steps of a motor control method provided in an embodiment of this application.

[0044] Figure 2 A diagram showing the relationship between various coordinate axes provided in an embodiment of this application;

[0045] Figure 3 This is a schematic diagram of a phase-locked loop provided in an embodiment of this application;

[0046] Figure 4 A block diagram of a high-frequency injection sensorless vector control for a synchronous reluctance motor provided in this application embodiment;

[0047] Figure 5 A schematic diagram of a synchronous reluctance motor under zero-frequency ride current during motoring and generating, and the observed speed value, provided for an embodiment of this application;

[0048] Figure 6 A schematic diagram of rotor position and rotor position prediction under zero-frequency through current for motoring and generating synchronous reluctance motors provided in this application embodiment;

[0049] Figure 7 This is a schematic diagram of the structure of a motor control device provided in this application. Detailed Implementation

[0050] The core of this application is to provide a motor control method, device, equipment, and storage medium to at least solve the problems in related technologies, such as inaccurate rotor position estimation and reduced load-carrying capacity in the zero-frequency and low-frequency ranges due to insufficient consideration of cross-saturation effects.

[0051] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0052] This application provides a motor control method, please refer to... Figure 1 ,include:

[0053] S101: Determine the three-phase current signal of the motor under the target control voltage command; the target control voltage command includes a high-frequency voltage injection component.

[0054] To address the issues of inaccurate rotor position estimation and reduced low-frequency load capacity in sensorless motor control due to insufficient consideration of the cross-saturation effect between the d-axis and q-axis inductances, this embodiment injects a high-frequency voltage injection component into the control voltage. This forms the target control voltage command applied to the three-phase windings of the motor. This high-frequency voltage injection component is a voltage signal with a frequency much higher than the fundamental frequency of the motor, used to excite a high-frequency current response containing rotor position information in the motor stator windings. To extract this high-frequency current response, the actual three-phase current signals generated by the motor under this voltage excitation, i.e., the instantaneous current values ​​of the U-phase, V-phase, and W-phase stator windings, need to be acquired simultaneously.

[0055] The process of acquiring three-phase current signals includes: sampling at least one phase current of the motor according to different sampling methods to directly obtain, calculate, or reconstruct the three-phase current signal of the motor. When injecting a high-frequency voltage injection component, the high-frequency voltage injection component can be applied to the d-axis or q-axis of the observation coordinate system, and then, after coordinate transformation and pulse width modulation, the actual voltage applied to the motor is finally generated.

[0056] This embodiment provides a current data foundation for sensorless control. By injecting high-frequency voltage and acquiring the current response, rotor position information is reflected in the current signal. Accurate acquisition of the three-phase current signal is a prerequisite for subsequent signal processing and position calculation, providing a reliable foundation for achieving high-precision speed and position observation.

[0057] S102: Process the three-phase current signal to obtain the high-frequency current signal corresponding to the high-frequency voltage injection component.

[0058] Since the three-phase current signal contains not only the high-frequency response component generated by the high-frequency voltage injection component, but also the fundamental current component required for normal motor operation and other noise interference components, directly using the original three-phase current signal cannot effectively extract the characteristic information reflecting the rotor position. Therefore, this embodiment processes the three-phase current signal to extract the current signal component in the three-phase current signal that has the same frequency as the high-frequency voltage injection component and is modulated by the rotor position, which is the required high-frequency current signal.

[0059] Processing three-phase current signals includes, but is not limited to: filter-based frequency domain separation methods, such as using high-pass, band-pass, or notch filters to directly filter the three-phase current signal or its transformed signal to retain high-frequency components; or time-domain processing methods based on synchronous demodulation, such as multiplying the three-phase current signal with a reference signal of the same frequency and then filtering it with a low-pass filter to extract the low-frequency error signal containing position information; or separation methods based on coordinate transformation, such as converting the current to a specific coordinate system and using the spectral characteristics of the signal in that coordinate system for separation. The specific scheme selected depends on the high-frequency injection method, system cost, and performance requirements, and this embodiment does not impose specific limitations.

[0060] This embodiment effectively extracts a pure, position-related high-frequency current response from a complex mixed signal by performing targeted processing on the original three-phase current signal, thereby improving the accuracy of rotor position estimation.

[0061] S103: Determine the position error signal based on the high-frequency current signal and the cross-saturation correction coefficient; the cross-saturation correction coefficient is used to compensate for the interference component in the high-frequency current signal, and the interference component is obtained based on the cross-saturation effect between the d-axis inductance and the q-axis inductance of the motor.

[0062] In this embodiment, considering the cross-saturation effect between the d-axis and q-axis inductance of the motor body—that is, a change in current in one axis affects the flux linkage in the other axis—this cross-saturation effect introduces an interference component into the high-frequency current signal, independent of the rotor position. Without compensation, this interference component leads to inaccurate calculated position error signals, thus affecting observation accuracy. Therefore, this embodiment introduces a cross-saturation correction coefficient to compensate for this interference component. This cross-saturation correction coefficient quantitatively characterizes the strength of the cross-saturation effect and can be calculated based on the motor's inductance parameters. By calculating this cross-saturation correction coefficient with the corresponding component in the high-frequency current signal, the interference can be canceled, resulting in a more accurate position error signal.

[0063] By introducing a cross-saturation correction coefficient for targeted compensation, this embodiment effectively eliminates the error caused by the inductance cross-saturation effect on the position observation model, enabling the obtained position error signal to more realistically reflect the deviation between the actual rotor position and the observed position, and significantly improving the position observation accuracy.

[0064] S104: Obtain the observed speed and rotor position values ​​based on the position error signal, and control the motor based on the observed speed and rotor position values.

[0065] For easier understanding, please refer to Figure 2 , Figure 2 A diagram showing the relationship between various coordinate axes is provided in this application embodiment, wherein, For a physical stationary coordinate system, For the physical coordinate system, To observe the coordinate system, This represents the actual rotor position. These are rotor position observations. This is the angular deviation between the observed rotor position and the actual rotor position, which is also the position error signal in this embodiment.

[0066] Considering that the position error signal reflects the observed coordinate system ( ) and physical coordinate system ( The position error signal provides information on the angular deviation between the observed and physical coordinate systems, but this signal itself cannot be directly used for vector control of the motor. Therefore, it is necessary to use a corresponding observer or estimation algorithm to calculate the usable speed and rotor position observations in real time from the position error signal. It can be understood that when the position error signal approaches 0, it indicates that the observed coordinate system is aligned with the physical coordinate system, and at this point, the rotor position observation can represent the true rotor position. The speed and rotor position observations, as feedback quantities, replace the speed and position signals provided by the actual physical sensors. Together with the given speed and current commands, they constitute a complete sensorless control system, thereby achieving control of the motor operation.

[0067] The methods for obtaining speed and rotor position observations based on the position error signal include, but are not limited to, the following: a phase-locked loop (PLL) based tracking observation scheme, where the position error signal is used as the input to the PLL, and the PLL outputs the speed and rotor position observations; an estimation scheme based on a state observer, such as a sliding mode observer, a Luneburger observer, or an extended Kalman filter, where the position error signal is used as a correction quantity to estimate the state quantities in real time based on the motor's mathematical model; or an estimation scheme based on frequency tracking or adaptive filtering. The appropriate method can be selected based on actual engineering needs, and this embodiment does not impose any limitations.

[0068] The scheme using a phase-locked loop (PLL) is described below. The structure of the PLL can be found in [reference needed]. Figure 3 As shown, the position error signal As the input to the phase-locked loop, the proportional coefficient of the phase-locked loop is Kp, and the differential coefficient is Ki, which is used to input the position error signal. After proportional-integral adjustment, it goes through an integral stage. Obtain rotor position observations Rotor position observations After a differential step Obtain the observed rotational speed .

[0069] Among them, the motor includes, but is not limited to, a synchronous reluctance motor, a permanent magnet assisted synchronous reluctance motor, or a permanent magnet synchronous motor.

[0070] This embodiment converts the position error signal into speed and position observation values ​​that can be directly used for control, realizing a complete motor control closed loop without mechanical sensors. This reduces system cost and complexity, improves reliability in harsh environments, and, combined with the compensation for cross-saturation effect in the previous steps, enables the entire sensorless control system to maintain high-precision position observation and stable load-carrying capacity under zero-frequency, low-frequency, and load-changing conditions. This fundamentally solves the problem of performance degradation caused by inaccurate rotor position estimation.

[0071] Based on the above embodiments:

[0072] In one exemplary embodiment, the three-phase current signal is processed to obtain a high-frequency current signal corresponding to the high-frequency voltage injection component, including:

[0073] Convert the three-phase current signal into a stationary current signal in a two-phase stationary coordinate system;

[0074] The static current signal is transformed to the observation coordinate system to obtain the observation current signal in the observation coordinate system.

[0075] Extract the intermediate current signal generated by the high-frequency voltage injection component from the observed current signal;

[0076] High-frequency current signals are obtained based on intermediate current signals.

[0077] In this embodiment, the three-phase current signal is first converted using Clarke transform. Converted to a two-phase stationary coordinate system Two-phase static current signal under () The Clarke transform achieves an equivalent conversion from three-phase to two-phase, reducing the number of variables and simplifying subsequent processing, while preserving the amplitude and power relationships of the original system. This provides a more concise two-dimensional vector representation for subsequent signal separation in the rotating coordinate system. Then, based on the current rotor position observations, the static current signal (…) is transformed using the Park transform. Transform the signal to the observation coordinate system to obtain the observed current signal in the observation coordinate system. From the observed current signal, the intermediate current signal generated by the high-frequency voltage injection component is extracted. ).

[0078] Finally, the intermediate current signal ( After transformation by the rotation transformation matrix R, a high-frequency current signal is obtained. ), where the rotation transformation matrix .

[0079] This embodiment allows for more effective separation of the current component associated with high-frequency injection, further improving the accuracy of subsequent position error calculations.

[0080] In one exemplary embodiment, extracting an intermediate current signal generated by a high-frequency voltage injection component from an observed current signal includes:

[0081] The fundamental current component in the observed current signal is filtered out using a filter, while the current component corresponding to the high-frequency voltage injection component is retained as the intermediate current signal.

[0082] In this embodiment, the fundamental current component refers to the current component generated by the fundamental wave of the motor and with the same operating frequency as the motor. The purpose of this step is to directly remove the low-frequency operating current in the observation coordinate system, thereby extracting the signal generated by the high-frequency voltage injection component.

[0083] For example, observing current signals ( The frequency is included in The fundamental current component also includes frequencies of . The high-frequency voltage injection component (where A digital high-pass filter can be selected, and its cutoff frequency can be set to... and Between. After filtering, the fundamental current component is significantly attenuated, and the output signal The main included frequency is The components, namely the required intermediate current signal.

[0084] By filtering, it can be ensured that the current signal relied upon for subsequent processing mainly reflects the influence of high-frequency voltage injection components, minimizing the interference of motor load changes and fundamental current fluctuations on the position observation process and improving anti-interference capability.

[0085] In one exemplary embodiment, the motor control method further includes:

[0086] Obtain the d-axis inductance value, q-axis inductance value, and mutual inductance value between the d-axis and q-axis of the motor;

[0087] The cross-saturation correction coefficient is obtained based on the d-axis inductance value, the q-axis inductance value, and the mutual inductance value.

[0088] It can be understood that the cross-saturation correction coefficient in this embodiment is constructed as a function determined by the mutual inductance between the d-axis and q-axis of the motor, the d-axis inductance, and the q-axis inductance. This allows the interference terms introduced by the mutual inductance between the d and q axes, as represented in the mathematical model, to be canceled when the cross-saturation correction coefficient is used to calculate the high-frequency current component of a specific axis. This cancels the interference position information caused by magnetic circuit cross-coupling at the algorithm level.

[0089] In one exemplary embodiment, the high-frequency current signal includes a high-frequency current component of the injection axis and a high-frequency current component of the compensation axis. The injection axis is the axis into which the high-frequency voltage injection component is injected, and the compensation axis is an axis orthogonal to the injection axis.

[0090] The process of determining the position error signal based on the high-frequency current signal and the cross-saturation correction coefficient includes:

[0091] Based on the cross-saturation correction coefficient and the high-frequency current component of the injection axis, the cross-saturation interference compensation amount is obtained.

[0092] The position error signal is obtained based on the cross-saturation interference compensation amount and the high-frequency current component of the compensation axis.

[0093] In this embodiment, the high-frequency current signal is first decomposed into a high-frequency current component along the injection axis and a high-frequency current component along the compensation axis. The injection axis refers to the coordinate axis along which the actual injected high-frequency voltage component is located, while the compensation axis is a coordinate axis orthogonal to the injection axis. If the high-frequency voltage is injected onto the d-axis of the observation coordinate system, then the injection axis is the d-axis and the compensation axis is the q-axis; conversely, if the high-frequency voltage is injected onto the q-axis of the observation coordinate system, then the injection axis is the q-axis and the compensation axis is the d-axis. Then, based on the cross-saturation correction coefficient and the high-frequency current component along the injection axis, a cross-saturation interference compensation amount is calculated. Finally, based on this cross-saturation interference compensation amount and the high-frequency current component along the compensation axis, the final position error signal is obtained through calculation. The purpose of this axis-specific processing is to specifically counteract the interference introduced by the cross-saturation effect in a particular current component.

[0094] For example, assuming the high-frequency voltage is injected onto the d-axis of the observation coordinate system, the injection axis is the d-axis, the compensation axis is the q-axis, and the extracted high-frequency current component of the injection axis is... The high-frequency current component of the compensation axis is The cross-saturation correction factor is First, calculate the cross-saturation interference compensation amount as follows: Then, this compensation amount is compared with... By combining (e.g., subtracting), an intermediate error signal is obtained, from which the position error can be derived.

[0095] This structured calculation isolates the interference caused by cross-saturation from the position error signal, making the final position error more accurately reflect the actual position deviation of the rotor and improving the observation accuracy.

[0096] In one exemplary embodiment, a position error signal is obtained based on the cross-saturation interference compensation amount and the high-frequency current component of the compensation axis, including:

[0097] The high-frequency current component of the compensation axis is compensated based on the cross-saturation interference compensation amount to obtain the initial error signal;

[0098] The position error signal is obtained based on the initial error signal and the first preset coefficient;

[0099] The first preset coefficient is determined based on the high-frequency voltage injection component, the cross-saturation correction coefficient, and the inductance parameters of the motor. The inductance parameters include the inductance value of the injection shaft, the inductance value of the compensation shaft, and the mutual inductance value between the injection shaft and the compensation shaft.

[0100] In this embodiment, after obtaining the initial error signal after preliminary compensation, the final position error is calculated based on the initial error signal and a first preset coefficient. The first preset coefficient is determined jointly based on the characteristics of the high-frequency voltage injection component, the cross-saturation correction coefficient, and the motor's inductance parameters (including the inductance values ​​of the injection shaft, the compensation shaft, and the mutual inductance between the injection shaft and the compensation shaft). The purpose of introducing this coefficient is to adjust the error signal for subsequent phase-locked loop processing.

[0101] The voltage model of the rotating coordinate system of a synchronous reluctance motor can be understood as follows:

[0102] ;

[0103] in, It is the stator voltage. It is the stator current. It is the stator resistance. It is the synchronous operating frequency and the rotation transformation matrix. . It is the stator flux linkage, which satisfies Inductor matrix , These are d-axis and q-axis inductors. It is a permanent magnet flux linkage. It should be noted that this model is an ideal model and does not consider the cross saturation effect (i.e., mutual inductance). The superscript e indicates a synchronously rotating coordinate system.

[0104] To analyze the cross-saturation effect, the inductance matrix including mutual inductance needs to be considered. When injecting a high-frequency voltage component, the resistance voltage drop is ignored, and the injection frequency is much higher than the fundamental frequency. Therefore, the back EMF and voltage coupling terms related to the operating frequency in the voltage equation can be ignored, and the inductance cross-coupling term is considered, resulting in the simplified equation (dq coordinate system):

[0105] ;

[0106] in, It is the high-frequency voltage along the d-axis. It is the high-frequency voltage along the q-axis. It is the high-frequency current of the d-axis. It is the high-frequency current along the q-axis. It is the mutual inductance value between the d-axis and the q-axis.

[0107] The deformation yields (dq coordinate system):

[0108] ;

[0109] in, .

[0110] Assume the actual value of the true rotor position is The observed rotor position value is The observation error between the observed rotor position and the actual rotor position is The above equations are transformed from the physical coordinate system (dq axis system) to the observation coordinate system (dq axis system). (shaft system), which can be derived as follows:

[0111] ;

[0112] in, Under the observation coordinate system High-frequency voltage components of the shaft, Under the observation coordinate system High-frequency voltage components of the shaft, Under the observation coordinate system High-frequency current components of the shaft, Under the observation coordinate system High-frequency current components of the shaft, , .

[0113] High-frequency injection voltage Injected into the observation coordinate system; in this embodiment, the injection into the observation coordinate system... Axis, resulting in:

[0114] ;

[0115] Therefore, we get:

[0116] ;

[0117] The intermediate current signal under the observation coordinate system ( , After transformation by the rotation transformation matrix R, a high-frequency current signal is obtained. , This high-frequency current signal can be extracted using a high-pass filter or a band-pass filter.

[0118] exist , Under the assumptions, transforming the above equation, we can obtain:

[0119] ;

[0120] High-frequency current signal of the dq axis ( , The following position error equation is satisfied:

[0121] ;

[0122] Among them, the cross-saturation correction coefficient First preset coefficient .

[0123] Based on the position error equation described above, a phase-locked loop (PLL) is constructed to track the actual rotor position. When the position error signal is 0, the output angle of the PLL (the observed rotor position) is the actual rotor position angle.

[0124] This embodiment starts from the precise mathematical model of the synchronous reluctance motor and incorporates the inductance cross-saturation effect into the error signal generation stage of the high-frequency injection method through mathematical derivation. By introducing a cross-saturation correction coefficient directly calculated from the motor inductance parameters, the interference caused by the cross-saturation effect can be actively canceled at the signal processing level, thereby significantly improving the rotor position observation accuracy under conditions where the cross-saturation effect is significant, such as low frequency and heavy load. This embodiment does not rely on complex offline measurement or online identification tables, has a clear structure, and is easy to implement. It provides a more robust solution for high-performance sensorless control of synchronous reluctance motors, ensuring the steady-state and dynamic performance of the system across the entire operating range.

[0125] In one exemplary embodiment, the motor control method further includes:

[0126] Determine the reference cosine signal and the reference voltage amplitude;

[0127] Determine the sign and absolute value of the reference cosine signal;

[0128] A high-frequency voltage injection component is generated based on the larger of the absolute value and the preset minimum amplitude coefficient, the sign of the component, and the reference voltage amplitude.

[0129] In this embodiment, the high-frequency voltage injection component satisfy:

[0130] ;

[0131] in, The reference voltage amplitude, For injection frequency, For the preset minimum amplitude coefficient (e.g., 0.01), sgn() performs the sign operation, max() performs the maximum value operation, and abs() performs the absolute value operation.

[0132] This embodiment generates a high-frequency voltage injection component by processing a reference cosine signal. Compared with a square wave signal, this reduces high-frequency electromagnetic noise. Furthermore, by setting a minimum amplitude coefficient... Skipping the zero-crossing point of the cycle reduces the sensitivity of the phase-locked loop to noise signals.

[0133] In summary, please refer to Figure 4 , Figure 4 This application provides a block diagram of a high-frequency injection sensorless vector control for a synchronous reluctance motor. Figure 4 middle Given a rotational speed and an estimated rotational speed, These are the currents in phases A, B, and C. Given the d-axis and q-axis currents, To provide feedback on the d-axis and q-axis currents, PI (Proportional-Integral) is the regulator module, MTPA (Maximum Torque Per Ampere) is the maximum torque current module, allocating the given currents for the d-axis and q-axis, SVPWM (Space Vector Pulse Width Modulation) is the space vector modulation module, PLL (Phase-Locked Loop) is the phase-locked loop module, PMRM (Permanent Magnet Reluctance Motor) is the synchronous reluctance motor, and Signal Processing is the current signal processing module.

[0134] Specifically, given a rotational speed With the predicted speed The comparison generates a speed error, which is processed by a speed PI controller. The output of the speed PI controller is sent to the MTPA, and the MTPA outputs the q-axis current setpoint. and d-axis current setpoint ,Then, respectively with The errors of the two are compared, and the errors are passed through the d-axis PI controller and the q-axis PI controller, respectively. The output of the q-axis PI controller is used as the q-axis voltage command. The output of the d-axis PI controller is superimposed with a high-frequency voltage injection component. Later used as d-axis voltage command ,right and Perform the inverse Park transform and use the rotor position observations output by the phase-locked loop. Convert it into a two-phase stationary coordinate system ( ) target control voltage command ( , ), target control voltage command ( , The signal is fed into the space vector pulse width modulation (SVPWM) module, which generates six PWM pulse signals to drive the three-phase inverter. The inverter outputs three-phase voltages Ua, Ub, and Uc according to the PWM signals, which are applied to the stator windings of the synchronous reluctance motor (PMRM) to drive the motor to rotate.

[0135] The current sensor collects the three-phase current during motor operation. The three-phase current is converted into a current signal in a two-phase stationary coordinate system through Clarke transformation. , The current signal in the two-phase stationary coordinate system is transformed using Park transform and then processed using the PLL. Converted into a current signal in the dq coordinate system ( ),on the one hand Feedback is sent to the current regulator for closed-loop current control, on the other hand The signal is sent to the signal processing module, where the high-frequency current signal is extracted. , ), and then the high-frequency current signal ( , The data is fed into the PLL and output by the PLL. and The above controls shall be implemented.

[0136] Reference Figures 5-6 As shown, Figure 5 and Figure 6 The experimental results of the high-frequency injection sensorless vector control of the above synchronous reluctance motor are shown. The test condition is zero-frequency ride-through during motoring and generating, that is, the motor experiences forward motoring. Rated load - reverse generation Rated load - forward rotation electric The rated load changes. Comparing the speed and position information with those from the sensors, the speed and position observation results of the high-frequency injected sensorless vector control for the synchronous reluctance motor remain reliable and stable. This application fully considers the inherent characteristics of the synchronous reluctance motor and designs a high-frequency injected sensorless vector control scheme that can eliminate the influence of inductor cross-saturation. Based on the existing hardware of the frequency converter, no additional hardware circuits or encoders are required. By injecting high-frequency signals and constructing a phase-locked loop based on the extracted high-frequency current component information to track the actual rotor position information, the high-frequency injected open-loop vector zero-low-frequency control performance of the synchronous reluctance motor is greatly improved, exhibiting strong economic efficiency and engineering practicality.

[0137] Please refer to Figure 7 This application also provides a motor control device, including:

[0138] The first determining module 11 is used to determine the three-phase current signal of the motor under the target control voltage command; the target control voltage command includes a high-frequency voltage injection component.

[0139] Processing module 12 is used to process the three-phase current signal to obtain the high-frequency current signal corresponding to the high-frequency voltage injection component;

[0140] The second determining module 13 is used to determine the position error signal based on the high-frequency current signal and the cross-saturation correction coefficient; the cross-saturation correction coefficient is used to compensate for the interference component in the high-frequency current signal, and the interference component is obtained based on the cross-saturation effect between the d-axis inductance and the q-axis inductance of the motor.

[0141] The control module 14 is used to obtain the observed speed and rotor position values ​​based on the position error signal, and to control the motor based on the observed speed and rotor position values.

[0142] In one exemplary embodiment, the three-phase current signal is processed to obtain a high-frequency current signal corresponding to the high-frequency voltage injection component, including:

[0143] Convert the three-phase current signal into a stationary current signal in a two-phase stationary coordinate system;

[0144] The static current signal is transformed to the observation coordinate system to obtain the observation current signal in the observation coordinate system.

[0145] Extract the intermediate current signal generated by the high-frequency voltage injection component from the observed current signal;

[0146] High-frequency current signals are obtained based on intermediate current signals.

[0147] In one exemplary embodiment, extracting an intermediate current signal generated by a high-frequency voltage injection component from an observed current signal includes:

[0148] The fundamental current component in the observed current signal is filtered out using a filter, while the current component corresponding to the high-frequency voltage injection component is retained as the intermediate current signal.

[0149] In one exemplary embodiment, the motor control device further includes:

[0150] The first acquisition module is used to acquire the d-axis inductance value, q-axis inductance value, and mutual inductance value between the d-axis and q-axis of the motor.

[0151] The second acquisition module is used to obtain the cross saturation correction coefficient based on the d-axis inductance value, the q-axis inductance value, and the mutual inductance value.

[0152] In one exemplary embodiment, the high-frequency current signal includes a high-frequency current component of the injection axis and a high-frequency current component of the compensation axis. The injection axis is the axis into which the high-frequency voltage injection component is injected, and the compensation axis is an axis orthogonal to the injection axis.

[0153] The process of determining the position error signal based on the high-frequency current signal and the cross-saturation correction coefficient includes:

[0154] Based on the cross-saturation correction coefficient and the high-frequency current component of the injection axis, the cross-saturation interference compensation amount is obtained.

[0155] The position error signal is obtained based on the cross-saturation interference compensation amount and the high-frequency current component of the compensation axis.

[0156] In one exemplary embodiment, a position error signal is obtained based on the cross-saturation interference compensation amount and the high-frequency current component of the compensation axis, including:

[0157] The high-frequency current component of the compensation axis is compensated based on the cross-saturation interference compensation amount to obtain the initial error signal;

[0158] The position error signal is obtained based on the initial error signal and the first preset coefficient;

[0159] The first preset coefficient is determined based on the high-frequency voltage injection component, the cross-saturation correction coefficient, and the inductance parameters of the motor. The inductance parameters include the inductance value of the injection shaft, the inductance value of the compensation shaft, and the mutual inductance value between the injection shaft and the compensation shaft.

[0160] In one exemplary embodiment, the motor control device further includes:

[0161] The third determining module is used to determine the reference cosine signal and the reference voltage amplitude;

[0162] The fourth determination module is used to determine the sign and absolute value of the reference cosine signal;

[0163] The voltage generation module is used to generate a high-frequency voltage injection component based on the larger of the absolute value and the preset minimum amplitude coefficient, the sign, and the reference voltage amplitude.

[0164] This application also provides an electronic device, including:

[0165] Memory, used to store computer programs;

[0166] A processor is used to execute a computer program to implement the steps of the motor control method as described in any of the embodiments above.

[0167] Embodiments of this application also provide a computer-readable storage medium storing a computer program, wherein the computer program is configured to execute the steps in any of the above-described motor control method embodiments when it is run.

[0168] In one exemplary embodiment, the aforementioned computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard disk, magnetic disk, or optical disk.

[0169] Embodiments of this application also provide a computer program product, which includes a computer program that, when executed by a processor, implements the steps in any of the above-described motor control method embodiments.

[0170] Embodiments of this application also provide another computer program product, including a non-volatile computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps in any of the above-described motor control method embodiments.

[0171] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0172] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of controlling an electric machine, characterized by, The method comprises: determining a three-phase current signal of the motor under a target control voltage instruction; the target control voltage instruction comprises a high-frequency voltage injection component; processing the three-phase current signal to obtain a high-frequency current signal corresponding to the high-frequency voltage injection component; determining a position error signal based on the high-frequency current signal and a cross-saturation correction coefficient; the cross-saturation correction coefficient is used to compensate for an interference component in the high-frequency current signal, and the interference component is obtained based on a cross-saturation effect between a d-axis inductance and a q-axis inductance of the motor; obtaining a speed observation value and a rotor position observation value according to the position error signal, and controlling the motor based on the speed observation value and the rotor position observation value.

2. The motor control method according to claim 1, characterized by, The processing of the three-phase current signal to obtain a high-frequency current signal corresponding to the high-frequency voltage injection component comprises: converting the three-phase current signal into a stationary current signal in a two-phase stationary coordinate system; transforming the stationary current signal to an observation coordinate system to obtain an observation current signal in the observation coordinate system; extracting an intermediate current signal generated by the high-frequency voltage injection component from the observation current signal; obtaining the high-frequency current signal based on the intermediate current signal.

3. The motor control method according to claim 2, characterized by, The extraction of the intermediate current signal generated by the high-frequency voltage injection component from the observation current signal comprises: using a filter to filter out a fundamental current component in the observation current signal and retain a current component corresponding to the high-frequency voltage injection component as an intermediate current signal.

4. The motor control method of claim 1, wherein The motor control method further comprises: obtaining a d-axis inductance value, a q-axis inductance value, and a mutual inductance value between the d-axis and the q-axis of the motor; obtaining the cross-saturation correction coefficient based on the d-axis inductance value, the q-axis inductance value, and the mutual inductance value.

5. The motor control method of claim 1, wherein The high-frequency current signal comprises a high-frequency current component of an injection axis and a high-frequency current component of a compensation axis, the injection axis being an axis on which the high-frequency voltage injection component is injected, and the compensation axis being an axis orthogonal to the injection axis; The process of determining a position error signal based on the high-frequency current signal and a cross-saturation correction coefficient comprises: obtaining a cross-saturation interference compensation amount based on the cross-saturation correction coefficient and the high-frequency current component of the injection axis; obtaining the position error signal based on the cross-saturation interference compensation amount and the high-frequency current component of the compensation axis.

6. The motor control method according to claim 5, characterized by, Obtaining the position error signal based on the cross-saturation interference compensation amount and the high-frequency current component of the compensation axis comprises: compensating for the high-frequency current component of the compensation axis based on the cross-saturation interference compensation amount to obtain an initial error signal; obtaining the position error signal based on the initial error signal and a first preset coefficient; wherein the first preset coefficient is determined based on the high-frequency voltage injection component, the cross-saturation correction coefficient, and inductance parameters of the motor, the inductance parameters comprising an inductance value of the injection axis, an inductance value of the compensation axis, and a mutual inductance value between the injection axis and the compensation axis.

7. The motor control method according to any one of claims 1 to 6, characterized by, The motor control method further comprises: determining a reference cosine signal and a reference voltage amplitude; determining a sign and an absolute value of the reference cosine signal; The high-frequency voltage injection component is generated according to a larger value between the absolute value and a preset minimum amplitude coefficient, the symbol, and the reference voltage amplitude.

8. An electric motor control device characterized by comprising: The method comprises the steps of: A first determining module is configured to determine a three-phase current signal of the motor under a target control voltage instruction; the target control voltage instruction comprises a high-frequency voltage injection component; A processing module is configured to process the three-phase current signal to obtain a high-frequency current signal corresponding to the high-frequency voltage injection component; A second determining module is configured to determine a position error signal based on the high-frequency current signal and a cross-saturation correction coefficient; the cross-saturation correction coefficient is used to compensate for an interference component in the high-frequency current signal, and the interference component is obtained based on a cross-saturation effect between a d-axis inductance and a q-axis inductance of the motor; A control module is configured to obtain a speed observation value and a rotor position observation value according to the position error signal, and control the motor based on the speed observation value and the rotor position observation value.

9. An electronic device, comprising: The method comprises the steps of: A memory is configured to store a computer program; A processor is configured to implement the steps of the motor control method according to any one of claims 1-7 when executing the computer program.

10. A computer-readable storage medium, characterized in that, A computer program is stored on the computer readable storage medium, and the computer program is executed by the processor to implement the steps of the motor control method according to any one of claims 1-7.

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