Motor control method and device, equipment and storage medium

Abstract

The invention provides 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: obtaining an expected control current and an actual control current of a motor; using a current tracking module to generate a control voltage according to a current difference between the expected control current and the actual control current; a disturbance suppression module is used for generating disturbance compensation voltage according to the actual control current and the internal model principle; generating a target voltage according to the control voltage and the disturbance compensation voltage by using a harmonic suppression module; and controlling the motor to operate based on the target voltage. The method is suitable for a motor control process and is used for solving the problem of torque fluctuation caused by interference of current harmonics.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automobiles, in particular to the field of motor control, and specifically to a motor control method, device, equipment and storage medium. BACKGROUND

[0002] Automobile manufacturers mainly use permanent magnet synchronous motors as the power structure of the electric drive system, and the torque accuracy of the permanent magnet synchronous motor is an important indicator for measuring the performance of the electric drive system, which directly affects the driving performance and noise vibration harshness (NVH) of new energy electric vehicles.

[0003] Current harmonics are an important cause of torque accuracy, which not only causes torque fluctuation and vibration noise, but also causes motor heating and reduces power conversion efficiency.

[0004] Torque fluctuation suppression has always been a research hotspot in the field of motor control. In related technologies, torque fluctuation suppression can be achieved by optimizing the structure of the motor. Engineering and technical personnel can use torque fluctuation as a design indicator when designing the motor, and optimize the key dimensions of the motor through various optimization algorithms to minimize torque fluctuation.

[0005] However, after the motor is designed, the inverter will also introduce current harmonic interference. Although the method of optimizing the structure of the motor can improve torque performance, it can only solve the torque fluctuation caused by the motor itself, and cannot solve the torque fluctuation caused by the current harmonic interference introduced by the inverter. SUMMARY

[0006] Based on the above technical problems, the present application provides a motor control method, device, equipment and storage medium, which can control the torque fluctuation caused by current harmonics using software algorithms.

[0007] In a first aspect, the present application provides a motor control method, which comprises: obtaining a desired control current and an actual control current of a motor; determining a target voltage by a processing module according to the desired control current and the actual control current;

[0008] The processing module comprises: a current tracking module, a disturbance suppression module and a harmonic suppression module; the current tracking module is configured to generate a control voltage according to the current difference between the desired control current and the actual control current; the disturbance suppression module is configured to generate a disturbance compensation voltage according to the actual control current and the internal model principle; the harmonic suppression module is configured to generate the target voltage according to the control voltage and the disturbance compensation voltage; and the motor is controlled to operate based on the target voltage.

[0009] Optionally, the transfer function of the current tracking module satisfies the following formula:

[0010]

[0011] wherein GA(s) represents a transfer function of the current tracking module; D ry (s) represents a transfer function describing a tracking trajectory of the current loop, D ry (s) = 1 / (ps + 1), p represents a dynamic response coefficient; s represents a Laplace operator; Q m (s) represents an updated transfer function of the disturbance rejection module; P n (s) represents a mathematical model of the motor;

[0012]

[0013] wherein R(s) represents a control function of the harmonic rejection module; Q(s) represents an original transfer function of the disturbance rejection module;

[0014]

[0015] wherein k f represents a gain coefficient; s represents a Laplace operator; a represents an order; w h represents a resonance frequency of the harmonic rejection module; w c represents a cut-off frequency of the harmonic rejection module;

[0016]

[0017] wherein t represents a preset parameter determining bandwidths of the current tracking module and the disturbance rejection module.

[0018] Optionally, the transfer function of the disturbance rejection module satisfies the following formula:

[0019]

[0020] wherein GB(s) represents a transfer function of the disturbance rejection module; Q(s) represents an original transfer function of the disturbance rejection module; P n (s) represents a mathematical model of the motor; Q m (s) represents an updated transfer function of the disturbance rejection module;

[0021]

[0022] wherein R(s) represents a control function of the harmonic rejection module;

[0023]

[0024] wherein k f represents a gain coefficient; s represents a Laplace operator; a represents an order; w h represents a resonance frequency of the harmonic rejection module; wc This indicates the cutoff frequency of the harmonic suppression module;

[0025]

[0026] Where τ represents the preset parameter that determines the bandwidth of the current tracking module and the disturbance suppression module.

[0027] Optionally, the transfer function of the harmonic suppression module satisfies the following formula:

[0028]

[0029] Where GR(s) represents the transfer function after the harmonic suppression module is embedded in the controlled object; k f ω represents the gain coefficient; s represents the Laplace operator; α represents the order; ω h ω represents the resonant frequency of the harmonic suppression module. c Indicates the cutoff frequency of the harmonic suppression module; L q This represents the q-axis inductance of the motor.

[0030] Optionally, for the q-axis of the motor, a target voltage is generated using a harmonic suppression module based on the control voltage and disturbance compensation voltage, including:

[0031] The target voltage is generated according to the following formula:

[0032]

[0033] U2(t)=[1+Q(s)+GR(s)]U1(t);

[0034] Where U2(t) represents the target voltage; U1(t) represents the difference between the control voltage and the disturbance compensation voltage; Indicates the control voltage; Indicates the disturbance compensation voltage; k A0 =L q / ρ;e c (t) represents the current difference between the desired control current and the actual control current, e c (t)=i q (t)-O(t), i q O(t) represents the desired control current of the q-axis of the motor, and O(t) represents the actual control current of the q-axis of the motor; k A1 =(2L) q +Rτ) / ρτ;k A2 =(L q +2τR) / (ρτ) 2 ;k A3 =R / (ρτ) 2 ;kB0 =2L q / τ;k B1 =(L q +2τR) / τ 2 ;k B2 =R / τ 2 L q ρ represents the q-axis inductance of the motor; R represents the stator resistance of the motor; ρ represents the dynamic response coefficient; τ represents the preset parameter that determines the bandwidth of the current tracking module and the disturbance suppression module; t, l, and h represent different integration times; Q(s) represents the original transfer function of the disturbance suppression module; GR(s) represents the transfer function of the harmonic suppression module after it is embedded in the controlled object.

[0035] Optionally, the harmonic suppression module satisfies the following formula:

[0036]

[0037] Where, U(s) k U(s) represents the target voltage output by the harmonic suppression module at time k. k-1 E(s) represents the target voltage output by the harmonic suppression module at time k-1. k This represents the control voltage and disturbance compensation voltage input to the harmonic suppression module at time k; ω h ω represents the resonant frequency of the harmonic suppression module. c The cutoff frequency of the harmonic suppression module is represented by s; s represents the Laplace operator; α represents the order; k f L represents the gain coefficient; q R represents the q-axis inductance of the motor; R represents the stator resistance of the motor.

[0038] Optionally, controlling motor operation based on the target voltage includes: performing an inverse Park transformation on the target voltage to obtain a three-phase AC signal; performing space vector pulse width modulation on the three-phase AC signal to obtain a pulse width modulation waveform; and controlling the switching state of the three-phase inverter through the pulse width modulation waveform to generate a corresponding duty cycle to control the motor.

[0039] Secondly, this application provides a motor control device that includes various functional units for the method described in the first aspect above.

[0040] Thirdly, this application provides an electronic device comprising: a processor and a memory; the memory storing processor-executable instructions; when the processor is configured to execute the instructions, the electronic device performs the method described in the first aspect above.

[0041] Fourthly, this application provides a readable storage medium comprising: software instructions; when the software instructions are executed in an electronic device, they cause the electronic device to perform the method described in the first aspect above.

[0042] Fifthly, this application provides a computer program product that, when run in an electronic device, causes the electronic device to perform the method described in the first aspect above.

[0043] Therefore, the above-mentioned technical features of this application have the following beneficial effects:

[0044] (1) The motor control method provided in this application can obtain the desired control current and the actual control current of the motor; generate a control voltage based on the current difference between the desired control current and the actual control current using a current tracking module; generate a disturbance compensation voltage based on the actual control current and the internal model principle using a disturbance suppression module; generate a target voltage based on the control voltage and the disturbance compensation voltage using a harmonic suppression module; and control the motor operation based on the target voltage. No optimization of the motor structure is required; torque fluctuations caused by current harmonics can be controlled through a software algorithm module.

[0045] (2) This application redesigns the disturbance suppression module based on the improved harmonic suppression module, and constructs a three-degree-of-freedom robust control algorithm based on harmonic suppression based on the disturbance suppression module. Compared with the traditional PI, the three-degree-of-freedom control algorithm is adopted, which has better harmonic suppression effect and can achieve high-performance current control.

[0046] (3) The motor control method provided in this application is based on fractional-order operators and complex vector filters. The resonant controller (i.e., harmonic suppression module) is redesigned, which improves the bandwidth of the resonant controller at the harmonic frequency. It can ensure that the resonant controller can still maintain a large gain when the harmonic frequency fluctuates, and ensure that the harmonic suppression signal has low amplitude attenuation and small phase deviation.

[0047] (4) This application can also embed the controlled object in the harmonic suppression module, which can further eliminate the frequency domain attenuation caused by the controlled object, thereby suppressing harmonics more effectively.

[0048] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0049] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application, and do not constitute an undue limitation of this application.

[0050] Figure 1A schematic flowchart illustrating the motor control method provided in an embodiment of this application;

[0051] Figure 2 A control block diagram of the improved resonance control algorithm provided in the embodiments of this application;

[0052] Figure 3 Bode plot of the improved resonance control algorithm provided in the embodiments of this application;

[0053] Figure 4 Another schematic flowchart of the motor control method provided in the embodiments of this application;

[0054] Figure 5 A control block diagram of a permanent magnet synchronous motor using a three-degree-of-freedom robust control algorithm is provided for embodiments of this application;

[0055] Figure 6 This is a control block diagram of a three-degree-of-freedom robust control algorithm provided in an embodiment of this application;

[0056] Figure 7 This is a comparative diagram of frequency response characteristics provided in the embodiments of this application;

[0057] Figure 8 The current loop dynamic response diagram provided in the embodiments of this application;

[0058] Figure 9 The current waveform curve provided for the embodiments of this application;

[0059] Figure 10 This is a schematic diagram of the composition of the motor control device provided in the embodiments of this application;

[0060] Figure 11 This is a schematic diagram illustrating the composition of an electronic device provided in an embodiment of this application. Detailed Implementation

[0061] To enable those skilled in the art to better understand the technical solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0062] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0063] Sales of new energy electric vehicles are increasing day by day, showing broad market prospects. As one of the core technologies of new energy electric vehicles, the electric drive system directly affects driving comfort and safety.

[0064] Considering the efficiency of power conversion, automakers mainly use permanent magnet synchronous motors as the power structure of electric drive systems. The torque accuracy of permanent magnet synchronous motors is an important indicator for measuring the performance of electric drive systems, which directly affects the driving performance and vibration and noise levels (NVH) of new energy electric vehicles.

[0065] According to the national standard GB / T 18488.1-2015-Motors and controllers for electric vehicles Part 1-Technical conditions, the torque accuracy of the motor must be ensured as follows: below 100Nm, the torque accuracy is controlled within ±5Nm; above 100Nm, the torque accuracy is within ±5%.

[0066] Current harmonics are a significant factor affecting torque accuracy. They not only cause torque fluctuations and vibration noise, but also cause motor heating and reduce energy conversion efficiency.

[0067] Torque ripple suppression has always been a research hotspot in the field of motor control. Related technologies can achieve torque ripple suppression by optimizing the motor's structure. When designing motors, engineers can use torque ripple as a design indicator and optimize the motor's critical dimensions using various optimization algorithms to minimize torque ripple.

[0068] However, once the motor design is complete, the inverter will also introduce interference from current harmonics. Although optimizing the motor structure can improve torque performance, it can only solve the torque fluctuations generated by the motor itself, and cannot solve the torque fluctuations caused by the interference from current harmonics introduced by the inverter.

[0069] Based on this, embodiments of this application provide a motor control method, apparatus, device, and storage medium that can use software algorithms to control torque fluctuations caused by current harmonics.

[0070] The execution entity of the motor control method provided in this application embodiment is a motor control device, which may be a controller; or, the motor control device may be an application (APP) in the aforementioned controller; or, the motor control device may be a processor (e.g., a central processing unit (CPU)) in the aforementioned controller; or, the motor control device may be a functional module or functional unit in the aforementioned controller for executing the motor control method; or, the motor control device may be other devices connected to the aforementioned controller, etc. This application embodiment does not impose any limitations on these aspects.

[0071] For simplicity, the following description will use a motor control device as the main actuator.

[0072] Figure 1 This is a flowchart illustrating the motor control method provided in an embodiment of this application. Figure 1 As shown, the method includes the following steps:

[0073] S101, The motor control device obtains the desired control current and the actual control current of the motor.

[0074] The desired control current can be determined by the motor control device or other controllers based on the motor's application environment and operating requirements, such as the vehicle's operating conditions or load. The actual control current can be detected by a current detection device (e.g., an ammeter) installed in the motor system.

[0075] S102. The motor control device uses a current tracking module to generate a control voltage based on the current difference between the desired control current and the actual control current.

[0076] The current tracking module is used to generate a control voltage based on the current difference between the desired control current and the actual control current.

[0077] S103. The motor control device uses the disturbance suppression module to generate a disturbance compensation voltage based on the actual control current and the internal model principle.

[0078] The disturbance suppression module is used to generate disturbance compensation voltage based on the actual control current and the internal model principle.

[0079] S104. The motor control device uses the harmonic suppression module to generate the target voltage based on the control voltage and the disturbance compensation voltage.

[0080] The harmonic suppression module is used to generate the target voltage based on the control voltage and the disturbance compensation voltage.

[0081] The specific implementation of the current tracking module, disturbance suppression module, and harmonic suppression module can be referred to in the following embodiments, and will not be repeated here.

[0082] S105, The motor control device controls the motor operation based on the target voltage.

[0083] The specific process of S105 can be referred to in the following embodiments, and will not be repeated here.

[0084] The motor control method provided in this application can obtain the desired control current and the actual control current of the motor; generate a control voltage based on the current difference between the desired and actual control currents using a current tracking module; generate a disturbance compensation voltage based on the actual control current and the internal model principle using a disturbance suppression module; generate a target voltage based on the control voltage and the disturbance compensation voltage using a harmonic suppression module; and control the motor operation based on the target voltage. No structural optimization of the motor is required; torque fluctuations caused by current harmonics can be controlled through a software algorithm module.

[0085] Furthermore, this application constructs a three-degree-of-freedom robust control algorithm based on harmonic suppression; compared with the traditional PI, the three-degree-of-freedom control algorithm has better harmonic suppression effect and can achieve high-performance current control.

[0086] The following describes the current tracking module, disturbance suppression module, and harmonic suppression module in S102 to S104 above.

[0087] First, the derivation process for the harmonic suppression module can include the following steps:

[0088] Step 1: Determine the complex vector filter and fractional-order operator as follows:

[0089]

[0090] In formulas (1) and (2), G(s) + ,G(s) - This represents a vector filter that suppresses positive and negative order harmonic signals, respectively; ω h ω c The resonant and cutoff frequencies of the filter are represented by F(s) and T(s), respectively; these represent the fractional-order operators. f α represents the gain coefficient. s represents the Laplace operator. α represents the order.

[0091] Step 2: Substitute formula (2) into formula (1) and sum them up to get:

[0092]

[0093] In formula (3), R(s) represents the control function of the harmonic suppression module.

[0094] Combining formula (2), it can be seen that although the harmonic suppression module based on the complex vector filter can suppress positive and negative sequence harmonics, it is limited at harmonic frequencies jω. h The existence of infinite gain not only leads to instability in the control algorithm but also causes infinite word length, thus necessitating further modifications to the algorithm.

[0095] Step 3: For fractional operators (jω) h α can be further expanded to obtain:

[0096]

[0097] Step 4: To obtain a larger bandwidth for the resonant control algorithm, the operator is approximated as follows:

[0098]

[0099] Where, ω c This is the cutoff frequency, measured in rad / s, used to prevent the harmonic suppression module from generating infinite gain.

[0100] Step 5: Substitute formula (5) back into formulas (2) and (1) to obtain the improved harmonic suppression module (or resonance control algorithm) as follows:

[0101]

[0102] Step 6: If the frequency of the resonant signal is much greater than the damping coefficient, the following inequality can be obtained:

[0103]

[0104] Step 7, At this time, It can be regarded as a higher-order infinitesimal and neglected. Formula (6) can be further rewritten as:

[0105]

[0106] Step 8: Establish the voltage equations for the permanent magnet synchronous motor as follows:

[0107]

[0108] Among them, V d V q i d i q L represents the stator voltage and current along the d and q axes in a synchronous rotating coordinate system, respectively. d L q R s ω e =Pω m, λ f The values ​​represent the d-axis inductance, resistance, synchronous speed, and permanent magnet flux linkage, respectively; P is the number of pole pairs of the motor.

[0109] Step 9: From formula (9), it can be seen that there is coupling between the d-axis and q-axis voltages. The coupling voltage not only affects the tracking performance of the current loop, but also reduces the stability of the control loop. To eliminate the influence of the coupling term, a feedforward decoupling method is adopted. The feedforward voltage is designed as follows:

[0110]

[0111] Step 10: The voltage equation using feedforward decoupling can be further simplified to:

[0112]

[0113] Step 11: Based on the Laplace transform, the transfer functions of voltage and current can be obtained as follows:

[0114]

[0115] In formula (12), P d (s) represents the transfer function of voltage and current along the d-axis. P q (s) represents the transfer function of voltage and current along the q-axis.

[0116] Step 12: As can be seen from formula (12), the controlled object is a first-order inertial element. In the control loop, it will cause control gain attenuation and phase shift, affecting control performance. Therefore, the inverse of the controlled object is embedded in the improved harmonic suppression module (or resonant control algorithm) to achieve zero-pole cancellation, improve control gain and reduce phase delay. The harmonic suppression module (or resonant control algorithm) with the inverse of the controlled object embedded is as follows:

[0117]

[0118] Where GR(s) represents the transfer function after the harmonic suppression module is embedded in the controlled object.

[0119] The motor control method provided in this application redesigns the resonant controller (i.e., the harmonic suppression module) based on fractional-order operators and complex vector filters, thereby increasing the bandwidth of the resonant controller at harmonic frequencies. This ensures that the resonant controller can maintain a large gain even when the harmonic frequency fluctuates, and guarantees low amplitude attenuation and small phase deviation of the harmonic suppression signal.

[0120] Furthermore, this application can also embed a controlled object in the harmonic suppression module, which can further eliminate the frequency domain attenuation caused by the controlled object, thereby suppressing harmonics more effectively.

[0121] Step 13: Based on formula (13), the digital implementation of the improved harmonic suppression module (or resonance control algorithm) can be obtained, as shown below:

[0122]

[0123] Where, U(s) k E(s) k U(s) represents the voltage output (i.e., target voltage) of the harmonic suppression module and the input signal (i.e., the control voltage generated by the current tracking module and the disturbance compensation voltage generated by the disturbance suppression module) at time k; k1 This represents the voltage output at the previous moment.

[0124] For example, Figure 2 A control block diagram of the improved resonance control algorithm provided in the embodiments of this application. Figure 2 As shown, when a harmonic signal with the same center frequency as the harmonic suppression module enters the harmonic suppression module, the harmonic suppression module will generate a compensation signal with the same amplitude and frequency as the harmonic signal but with a phase difference of 180°. The compensation signal is superimposed on the harmonic signal in the system, thereby eliminating the influence of harmonics on the control loop.

[0125] For example, Figure 3 Bode plot of the improved resonance control algorithm provided in the embodiments of this application. Figure 3 As shown, the bandwidth of the harmonic suppression module in the fractional-order case (α = 0.85, 0.65) is significantly greater than that of the traditional integer-order resonant controller (α = 1). This indicates that the improved resonant control algorithm can have stronger robustness to changes in harmonic signals. Furthermore, reducing the controller order α can increase the controller gain, thereby achieving more effective harmonic suppression.

[0126] Then, the derivation process for the current tracking module and the disturbance suppression module can include the following steps:

[0127] Step 1: From formula (12), it can be seen that the mathematical models of d-axis and q-axis voltages are exactly the same. Taking q-axis current as an example, in order to achieve good tracking performance and good robustness, the current tracking module and the disturbance suppression module form a two-degree-of-freedom control architecture to realize the tracking and disturbance suppression of the current loop. Its design is as follows:

[0128]

[0129] Where GA(s) represents the transfer function of the current tracking module. Dry(s) = 1 / (ρs+1) represents the transfer function describing the current loop tracking trajectory; ρ is the dynamic response coefficient, the smaller ρ is, the faster the dynamic response, and this parameter has a lower limit ρ due to the influence of the controller bandwidth. min P n(s)=1 / (L q s+R s ) represents the mathematical model of the controlled object (i.e., the motor). GB(s) represents the transfer function of the disturbance suppression module.

[0130] Step 2, Q(s) represents the original transfer function of the disturbance suppression module, which can be expressed as:

[0131]

[0132] Wherein, τ represents a preset parameter that determines the bandwidth of the current tracking module and the disturbance suppression module. The smaller τ is, the better the system robustness. However, due to the influence of noise, this parameter cannot be infinitely small and has a lower limit value τ. min .

[0133] Step 3: To suppress current harmonics, the harmonic suppression module is equivalent to a bandpass filter. Based on the internal model principle, the harmonic suppression module is embedded in the disturbance suppression module to improve the bandwidth and control gain of the control loop at the harmonic frequency, thereby achieving good harmonic suppression. This patent provides an embedded design method to redesign the disturbance suppression module, whose transfer function is shown below:

[0134]

[0135] Step 4: Substitute formula (15) back into formula (13) to obtain the current loop controller as follows:

[0136]

[0137] The redesigned current loop controller comprises three parts: a current tracking module, a disturbance suppression module, and a harmonic suppression module, which respectively realize command tracking, disturbance suppression, and harmonic suppression of the current loop. Adjusting parameter ρ alone can achieve fast current loop tracking within a limited bandwidth, while adjusting parameter τ can achieve good disturbance suppression by the controller. The improved harmonic suppression module is embedded serially at the front end of the controller, which can achieve good suppression of harmonics. The three parts are independent of each other, so this invention can be understood as a three-degree-of-freedom robust control algorithm.

[0138] The input to the entire current loop controller is the current error e between the desired control current and the actual control current. c (t), e c (t)=i q (t)-O(t), i q O(t) represents the desired control current of the q-axis of the motor, and O(t) represents the actual control current of the q-axis of the motor. Taking this as an example, the current error can be obtained by equation (18). The initial voltage of the current loop tracking module and the disturbance compensation module can be expressed as follows:

[0139]

[0140] In formula (19), U1(t) represents the initial voltage, which is the difference between the control voltage and the disturbance compensation voltage; Indicates the control voltage; Indicates the disturbance compensation voltage; k A0 =L q / ρ;k A1 =(2L) q +Rτ) / ρτ;k A2 =(L q +2τR) / (ρτ) 2 ;k A3 =R / (ρτ) 2 ;k B0 =2L q / τ;k B1 =(L q +2τR) / τ 2 ;k B2 =R / τ 2 L q R represents the q-axis inductance of the motor; R represents the stator resistance of the motor; ρ represents the dynamic response coefficient; τ represents the preset parameter that determines the bandwidth of the current tracking module and the disturbance suppression module; t, l, and h represent different integration times.

[0141] To further achieve effective suppression of current harmonics, the initial voltage can be processed by a harmonic suppression module to obtain the final target voltage, as shown below:

[0142] U2(t)=[1+Q(s)+GR(s)]U1(t) Formula (20)

[0143] In formula (20), U2(t) represents the target voltage.

[0144] The specific process of S103 described above is described below.

[0145] In some possible embodiments, Figure 4 This is another schematic flowchart illustrating the motor control method provided in an embodiment of this application. Figure 4 As shown, the above S105 may specifically include S1051 to S1053.

[0146] S1051 The motor control device performs an inverse Park transformation on the target voltage to obtain a three-phase AC signal.

[0147] The Park transform is a method for converting a three-phase AC signal (usually in the abc coordinate system) into a two-phase rotating coordinate system (dq coordinate system). Correspondingly, the inverse Park transform refers to converting a signal in the dq coordinate system back into the abc coordinate system. The inverse Park transform is mainly used to convert voltage or current signals obtained in the dq coordinate system after the Park transform back into three-phase AC signals.

[0148] S1052. The motor control device performs space vector pulse width modulation based on the three-phase AC signal to obtain the pulse width modulation waveform.

[0149] The specific process of space vector pulse width modulation (SVPWM) can be found in the relevant technical descriptions, and will not be repeated here.

[0150] S1053 The motor control device controls the switching state of the three-phase inverter through pulse width modulation waveform to generate the corresponding duty cycle to control the motor.

[0151] The specific process of S1053 can be found in the relevant technical documents, and will not be repeated here.

[0152] For example, Figure 5 This is a control block diagram of a permanent magnet synchronous motor using a three-degree-of-freedom robust control algorithm, provided as an embodiment of this application. Figure 5 As shown, the current sensor collects the three-phase current, i a i b i c The current i in the two-phase rotating coordinate system is obtained after coordinate transformation. d i q The difference between the given current and the feedback current is used to generate the control voltage in the current tracking module. The feedback current enters the harmonic suppression module to generate the disturbance compensation voltage. The two are superimposed and then processed by the harmonic suppression module to generate the final target voltage. The target voltage passes through the inverter to generate the corresponding duty cycle to control the motor and complete the torque output.

[0153] Based on the understanding of the above embodiments, Figure 6 This is a control block diagram of a three-degree-of-freedom robust control algorithm provided in an embodiment of this application. Figure 6As shown, the three-degree-of-freedom robust control algorithm consists of three modules: a current tracking module, a disturbance suppression module, and a harmonic suppression module. The current tracking module generates a corresponding control voltage based on the current error to eliminate the error between the command current and the actual current. The disturbance suppression module generates a disturbance compensation voltage based on the feedback current, thereby improving the current loop's ability to suppress disturbances. The harmonic suppression module further processes the voltage commands generated by the current tracking and disturbance suppression modules, and effectively suppresses harmonic signals by maintaining unity gain of the control loop at harmonic frequencies.

[0154] For example, Figure 7 This is a comparative diagram of frequency response characteristics provided in an embodiment of this application. Figure 7 As shown, R(s)+Q(s) represents the frequency response characteristics of the harmonic suppression module and the disturbance suppression module before the improved transfer function. m (s) represents the frequency response characteristics of the harmonic suppression module and the disturbance suppression module after the improved transfer function. After introducing the improved current loop controller, the low-frequency disturbance suppression region expands from 0.979 rad / s to 1.89 rad / s, indicating that the control algorithm enhances the suppression of low-frequency disturbances. Furthermore, at the harmonic frequency (i.e.,...)... Figure 7 At the harmonic disturbance suppression region (in the model), a 45dB attenuation was observed, indicating that the robust three-degree-of-freedom control algorithm can effectively suppress harmonic signals.

[0155] For example, Figure 8 The current loop dynamic response diagram provided in the embodiments of this application is shown. Figure 8 As shown, using the traditional PI control algorithm, the current loop step response exhibits an overshoot of 20% and a settling time of 0.32s; using the three-degree-of-freedom robust control algorithm based on harmonic suppression proposed in this application, the overshoot is reduced to 1.9% and the settling time is reduced to 0.03s.

[0156] For example, Figure 9 The current waveform curve provided for an embodiment of this application. Figure 9 As shown in (a), taking a desired control current of 0A on the d-axis and 5A on the q-axis as an example, the phase current harmonic distortion rate (or the distortion rate between the desired control current and the actual control current) under PI control is 1.36%. Figure 9 As shown in (b) of this application, the harmonic distortion rate can be further reduced to 0.25% using the algorithm proposed in the embodiments of this application, and the current harmonics are significantly suppressed.

[0157] The foregoing mainly describes the solutions provided by the embodiments of this application from a methodological perspective. To achieve the above functions, the control device includes hardware structures and / or software units corresponding to the execution of each function. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0158] This application embodiment can, according to the above method, exemplarily divide the control device into functional units. For example, the control device may include functional units corresponding to each functional division, or two or more functions may be integrated into one processing unit. The integrated unit can be implemented in hardware or as a software functional unit. It should be noted that the unit division in this application embodiment is illustrative and only represents one logical functional division; in actual implementation, there may be other division methods.

[0159] In an exemplary embodiment, this application provides a motor control device. Figure 10 This is a schematic diagram illustrating the composition of the motor control device provided in an embodiment of this application. Figure 10 As shown, the device includes an acquisition unit 1001 and a processing unit 1002.

[0160] The acquisition unit 1001 is used to acquire the desired control current and the actual control current of the motor;

[0161] The processing unit 1002 is used to generate a control voltage based on the current difference between the desired control current and the actual control current using a current tracking module; generate a disturbance compensation voltage based on the actual control current and the internal model principle using a disturbance suppression module; generate a target voltage based on the control voltage and the disturbance compensation voltage using a harmonic suppression module; and control the motor to operate based on the target voltage.

[0162] In some possible embodiments, the transfer function of the current tracking module satisfies the following formula:

[0163]

[0164] Where GA(s) represents the transfer function of the current tracking module; D ry (s) represents the transfer function describing the current loop tracking trajectory, D ry(s) = 1 / (ρs+1), where ρ represents the dynamic response coefficient; s represents the Laplace operator; Q m (s) represents the update transfer function of the disturbance suppression module; P n (s) represents the mathematical model of the motor;

[0165]

[0166] Where R(s) represents the control function of the harmonic suppression module; Q(s) represents the original transfer function of the disturbance suppression module;

[0167]

[0168] Where, k f ω represents the gain coefficient; s represents the Laplace operator; α represents the order; ω h ω represents the resonant frequency of the harmonic suppression module. c This indicates the cutoff frequency of the harmonic suppression module;

[0169]

[0170] Where τ represents the preset parameter that determines the bandwidth of the current tracking module and the disturbance suppression module.

[0171] In other possible embodiments, the transfer function of the disturbance suppression module satisfies the following formula:

[0172]

[0173] Where GB(s) represents the transfer function of the disturbance suppression module; Q(s) represents the original transfer function of the disturbance suppression module; P n (s) represents the mathematical model of the motor; Q m (s) represents the update transfer function of the disturbance suppression module;

[0174]

[0175] Where R(s) represents the control function of the harmonic suppression module;

[0176]

[0177] Where, k f ω represents the gain coefficient; s represents the Laplace operator; α represents the order; ω h ω represents the resonant frequency of the harmonic suppression module. c This indicates the cutoff frequency of the harmonic suppression module;

[0178]

[0179] Where τ represents the preset parameter that determines the bandwidth of the current tracking module and the disturbance suppression module.

[0180] In some other possible embodiments, the transfer function of the harmonic suppression module satisfies the following formula:

[0181]

[0182] Where GR(s) represents the transfer function after the harmonic suppression module is embedded in the controlled object; k f ω represents the gain coefficient; s represents the Laplace operator; α represents the order; ω h ω represents the resonant frequency of the harmonic suppression module. c Indicates the cutoff frequency of the harmonic suppression module; L q This represents the q-axis inductance of the motor.

[0183] In some other possible embodiments, the processing unit 1002 is specifically configured to generate the target voltage according to the following formula:

[0184] U2(t)=[1+Q(s)+GR(s)]U1(t);

[0185]

[0186] Where U2(t) represents the target voltage at time t; U1(t) represents the difference between the control voltage and the disturbance compensation voltage; Indicates the control voltage; Indicates the disturbance compensation voltage; k A0 =L q / ρ;e c (t) represents the current difference between the desired control current and the actual control current, e c (t)=i q (t)-O(t), i q O(t) represents the desired control current of the q-axis of the motor, and O(t) represents the actual control current of the q-axis of the motor; k A1 =(2L) q +Rτ) / ρτ;k A2 =(L q +2τR) / (ρτ) 2 ;k A3 =R / (ρτ) 2 ;k B0 =2L q / τ;k B1 =(L q +2τR) / τ 2 ;k B2 =R / τ 2 L qρ represents the q-axis inductance of the motor; R represents the stator resistance of the motor; ρ represents the dynamic response coefficient; τ represents the preset parameter that determines the bandwidth of the current tracking module and the disturbance suppression module; t, l, and h represent different integration times; Q(s) represents the original transfer function of the disturbance suppression module; GR(s) represents the transfer function of the harmonic suppression module after it is embedded in the controlled object.

[0187] In some other possible embodiments, the harmonic suppression module satisfies the following formula:

[0188]

[0189] Where, U(s) k U(s) represents the target voltage output by the harmonic suppression module at time k. k-1 E(s) represents the target voltage output by the harmonic suppression module at time k-1. k This represents the control voltage and disturbance compensation voltage input to the harmonic suppression module at time k; ω h ω represents the resonant frequency of the harmonic suppression module. c The cutoff frequency of the harmonic suppression module is represented by s; s represents the Laplace operator; α represents the order; k f L represents the gain coefficient; q R represents the q-axis inductance of the motor; R represents the stator resistance of the motor.

[0190] In some other possible embodiments, the processing unit 1002 is specifically used to perform inverse Park transformation on the target voltage to obtain a three-phase AC signal; perform space vector pulse width modulation on the three-phase AC signal to obtain a pulse width modulation waveform; and control the switching state of the three-phase inverter through the pulse width modulation waveform to generate a corresponding duty cycle to control the motor.

[0191] In an exemplary embodiment, this application also provides an electronic device that can be applied to the above-described motor control device. Figure 11 This is a schematic diagram illustrating the composition of an electronic device provided in an embodiment of this application. For example... Figure 11 As shown, the electronic device may include a processor 1101 and a memory 1102.

[0192] Processor 1101 is used to execute instructions stored in memory 1102 to implement the motor control method provided in the above embodiments of this application. Processor 1101 may be a CPU, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller (MCU) / single-chip microcomputer / microcontroller, a programmable logic device (PLD), or any combination thereof. Processor 1101 may also be any other device with processing functions, such as a circuit, device, or software module, which is not limited in this embodiment.

[0193] The memory 1102 can be used to store instructions, software programs, or various data executable by the processor 1101. The memory 1102 may primarily include a program storage area and a data storage area. The program storage area may store the operating system, application programs required by at least one functional module (such as a determination unit, processing unit, etc.), etc. Furthermore, the memory 1102 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0194] It should be noted that those skilled in the art will understand that Figure 11 The electronic device structure shown does not constitute a limitation on the electronic device; the electronic device may include, but is not limited to, other electronic devices. Figure 11 This may indicate more or fewer components, or combinations of certain components, or different component arrangements.

[0195] In an exemplary embodiment, this application also provides a readable storage medium including software instructions that, when executed in an electronic device, cause the electronic device to implement the methods described above.

[0196] Optionally, the readable storage medium may be a non-transitory computer-readable storage medium, such as a read-only memory (ROM), random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device.

[0197] In an exemplary embodiment, this application also provides a computer program product that, when run in an electronic device, causes the electronic device to implement the methods described in the above embodiments.

[0198] It should be noted that when one or more instructions in the computer-readable storage medium or computer program product are executed by the processor of an electronic device, they implement the various processes of the above method embodiments and achieve the same technical effect as the above method. To avoid repetition, they will not be described again here.

[0199] Through the above description of the embodiments, those skilled in the art can clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0200] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another apparatus, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0201] The units described as separate components may or may not be physically separate. A component shown as a unit can be one or more physical units; that is, it can be located in one place or distributed in multiple different locations. Some or all of the classified units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0202] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0203] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiments of this application, essentially, or the part that contributes to the prior art, or a complete or partial classification of the technical solution, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0204] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A motor control method, characterized in that, The method includes: Obtain the desired control current and actual control current of the motor; A control voltage is generated based on the current difference between the desired control current and the actual control current using a current tracking module. The disturbance suppression module generates a disturbance compensation voltage based on the actual control current and the internal model principle. The target voltage is generated using the harmonic suppression module based on the control voltage and the disturbance compensation voltage; The motor is controlled to operate based on the target voltage.

2. The method according to claim 1, characterized in that, The transfer function of the current tracking module satisfies the following formula: Where GA(s) represents the transfer function of the current tracking module; D ry (s) represents the transfer function describing the current loop tracking trajectory, D ry (s) = 1 / (ρs+1), where ρ represents the dynamic response coefficient; s represents the Laplace operator; Q m (s) represents the update transfer function of the disturbance suppression module; P n (s) represents the mathematical model of the motor; Where R(s) represents the control function of the harmonic suppression module; Q(s) represents the original transfer function of the disturbance suppression module; Where, k f ω represents the gain coefficient; s represents the Laplace operator; α represents the order; ω h ω represents the resonant frequency of the harmonic suppression module. c This indicates the cutoff frequency of the harmonic suppression module; Wherein, τ represents a preset parameter that determines the bandwidth of the current tracking module and the disturbance suppression module.

3. The method according to claim 1, characterized in that, The transfer function of the disturbance suppression module satisfies the following formula: Where GB(s) represents the transfer function of the disturbance suppression module; Q(s) represents the original transfer function of the disturbance suppression module; P n (s) represents the mathematical model of the motor; Q m (s) represents the update transfer function of the disturbance suppression module; Wherein, R(s) represents the control function of the harmonic suppression module; Where, k f ω represents the gain coefficient; s represents the Laplace operator; α represents the order; ω h ω represents the resonant frequency of the harmonic suppression module. c This indicates the cutoff frequency of the harmonic suppression module; Wherein, τ represents a preset parameter that determines the bandwidth of the current tracking module and the disturbance suppression module.

4. The method according to claim 1, characterized in that, The transfer function of the harmonic suppression module satisfies the following formula: Wherein, GR(s) represents the transfer function of the harmonic suppression module after it is embedded in the controlled object; k f ω represents the gain coefficient; s represents the Laplace operator; α represents the order; ω h ω represents the resonant frequency of the harmonic suppression module. c L represents the cutoff frequency of the harmonic suppression module; q This represents the q-axis inductance of the motor.

5. The method according to claim 1, characterized in that, For the q-axis of the motor, the generation of a target voltage using the harmonic suppression module based on the control voltage and the disturbance compensation voltage includes: The target voltage is generated according to the following formula: U2(t)=[1+Q(s)+GR(s)]U1(t); Wherein, U2(t) represents the target voltage at time t; U1(t) represents the difference between the control voltage and the disturbance compensation voltage; This refers to the control voltage; Indicates the disturbance compensation voltage; k A0 =L q / ρ;e c (t) represents the current difference between the desired control current and the actual control current, e c (t)=i q (t)-O(t), i q O(t) represents the desired control current of the q-axis of the motor, and O(t) represents the actual control current of the q-axis of the motor; k A1 =(2L) q +Rτ) / ρτ;k A2 =(L q +2τR) / (ρτ) 2 ;k A3 =R / (ρτ) 2 ;k B0 =2L q / τ;k B1 =(L q +2τR) / τ 2 ;k B2 =R / τ 2 L q R represents the q-axis inductance of the motor; R represents the stator resistance of the motor; ρ represents the dynamic response coefficient; τ represents the preset parameter that determines the bandwidth of the current tracking module and the disturbance suppression module; t, l, and h represent different integration durations; Q(s) represents the original transfer function of the disturbance suppression module; GR(s) represents the transfer function of the harmonic suppression module after it is embedded in the controlled object.

6. The method according to claim 1, characterized in that, The harmonic suppression module satisfies the following formula: Where, U(s) k U(s) represents the target voltage output by the harmonic suppression module at time k. k-1 E(s) represents the target voltage output by the harmonic suppression module at time k-1. k This represents the control voltage and disturbance compensation voltage input to the harmonic suppression module at time k; ω h ω represents the resonant frequency of the harmonic suppression module. c The cutoff frequency of the harmonic suppression module is represented by s; s represents the Laplace operator; α represents the order; k f L represents the gain coefficient; q R represents the q-axis inductance of the motor; R represents the stator resistance of the motor.

7. The method according to any one of claims 1-6, characterized in that, The method of controlling the motor operation based on the target voltage includes: The target voltage is subjected to inverse Park transform to obtain a three-phase AC signal; Space vector pulse width modulation is performed on the three-phase AC signal to obtain the pulse width modulation waveform; The switching state of the three-phase inverter is controlled by the pulse width modulation waveform, and the corresponding duty cycle is generated to control the motor.

8. A motor control device, characterized in that, The device includes: an acquisition unit and a processing unit; The acquisition unit is used to acquire the desired control current and the actual control current of the motor. The processing unit is configured to: generate a control voltage using a current tracking module based on the current difference between the desired control current and the actual control current; generate a disturbance compensation voltage using a disturbance suppression module based on the actual control current and the internal model principle; generate a target voltage using a harmonic suppression module based on the control voltage and the disturbance compensation voltage; and control the motor operation based on the target voltage.

9. An electronic device, characterized in that, include: Processor and memory; The memory stores instructions that the processor can execute; When the processor is configured to execute the instructions, the electronic device performs the method as described in any one of claims 1-7.

10. A readable storage medium, characterized in that, include: Software instructions; When the software instructions are executed in an electronic device, the electronic device causes the electronic device to perform the method as described in any one of claims 1-7.

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