A motor control method, system, device and computer readable storage medium

Abstract

The application discloses a motor control method, system, device and computer readable storage medium, comprising obtaining the running state parameter of the FOC system; the running state parameter comprises at least one of the control loop internal state quantity, the thermal state quantity and the running mode flag; determining the running condition of the FOC system based on the running state parameter; in response to the running condition, adjusting the gate drive voltage of the power switch device of the FOC system; controlling the power switch device based on the adjusted gate drive voltage to drive the motor to run. The application can match the gate drive voltage with the differentiated requirements of different running conditions on the switching speed and conduction loss, so as to realize the balance between the conduction loss, switching loss and electromagnetic interference, and improve the overall performance of the FOC system.

Description

Technical Field

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

[0002] In field-oriented control (FOC) systems for electric motors, three-phase inverters typically employ power switching devices such as MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) or IGBTs (Insulated-Gate Bipolar Transistors). These devices are driven to turn on and off via high-frequency PWM (Pulse-Width Modulation) signals, converting the DC bus voltage into three-phase AC power to drive the motor. The gate drive voltage of the power switching devices directly determines their on-resistance and switching speed, thus affecting the FOC system's conduction losses, switching losses, electromagnetic interference (EMI), and current sampling accuracy. However, most current FOC systems use a single, fixed gate drive voltage. Since the motor's requirements for switching speed and conduction losses vary under different operating conditions, a fixed gate drive voltage cannot be dynamically adjusted according to the motor's actual operating conditions. This makes it difficult to achieve a balance between conduction losses, switching losses, and EMI, thereby limiting the performance of the FOC system.

[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, system, device, and computer-readable storage medium to at least solve the problems in the related art, such as the use of a single fixed gate drive voltage, the inability to dynamically adjust it according to the actual operating conditions of the motor, and the difficulty in achieving a balance between conduction loss, switching loss, and electromagnetic interference.

[0005] To solve the above-mentioned technical problems, this application provides a motor control method, including: Obtain the operating status parameters of the FOC system; the operating status parameters include at least one of the following: internal state variables of the control loop, thermal state variables, and operating mode flags. The operating conditions of the FOC system are determined based on the aforementioned operating status parameters. In response to the operating conditions, the gate drive voltage of the power switching devices in the FOC system is adjusted; The power switching device is controlled based on the adjusted gate drive voltage to drive the motor.

[0006] Optionally, in response to the operating condition, adjusting the gate drive voltage of the power switching device in the FOC system includes: When the operating condition is the current zero-crossing condition, the current sampling window for the FOC system to sample the phase current within the PWM cycle is determined; Within the current sampling window, the gate drive voltage of the power switching device is adjusted from a non-sampling voltage to a sampling voltage, wherein the sampling voltage is less than the non-sampling voltage; After the current sampling window ends, the gate drive voltage of the power switching device is restored from the sampled voltage to the non-sampled voltage.

[0007] Optionally, within the current sampling window, adjusting the gate drive voltage of the power switching device from a non-sampling voltage to a sampling voltage, wherein the sampling voltage is less than the non-sampling voltage, includes: During a first time interval before the arrival of the current sampling window, the gate drive voltage of the power switching device is adjusted from a non-sampling voltage to a sampling voltage. During a second time interval during which the current sampling window lasts, the gate drive voltage is maintained at the sampling voltage. After the current sampling window ends, restoring the gate drive voltage of the power switching device from the sampled voltage to the non-sampled voltage includes: In the third time interval after the current sampling window ends, the gate drive voltage is restored to the non-sampled voltage.

[0008] Optionally, in response to the operating condition, adjusting the gate drive voltage of the power switching device in the FOC system includes: Based on the operating conditions corresponding to the control cycle, the target value of the gate drive voltage of the power switching device is determined; the control cycle includes multiple consecutive PWM cycles. In each PWM cycle within the control cycle, the voltage change rate corresponding to the power switching device is detected. If the voltage change rate is not within a preset safety range, the target value of the gate drive voltage is corrected so that the voltage change rate is within the preset safety range.

[0009] Optionally, based on the operating conditions corresponding to the control cycle, the target value of the gate drive voltage of the power switching device is determined, including: For the operating conditions corresponding to the control cycle, optimization weights are determined for multiple optimization objectives corresponding to the operating conditions; the multiple optimization objectives include conduction loss, switching loss, electromagnetic interference level, and current sampling accuracy. Based on the optimized weights and the operating state parameters within the control cycle, the target value of the gate drive voltage is obtained.

[0010] Optionally, the operating status parameters include torque current feedback value, modulation ratio, junction temperature prediction of the power switching device, and excitation current feedback value, and the optimization weights include first optimization weight, second optimization weight, third optimization weight, and fourth optimization weight; Based on the optimized weights and the operating state parameters within the control cycle, the target value of the gate drive voltage is obtained, including: The target value of the gate drive voltage is calculated using the first relation, which is: ; in, The target value of the gate drive voltage. As the reference drive voltage, For the first optimization weight, The torque current feedback value is... This is the rated torque current. For the second optimization weight, The modulation ratio is... For the third optimization weight, The estimated junction temperature is... For reference temperature, For the fourth optimization weight, The excitation current function characterizes the depth of field weakening.

[0011] Optionally, the internal state variables of the control loop include torque current feedback value, excitation current feedback value, torque current command value, excitation current command value, modulation ratio, and current regulator output parameters; the thermal state variables include the junction temperature prediction of the power switching device; and the operating mode flag includes the current zero-crossing flag. Determining the operating conditions of the FOC system based on the aforementioned operating status parameters includes: Based on the operating state parameters, the operating condition is determined to be at least one of the following: low-speed high-torque condition, weak magnetic field condition, light-load high-efficiency condition, and current zero-crossing condition.

[0012] This application also provides a motor control system, including: The acquisition module is used to acquire the operating status parameters of the FOC system; the operating status parameters include at least one of the following: internal state variables of the control loop, thermal state variables, and operating mode flags. The determination module is used to determine the operating conditions of the FOC system based on the operating status parameters. An adjustment module is used to adjust the gate drive voltage of the power switching device of the FOC system in response to the operating conditions. A control module is used to control the power switching device based on the adjusted gate drive voltage to drive the motor.

[0013] This application also provides an electronic device, including: Memory, used to store computer programs; A processor for executing the computer program to implement the steps of the motor control method as described in any of the above.

[0014] 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.

[0015] This application achieves a solution where, since the obtained internal state variables, thermal state variables, and operating mode flags of the control loop all characterize the actual operating state of the FOC system, the operating condition determined based on these parameters can accurately reflect the current operating condition of the motor. Consequently, the gate drive voltage is adjusted in response to this operating condition, so that the gate drive voltage no longer maintains a single fixed value but changes with the actual operating condition of the motor. This solves the technical problems in related technologies, such as the use of a single fixed gate drive voltage, the inability to dynamically adjust according to the actual operating condition of the motor, and the difficulty in achieving a balance between conduction loss, switching loss, and electromagnetic interference. This allows the gate drive voltage to match the differentiated requirements of switching speed and conduction loss under different operating conditions, thereby achieving a balance between conduction loss, switching loss, and electromagnetic interference, and improving the overall performance of the FOC system. Attached Figure Description

[0016] 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.

[0017] Figure 1 A schematic diagram of the overall structure of a power switching device gate drive voltage closed-loop regulation system based on FOC state feedback provided in an embodiment of this application; Figure 2 This is a flowchart illustrating the steps of a motor control method provided in an embodiment of this application. Figure 3 A schematic diagram of a driving circuit for a power switching device provided in an embodiment of this application; Figure 4This is a schematic diagram of a PWM and sampling window provided in an embodiment of this application; Figure 5 This is a schematic diagram of a fixed gate drive voltage in related technologies; Figure 6 A schematic diagram of a gate drive voltage under zero-current conditions provided in an embodiment of this application; Figure 7 This is a schematic diagram of the structure of a motor control system provided in an embodiment of this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following description, in conjunction with the accompanying drawings and embodiments, provides a more detailed explanation of a motor control method, system, device, and computer-readable storage medium provided in this application. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0019] The FOC system involved in this application refers to a motor control system that achieves independent control similar to that of a DC motor by decoupling the stator current and independently controlling the torque current and excitation current. It is widely used in permanent magnet synchronous motors (PMSMs) and brushless DC motors (BLDCs). In this FOC system, the three-phase inverter is composed of power switching devices such as MOSFETs or IGBTs. The FOC controller drives each power switching device to turn on and off through a high-frequency PWM signal, converting the DC bus voltage into three-phase AC power to drive the motor. The gate drive voltage Vgs of a power switching device directly determines its on-resistance Rds(on) and switching speed. A higher gate drive voltage results in lower on-resistance and conduction losses, suitable for high-current operation. However, excessively fast switching speeds lead to excessively high drain voltage change rates dv / dt and current change rates di / dt, causing severe electromagnetic interference (EMI) and voltage spikes, which can even damage the power switching device. Conversely, a lower gate drive voltage slows down the switching speed, reduces dv / dt and di / dt, and suppresses EMI and voltage spikes. However, it increases on-resistance and conduction losses, leading to heat generation under heavy loads. Therefore, the value of the gate drive voltage needs to be carefully balanced among multiple performance indicators such as conduction losses, switching losses, EMI levels, and current sampling accuracy. With the widespread adoption of wide-bandgap semiconductors such as SiC (Silicon Carbide) and GaN (Gallium Nitride), the switching speed of power switching devices is getting faster and faster, and the drawbacks of a single fixed gate drive voltage scheme are becoming more prominent. The solution proposed in this application is more suitable for such high-speed devices.

[0020] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the overall structure of a closed-loop regulation system for the gate drive voltage of a power switching device based on FOC state feedback, provided as an embodiment of this application. The system mainly includes an FOC controller, an operating condition discrimination module, a drive voltage calculation module, a programmable gate drive circuit, a dv / dt detection circuit, a feedback correction module, a power switching device, and a motor.

[0021] The FOC controller generates PWM signals to drive the power switching devices while simultaneously calculating and outputting a series of internal parameters characterizing the system's operating state in real time, including but not limited to the torque current feedback value iq, the excitation current feedback value id, and the torque current command value iq. Excitation current command value id The system receives key information such as modulation ratio M, estimated junction temperature Tj of the power switch, current regulator output parameters, and current zero-crossing flag. After receiving these operating status parameters, the operating condition discrimination module identifies the specific operating condition of the system using a preset algorithm. Based on the identified operating condition and combined with an internally integrated multi-objective optimization model, the drive voltage calculation module comprehensively considers multiple objectives such as conduction loss, switching loss, EMI level, and current sampling accuracy to calculate the theoretically optimal target value Vgs_opt for that operating condition. The programmable gate drive circuit, based on the received instruction including Vgs_opt, outputs the corresponding actual drive voltage to the gate of the power switch, thereby controlling the turn-on and turn-off characteristics of the power switch.

[0022] The dv / dt detection circuit continuously monitors the voltage change rate of the switching node of the power switching device, which can be located at the drain of the power switching device. In a three-phase inverter, a dv / dt detection circuit is set for each phase to collect the voltage change rate of the switching node of the power switching device in that phase, serving as the feedback signal for the inner loop. The feedback correction module compares the detected voltage change rate with the preset safety range allowed by the system in real time. If the detected voltage change rate exceeds the preset safety range, it indicates that the current drive voltage may be too high or the switching speed may be too fast. At this time, the feedback correction module immediately corrects Vgs_opt downwards and reissues it to reduce the gate drive voltage, thereby suppressing the excessive voltage change rate. As the core power switch of the system, the power switching device can be a MOSFET in this application. The voltage change rate of its drain is monitored in real time by the dv / dt detection circuit, and information such as the source current can be used as one of the bases for the FOC controller to generate PWM signals and output internal state parameters. As the driven object, the motor receives three-phase AC power output from the three-phase inverter. Its actual speed, position and other information are fed back to the FOC controller for closed-loop control of the FOC algorithm, which in turn indirectly affects the adjustment decision of the gate drive voltage.

[0023] Structurally, the above system forms two closed loops: an inner loop and an outer loop. The inner loop is... Figure 1 The dashed box at the bottom center includes a three-phase inverter built with power switching devices, a feedback correction module, a dv / dt detection circuit, a programmable gate drive circuit, and a motor, used to achieve fast closed-loop control of the switching transients of the power switching devices. The outer loop is... Figure 1 The dashed box at the top center consists of the FOC controller, the operating condition discrimination module, and the drive voltage calculation module, and is used for cross-cycle adaptive optimization based on the operating conditions of the FOC system. Several embodiments are described in detail below.

[0024] This embodiment provides a motor control method, which can be executed by a main controller. The main controller can be, but is not limited to, an execution entity with computing capabilities such as an MCU (Microcontroller Unit), DSP (Digital Signal Processor), or FPGA (Field-Programmable Gate Array). Figure 2 As shown, the motor control method includes the following steps: S101: Obtain the operating status parameters of the FOC system; the operating status parameters include at least one of the following: internal state variables of the control loop, thermal state variables, and operating mode flags.

[0025] Among them, the internal state variables of the control loop refer to the internal variables generated by the control loop of the FOC system during operation, characterizing the control states such as the current loop or speed loop; the thermal state variables refer to the quantities characterizing the temperature state of the power switching devices, such as the junction temperature prediction; and the operating mode flags refer to the flag bits that identify the specific operating mode or specific moment of the FOC system, such as the current zero-crossing flag. In one implementation, the master controller reads the torque current feedback value iq, the excitation current feedback value id, and the torque current command value iq from the FOC controller in each PWM cycle. Excitation current command value id The parameters include the bus voltage Vbus, the estimated junction temperature Tj of the power switching devices, the modulation ratio M, and the output value of the current regulator. As an optional embodiment, a switching frequency of 20kHz corresponds to a PWM period of 50 microseconds. It should be noted that the above parameters are all derived from the operating status of the FOC system itself, and can more realistically and meticulously reflect the current operating conditions of the motor.

[0026] S102: Determine the operating conditions of the FOC system based on operating status parameters.

[0027] The main controller determines the current operating condition of the FOC system based on the acquired operating status parameters and through preset discrimination logic. The operating condition is used to characterize the current operating situation of the motor, such as the load, whether it is in the field weakening speed expansion stage, and whether it is near the current zero crossing point.

[0028] S103: Adjusts the gate drive voltage of the power switching devices in the FOC system in response to operating conditions.

[0029] The main controller adjusts the gate drive voltage of the power switching device according to the determined operating conditions, so that the gate drive voltage changes with the operating conditions and no longer maintains a single fixed value.

[0030] S104: Controls power switching devices based on adjusted gate drive voltage to drive motor operation.

[0031] The actual driving voltage is applied to the gate of the power switching device according to the adjusted gate driving voltage. Under the control of the PWM signal, the power switching device is turned on and off, thereby inverting the DC bus voltage into three-phase AC power to drive the motor.

[0032] In one embodiment, the adjustment and output of the gate drive voltage in steps S103 and S104 above can be implemented by a low-cost programmable gate drive circuit, such as... Figure 3 As shown, the drive voltage calculation module first calculates the target value Vgs_opt of the gate drive voltage in the aforementioned manner, with a value range of 6~16V. This module does not directly output this target value; instead, based on a pre-set mapping relationship corresponding to the input and output transmission characteristics of the adjustable power supply chip, it converts the target value Vgs_opt into an analog control voltage Vset and outputs it. The value range of Vset is 0~3.3V. The adjustable low-dropout linear regulator or charge pump generates a corresponding supply voltage Vdrv based on this analog control voltage Vset, for example, adjustable from 6~16V. The gate driver uses Vdrv as its supply voltage and converts the PWM signal into a gate drive voltage Vgs_act with an amplitude equal to Vdrv, which is applied to the gate of the power switching device. Thus, continuous and smooth adjustment of the gate drive voltage within the 6~16V range can be achieved through the analog quantity Vset, with voltage resolution reaching the millivolt level, improved linearity, and avoidance of voltage jumps and control discontinuities that may occur during gear switching. This programmable gate drive circuit does not require complex digital encoding and decoding logic, has simple hardware, and the drive voltage calculation and feedback correction logic can be implemented by software of ordinary MCU or FPGA, which is low cost and easy to integrate with existing FOC controllers or motor drive boards.

[0033] As an alternative embodiment for generating the analog control voltage Vset, a digital-to-analog converter circuit composed of a digital potentiometer and an operational amplifier can also be used to generate Vset. The digital potentiometer is controlled through the MCU's I2C (Inter-Integrated Circuit) or SPI (Serial Peripheral Interface) interface. Its output resistance is amplified by the operational amplifier and level-converted to obtain the desired Vset voltage. This embodiment offers more flexible digital control, and the resolution can be adjusted by selecting digital potentiometers with different bit depths. However, the linearity may be slightly inferior to the direct analog control method, and the circuit complexity is slightly increased. Furthermore, it should be noted that the power switching device in this application is not limited to MOSFETs; it can also be IGBTs, as well as wide-bandgap semiconductor devices such as SiC and GaN.

[0034] In this embodiment, since the acquired internal state variables, thermal state variables, and operating mode flags of the control loop all characterize the actual operating state of the FOC system, the operating condition determined based on the above operating state parameters can truly reflect the current operating condition of the motor. Therefore, the gate drive voltage is adjusted in response to this operating condition, so that the gate drive voltage no longer maintains a single fixed value but changes with the actual operating condition of the motor. This solves the technical problems in related technologies, such as using a single fixed gate drive voltage, being unable to dynamically adjust according to the actual operating condition of the motor, and finding it difficult to balance conduction losses, switching losses, and electromagnetic interference. This allows the gate drive voltage to match the differentiated requirements of switching speed and conduction losses under different operating conditions, thereby achieving a balance between conduction losses, switching losses, and electromagnetic interference, and improving the overall performance of the FOC system.

[0035] In an exemplary embodiment, the internal state variables of the control loop include torque current feedback value, excitation current feedback value, torque current command value, excitation current command value, modulation ratio, and current regulator output parameters; the thermal state variables include the estimated junction temperature of the power switching device; and the operating mode flags include the current zero-crossing flag. The operating conditions of the FOC system are determined based on operating status parameters, including: Based on the operating status parameters, the operating conditions are determined to be at least one of the following: low-speed high-torque condition, field weakening condition, light-load high-efficiency condition, and current zero-crossing condition.

[0036] This embodiment further explains the specific composition of the operating state parameters and the method for determining the operating condition. The internal state variables of the control loop include, but are not limited to, the torque current feedback value iq, the excitation current feedback value id, and the torque current command value iq. Excitation current command value id , modulation ratio M, and output parameters of the current regulator. The thermal state quantity includes the estimated junction temperature Tj of the power switch device, and the operation mode flag includes the current zero-crossing flag. The above operation state parameters jointly constitute multi-dimensional state information, enabling the working condition discrimination to no longer rely on a single or a few external electrical quantities, but to be able to describe the operation characteristics inside the FOC system.

[0037] Specifically, when iq is much larger than id and close to the rated value, and at the same time the modulation ratio M is low, the system is judged to be in the low-speed high-torque working condition. When it is detected that id is negative and its absolute value increases with the increase of the speed, and the modulation ratio M is close to 1, it is judged to be in the field-weakening working condition. If the absolute values of both iq and id are small, the system is in the light-load high-efficiency working condition. And when the current zero-crossing flag is set, the system recognizes the current zero-crossing working condition.

[0038] In one implementation, several thresholds can be pre-calibrated. For example, let the torque current threshold Iq1 = 50A, Iq2 = 10A, Iq3 = 2A, and the field current negative threshold be 5A. Then the discrimination rules include but are not limited to: When the absolute value of the torque current command value |iq | > Iq1, it is judged to be in the low-speed high-torque working condition. In this working condition, the motor needs to output a relatively large torque current and the speed is low; When the field current feedback value id < -5A, that is, id is negative and its absolute value increases with the increase of the speed, and the modulation ratio M is close to 1, it is judged to be in the field-weakening working condition. This working condition is used to expand the speed range of the motor when the bus voltage is limited; When Iq2 < |iq | ≤ Iq1 and it does not belong to the field-weakening working condition, it is judged to be in the light-load high-efficiency working condition. This working condition mainly pursues the energy utilization efficiency; When |iq | < Iq3 and the current zero-crossing flag is true, it is judged to be in the current zero-crossing working condition. In this working condition, the phase current is close to zero and is easily affected by the dead-time effect and switching noise.

[0039] In one implementation, the working condition area discrimination module can comprehensively analyze the above operation state parameters by using an algorithm based on rules or fuzzy logic, and map the continuous operation states to several working condition areas with clear characteristics. Based on the fine working condition recognition, the main controller can adjust the subsequent gate drive voltage regulation strategy specifically, making the regulation more in line with the core requirements of the current working condition.

[0040] To avoid frequent switching of operating conditions due to slight parameter fluctuations near the operating condition boundary, which could cause target voltage jitter, in one embodiment, hysteresis can be introduced at the aforementioned thresholds. For example, a threshold Iq1 is used to enter the low-speed, high-torque operating condition, while a threshold slightly smaller than Iq1 is used to exit the operating condition, thereby improving the stability of operating condition discrimination. Furthermore, since the aforementioned operating state parameters comprehensively reflect multiple dimensions such as torque current, excitation current, modulation ratio, junction temperature, and current zero crossing, operating condition discrimination can distinguish complex situations that are difficult to differentiate with a single parameter, such as a large torque current coupled with a high modulation ratio. For example, when the torque current is large and the modulation ratio M is also high, it is more likely to be classified as a transitional operating condition that takes into account speed expansion requirements, rather than a simple low-speed, high-torque operating condition, thus making subsequent drive voltage adjustment more precise. It should be noted that the aforementioned thresholds, hysteresis, and the four types of operating conditions listed in this embodiment are merely examples and can be calibrated according to the actual motor rated parameters and application scenarios. Adding, merging, or subdividing operating conditions without departing from the concept of this application all fall within the scope of protection of this application.

[0041] In one exemplary embodiment, adjusting the gate drive voltage of the power switching device in the FOC system in response to operating conditions includes: When the operating condition is the current zero-crossing condition, determine the current sampling window for the FOC system to sample the phase current within the PWM cycle; Within the current sampling window, the gate drive voltage of the power switching device is adjusted from the non-sampling voltage to the sampling voltage, and the sampling voltage is less than the non-sampling voltage. After the current sampling window ends, the gate drive voltage of the power switching device is restored from the sampling voltage to the non-sampling voltage.

[0042] This embodiment describes the adjustment of the gate drive voltage of the power switching devices in the FOC system under the current zero-crossing condition. It is understood that the FOC system requires high sampling accuracy for the phase current. Current sampling is typically performed within a specific time window within the PWM cycle, such as the stable interval after the lower bridge arm is turned on. However, the switching noise of the power switching devices can severely interfere with the current signal within the sampling window. Therefore, in this embodiment, when operating under the current zero-crossing condition, the current sampling window for the FOC system to sample the phase current within the PWM cycle is first determined. This current sampling window is set by the FOC controller based on parameters such as dead time and the switching delay of the power switching devices to ensure that the three-phase current is in a stable state at the sampling time.

[0043] Because the absolute value of the current is very small near the zero-crossing point of the phase current, the current distortion caused by switching noise and dead zone effect accounts for a larger proportion of the actual current signal, and its impact on sampling accuracy is more prominent. The current near the zero-crossing point is the key basis for FOC coordinate transformation and current loop decoupling. Its sampling error will be directly transmitted to the estimation deviation between the torque current feedback value iq and the excitation current feedback value id, which will cause torque pulsation and speed fluctuation. Therefore, under this operating condition, the effect of suppressing the switching noise in the sampling window is better.

[0044] Within the current sampling window, the gate drive voltage of the power switching device is adjusted from the non-sampling voltage to the sampling voltage, with the sampling voltage being lower than the non-sampling voltage. In other words, the gate drive voltage is actively reduced during the sampling window, slowing down the switching speed of the power switching device. This reduces switching noise, voltage change rate, and current change rate within the current sampling window, preventing these noises from interfering with the sampling circuit's accurate measurement of the phase current.

[0045] After the current sampling window ends, the gate drive voltage of the power switching device is restored from the sampled voltage to the non-sampled voltage. That is, a higher non-sampled voltage is quickly restored after the sampling window ends to maintain switching efficiency. In one embodiment, the FOC controller sends a window synchronization signal to the programmable gate drive circuit when the current sampling window arrives, and the programmable gate drive circuit quickly switches between the sampled voltage and the non-sampled voltage accordingly.

[0046] It should be noted that a current sampling window is set within each PWM cycle, and multiple sampling windows typically exist within the same control cycle. However, in this embodiment, the gate drive voltage is reduced only when the operating condition is determined to be a current zero-crossing condition. Under non-current zero-crossing conditions, there is no need to specifically reduce the drive voltage for the current sampling window. This embodiment actively reduces switching noise within the current sampling window, improving the signal-to-noise ratio and accuracy of current sampling, providing accurate current feedback for the FOC algorithm, thereby improving the control quality of the current loop and reducing torque fluctuations and speed instability during motor operation. Simultaneously, restoring the normal gate drive voltage outside the sampling window ensures that the power switching devices operate at high efficiency for most of the operating time, achieving a balance between noise suppression and operating efficiency.

[0047] In one exemplary embodiment, within a current sampling window, adjusting the gate drive voltage of the power switching device from a non-sampling voltage to a sampling voltage, wherein the sampling voltage is less than the non-sampling voltage, includes: During the first time interval before the arrival of the current sampling window, the gate drive voltage of the power switching device is adjusted from the non-sampling voltage to the sampling voltage. During the second time interval during which the current sampling window lasts, the gate drive voltage is kept at the sampling voltage. After the current sampling window ends, the gate drive voltage of the power switching device is restored from the sampled voltage to the non-sampled voltage, including: In the third time interval after the current sampling window ends, the gate drive voltage is restored to the non-sampling voltage.

[0048] This embodiment provides a specific implementation method for the switching timing of the gate drive voltages inside and outside the sampling window. Please refer to... Figures 4-6 , Figures 4-6 This is a schematic diagram of the key timing coordination under the current zero-crossing condition, where Figure 4 This shows the position of the current sampling window during the PWM cycle. Figure 5 This illustrates a scenario where, under a fixed drive voltage scheme, strong switching noise exists within the sampling window, leading to fluctuations and even distortion in the sampled values. Figure 6 This embodiment demonstrates the effect of actively reducing the driving voltage within the sampling window on smoothing the sampling waveform and improving sampling accuracy. The specific switching timing includes: In this embodiment, during a first time interval before the arrival of the current sampling window, the gate drive voltage of the power switching device is adjusted from a non-sampling voltage to a sampling voltage; during a second time interval during the duration of the current sampling window, the gate drive voltage is maintained at the sampling voltage. In other words, switching begins a first time interval before the start of the sampling window to ensure that the gate drive voltage is stable at the sampling voltage at the start of the current sampling window and remains at that sampling voltage throughout the entire duration of the current sampling window.

[0049] After a third time interval following the end of the current sampling window, the gate drive voltage is quickly restored to the non-sampling voltage to prepare for normal operation in the next switching cycle. In one embodiment, the first time interval can be, for example, 50 ns, the second time interval (i.e., the sampling window duration) can be, for example, 1 μs, and the third time interval can be, for example, 50 ns; the non-sampling voltage can be, for example, 12V, and the sampling voltage can be, for example, 8V. Through the above precise three-stage timing control, noise within the sampling window is minimized while avoiding efficiency loss due to prolonged reduction of the drive voltage, achieving a balance between noise suppression and operating efficiency. The above values ​​are merely examples and can be adjusted according to device characteristics and sampling requirements.

[0050] For example, assuming a switching frequency of 20kHz and a corresponding PWM period of 50μs, the target value of the gate drive voltage calculated by the outer loop is 12V, i.e., the non-sampling voltage Vgs_normal = 12V. To suppress switching noise during the sampling period, the sampling voltage is set to Vgs_sample = 8V, satisfying 8V < 12V. The sampling window is located in the stable region after the lower bridge arm is turned on, with a duration of t2 = 1μs.

[0051] Before the current sampling window arrives, t1 = 50 ns, the target value of the gate drive voltage is switched from 12V to 8V to ensure that the current sampling window is stable at 8V at the beginning of the current sampling window. Within the current sampling window, t2 = 1μs, the target value of the gate drive voltage is maintained at Vgs_sample = 8V. At this time, the switching speed is slowed down, dv / dt and noise are greatly reduced, and the phase current sampling waveform is smooth. After the current sampling window ends at t3 = 50 ns, the target value of the gate drive voltage is restored from 8V to Vgs_normal = 12V to prepare for the rest of the cycle and normal operation in the next cycle.

[0052] As an alternative to sampling window switching timing control, besides sending a synchronization signal from the FOC controller to the programmable gate drive circuit, a timer can be integrated inside the gate drive circuit. This timer triggers the switching timing of the gate drive voltage based on the rising or falling edge of the received PWM signal. This alternative reduces the burden on the FOC controller and enables local autonomous control of the drive circuit.

[0053] In one exemplary embodiment, adjusting the gate drive voltage of the power switching device in the FOC system in response to operating conditions includes: Based on the operating conditions corresponding to the control cycle, the target value of the gate drive voltage of the power switching device is determined; the control cycle includes multiple consecutive PWM cycles. In each PWM cycle within the control cycle, the voltage change rate corresponding to the power switching device is detected. If the voltage change rate is not within the preset safe range, the target value of the gate drive voltage is corrected so that the voltage change rate is within the preset safe range.

[0054] This embodiment provides a specific implementation of a dual-loop regulation method for adjusting the gate drive voltage in response to operating conditions, comprising two parts: outer loop regulation and inner loop regulation, wherein: The outer loop adjustment includes determining the target value of the gate drive voltage of the power switching device based on the operating conditions corresponding to the control cycle. The control cycle includes multiple consecutive PWM cycles. It is understood that the main controller does not redetermine the target value of the gate drive voltage in every PWM cycle, but rather determines the target value based on the operating conditions corresponding to a control cycle containing multiple consecutive PWM cycles. The number N of PWM cycles in the control cycle can be configured according to the rate of load change. In one implementation, it can be set to re-determine the operating conditions and calculate the target value every 10 to 100 PWM cycles. The operating conditions corresponding to the control cycle can be determined by statistically processing the operating state parameters of multiple PWM cycles within that control cycle, such as by taking the average value, but not limited to the average value; other mathematical statistical methods such as weighted average and median can also be used. The outer loop adjustment can adaptively adjust the target value of the gate drive voltage according to operating conditions such as slow load changes and switching of motor operating regions.

[0055] The inner-loop regulation includes: in each PWM cycle within the control cycle, detecting the voltage change rate corresponding to the power switching device; if the voltage change rate is not within a preset safe range, correcting the target value of the gate drive voltage to bring the voltage change rate within the preset safe range. Specifically, when the power switching device is turned on or off under the control of the PWM signal, the dv / dt detection circuit immediately collects the change rate of its drain voltage and sends it to the feedback correction module. The feedback correction module compares it with the preset safe range, which can be defined by a preset safe boundary, such as 15V / ns as the safe upper limit of the voltage change rate. This safe upper limit can be set comprehensively based on the rated parameters of the power switching device, circuit parasitic parameters, and EMI suppression requirements. If the actual voltage change rate exceeds the preset safe range, the feedback correction module lowers the target value of the gate drive voltage by a preset step size, which takes effect for the remaining time of the current PWM cycle. The preset step size can be 0.5V. If the voltage still exceeds the preset safe range after lowering, it continues to lower it by the preset step size until the voltage change rate falls back into the safe range. This inner-loop correction process can occur in every switching transient, forming a negative feedback closed loop. The response time is typically less than 500 nanoseconds, much less than a PWM cycle, enabling timely response to sudden switching transient anomalies within a single PWM cycle.

[0056] In hardware implementation, one embodiment of the dv / dt detection circuit can connect the drain of the power switching device to a high-speed comparator via a resistor divider network. The resistor divider network can be configured as follows: Figure 3 The diagram shows the configuration of R1 and R2. The output of the high-speed comparator is sent as a trigger signal to the fast interrupt pin of the MCU or FPGA, thereby triggering a fast correction of the inner loop when the voltage change rate exceeds a threshold, such as... Figure 3As shown. As an alternative, a dedicated dv / dt detection chip can also be used. This type of chip integrates voltage divider, comparator, and trigger circuits, which can detect the drain voltage change rate more accurately and quickly, simplifying the external circuit and improving detection consistency and reliability.

[0057] For ease of understanding, an exemplary process for inner-loop correction is given below. Assume the outer loop determines the target value of the gate drive voltage to be 15V based on the current operating conditions, with a preset safety boundary of 15V / ns and a preset step size of 0.5V. When the voltage change rate measured by the dv / dt detection circuit during a switching transient is 18V / ns, it is determined to exceed the preset safety boundary. The feedback correction module immediately lowers the target value from 15V to 14.5V by 0.5V, and this adjustment takes effect for the remainder of the current PWM cycle. If the voltage change rate measured after driving at 14.5V is still 16V / ns, still exceeding the preset safety boundary, the voltage is further lowered by 0.5V to 14V; this process iterates until the voltage change rate falls back below 15V / ns. Since the above iteration can be completed within a single PWM cycle, with a response time of less than 500 nanoseconds, there is no need to wait for the next switching cycle to constrain the switching transient within the safe range, avoiding voltage overshoot, oscillation, and EMI exceeding limits.

[0058] In addition, as an alternative to dual-loop feedback correction, the inner loop dv / dt feedback can directly adjust the target value with a fixed step size, or it can use a proportional-integral (PI) control algorithm to calculate a continuous adjustment value based on the deviation of the voltage change rate, making the control of the voltage change rate smoother. The outer loop's adaptive operating condition can be re-executed every N cycles, or it can be triggered by events. When a large change in key state parameters of the FOC system, such as torque current, excitation current, and speed, exceeding a set threshold is detected, a new round of operating condition identification and target value calculation is immediately triggered to respond to sudden changes in operating conditions more promptly. However, the trigger threshold needs to be set reasonably to avoid frequent triggering that could lead to system instability.

[0059] Therefore, the outer loop performs cross-cycle adaptive optimization of operating conditions on a control cycle basis, providing dynamically changing target values ​​for the inner loop. The inner loop then performs rapid closed-loop correction of switching transients within each PWM cycle. The inner loop's corrections take effect within the current PWM cycle, without waiting for the next switching cycle, thus enabling timely responses to switching transient anomalies caused by sudden load changes or parasitic parameter drift. This overcomes the deficiency in related technologies where quasi-closed-loop structures require a full switching cycle delay for adjustment. It should be further noted that in this embodiment, the outer loop sets a reference for the inner loop. The inner loop fine-tunes in real time around this reference to ensure the safety of switching transients. When the outer loop updates the target value of the gate drive voltage in the next control cycle, the inner loop continues transient correction based on the new target value. This embodiment enables the FOC system to achieve multi-objective optimization following changes in operating conditions while simultaneously suppressing voltage overshoot and EMI in real time, improving the performance and reliability of the FOC system.

[0060] In an exemplary embodiment, determining the target value of the gate drive voltage of the power switching device based on the operating conditions corresponding to the control cycle includes: For the operating conditions corresponding to the control cycle, the optimization weights are determined for multiple optimization objectives corresponding to the operating conditions; the multiple optimization objectives include conduction loss, switching loss, electromagnetic interference level and current sampling accuracy; Based on the optimized weights and the operating state parameters within the control cycle, the target value of the gate drive voltage is obtained.

[0061] In this embodiment, the optimization weight allocation for each optimization objective is implemented with reference to the mapping table shown in Table 1.

[0062] Table 1 Mapping Table of Operating Conditions and Weight Allocation

[0063] This embodiment determines the optimization weights allocated to each optimization objective under the identified operating condition by looking up a table, thus determining the optimal target value under that operating condition. Specifically, different operating conditions emphasize different performance indicators: under low-speed, high-torque conditions, since a large current needs to be output, optimization focuses on reducing conduction losses and ensuring sufficient current output capability, thus allocating a higher optimization weight to conduction losses, making the target value relatively higher to reduce on-resistance; under weak magnetic field conditions, switching losses and EMI are the main considerations, thus allocating a higher optimization weight to switching losses and EMI levels, making the target value moderate, achieving a balance between switching losses and voltage change rate suppression; under light-load, high-efficiency conditions, priority is given to reducing total losses, including conduction losses and switching losses, so the target value can be relatively lower; under conditions involving current sampling, such as current zero crossing, improving current sampling accuracy is the primary objective, and driving parameters are optimized to reduce dead-zone effects and current distortion.

[0064] Considering that related technologies often struggle to simultaneously consider multiple performance indicators when setting the gate drive voltage, they typically optimize one or two objectives, such as efficiency or EMI, based on typical operating conditions during the design phase. Once the operating conditions deviate from the design point, the overall performance deteriorates. This application's drive voltage calculation module integrates a multi-objective optimization model that dynamically adjusts the optimization weights for objectives such as conduction loss, switching loss, EMI level, and current sampling accuracy based on different identified operating conditions. For example, under low-speed, high-torque conditions, priority is given to reducing conduction loss; under weak field conditions, the focus is on balancing switching loss and EMI; under light-load, high-efficiency conditions, the overall loss is comprehensively reduced; and within the current sampling window, improving sampling accuracy is the primary objective. Through this dynamic switching mechanism of multiple objectives, this application can achieve the comprehensive optimization of various performance indicators across the entire operating range of the motor.

[0065] In an exemplary embodiment, the operating state parameters include torque current feedback value, modulation ratio, estimated junction temperature of power switching device, and excitation current feedback value, and the optimization weights include a first optimization weight, a second optimization weight, a third optimization weight, and a fourth optimization weight. Based on the optimized weights and the operating state parameters during the control cycle, the target value of the gate drive voltage is obtained, including: Using the first relation, calculate the target value of the gate drive voltage. The first relation is: ; in, The target value for the gate drive voltage. As the reference drive voltage, As the first optimization weight, This is the torque current feedback value. This is the rated torque current. As the second optimization weight, The modulation ratio, For the third optimization weight, For the estimated junction temperature, For reference temperature, For the fourth optimization weight, The excitation current function characterizes the depth of field weakening.

[0066] In this embodiment, the operating state parameters include the torque current feedback value, modulation ratio, estimated junction temperature of the power switching device, and excitation current feedback value; the optimization weights include a first optimization weight, a second optimization weight, a third optimization weight, and a fourth optimization weight. The step of obtaining the target value of the gate drive voltage based on the optimization weights and the operating state parameters within the control cycle specifically includes: calculating the target value of the gate drive voltage using a first relational expression. The first relational expression is: ; Wherein, Vgs_opt is the target value of the gate drive voltage, Vgs_base is the reference drive voltage (i.e., the default gate drive voltage), k1 is the first optimization weight, iq is the torque current feedback value, iq_rated is the torque current rating, k2 is the second optimization weight, M is the modulation ratio, k3 is the third optimization weight, Tj is the estimated junction temperature, T_ref is the reference temperature, k4 is the fourth optimization weight, and f(id) is the excitation current function characterizing the field weakening depth. In one embodiment, f(id) can be a function of the excitation current, for example, taking a form related to the square of id to reflect the field weakening depth, and when id is negative, it indicates that the field is in a field weakening state.

[0067] As shown in the first relation, the larger the torque current feedback value iq, the heavier the load, and the higher the target value under the first term, in order to reduce the on-resistance and conduction loss. The larger the modulation ratio M, the closer it is to the field weakening / high-speed region, and the lower the target value under the second term, in order to suppress excessively fast switching speed and EMI. The higher the junction temperature prediction Tj, the higher the target value is under the third term, in order to take into account the thermal safety of the device. The excitation current function f(id) is used to correct the target value under field weakening conditions. The values ​​of each optimization weight k1, k2, k3, and k4 can be switched according to the operating conditions. For example, k1 is larger under low-speed, high-torque conditions, and k2 is larger under light-load, high-efficiency conditions, thus reflecting different optimization focuses under different operating conditions. In addition, for the current zero-crossing condition, the target value Vgs_opt can be divided into two values: a lower sampling voltage Vgs_sample is used within the current sampling window, and a higher non-sampling voltage Vgs_normal is used outside the sampling window.

[0068] In one implementation, the estimated junction temperature Tj can be obtained as follows: Measure the drain-source voltage Vds and current Id when the power switching device is turned on; calculate its on-resistance using the formula Rds(on) = Vds / Id; and then, based on the temperature and resistance characteristic curves in the device datasheet, deduce the corresponding estimated junction temperature Tj. This eliminates the need for an additional temperature sensor, facilitating engineering implementation.

[0069] Assuming the operating state parameters are based on the control cycle, if the operating condition is determined to be low-speed, high-torque, then the values ​​of k1, k2, k3, and k4 are 60%, 15%, 10%, and 15%, respectively. If the operating condition is determined to be weak magnetic field, then the values ​​of k1, k2, k3, and k4 are 30%, 25%, 30%, and 15%, respectively. If the operating condition is determined to be light-load, high-efficiency, then the values ​​of k1, k2, k3, and k4 are 10%, 35%, 40%, and 15%, respectively. If the operating condition is determined to be zero-crossing current, then the values ​​of k1, k2, k3, and k4 are 10%, 20%, 20%, and 50%, respectively.

[0070] For example, assume the reference drive voltage Vgs_base=12V, the torque current rating iq_rated=40A, the reference temperature T_ref=25°C, the gate drive voltage limiting range is 6~16V, and the excitation current function f(id) takes the form of being related to the square of id, and f(id)=0 when id=0.

[0071] Within a certain control cycle, the main controller reads the operating status parameters from the FOC controller and obtains them statistically over multiple PWM cycles as follows: torque current feedback value iq = 36A, modulation ratio M = 0.3, junction temperature prediction Tj = 45°C, and excitation current feedback value id = 0A. Tj is obtained by calculating the on-resistance from the drain-source voltage Vds and current Id measured within that cycle using Rds(on) = Vds / Id, and then deducing it from the temperature-resistance curve.

[0072] Operating condition determination: The torque current is relatively large, 36A, which is 90% of the rated value, while the modulation ratio is low, M=0.3, corresponding to a low speed. Therefore, the operating condition for this control cycle is determined to be low speed and high torque.

[0073] Referring to Table 1, the low-speed, high-torque operating condition corresponds to k1=60%, k2=15%, k3=10%, and k4=15%, which simplifies to k1=0.60, k2=0.15, k3=0.10, and k4=0.15. Substituting these values ​​into the first equation yields... This value is within the 6~16V limiting range, therefore the target value of the gate drive voltage Vgs_opt = 14.5V. It can be seen that under low speed and high torque conditions, the weight k1 corresponding to the conduction loss is the largest, which is 60%. The first term increases the target value, thereby reducing the on-resistance Rds(on) of the power switching device and reducing the conduction loss and heat generation under high current.

[0074] In each PWM cycle, the dv / dt detection circuit monitors the voltage change rate of the switching node of the power switching device in real time. If the detected voltage change rate is 13V / ns when driven at 14.5V, which is within the preset safety range, no correction is made, and the gate drive voltage remains at 14.5V. If the detected voltage change rate exceeds 15V / ns during a switching transient, the feedback correction module lowers the target value by a preset step size within the current PWM cycle, such as reducing it to 14.0V, and re-outputs Vset accordingly until the voltage change rate falls back to the preset safety range.

[0075] Therefore, in this embodiment, under low-speed, high-torque conditions, a weighted combination with conduction loss as the primary factor is obtained by looking up a table. A relatively high target gate drive voltage of 14.5V is calculated using the first relational formula. This minimizes conduction loss and heat generation under high-current conditions while ensuring transient switching safety, demonstrating the beneficial effects of dynamic adjustment based on operating conditions and multi-objective weighted optimization. Other operating conditions are processed using the same procedure, only the values ​​of k1 to k4 obtained from the table lookup differ.

[0076] Please refer to Figure 7 This application also provides a motor control system, including: Module 1 is used to acquire the operating status parameters of the FOC system; the operating status parameters include at least one of the following: internal state variables of the control loop, thermal state variables, and operating mode flags. Module 2 is used to determine the operating conditions of the FOC system based on the operating status parameters; Adjustment module 3 is used to adjust the gate drive voltage of the power switching devices in the FOC system in response to operating conditions; Control module 4 is used to control the power switching device based on the adjusted gate drive voltage to drive the motor.

[0077] In specific implementation, the acquisition module can correspond to the aforementioned FOC controller and its parameter reading interface; the determination module can correspond to the operating condition zone discrimination module; the adjustment module can correspond to the drive voltage calculation module, feedback correction module, and programmable gate drive circuit; and the control module can correspond to the part that controls the power switching device via a PWM signal under the adjusted gate drive voltage. All of the above modules can be implemented entirely or partially through software, hardware, or a combination of both, for example, by executing corresponding programs using an MCU, DSP, or FPGA. The modules can also be subdivided or merged in one step. This motor control system can implement the corresponding steps of the above embodiments and has the same beneficial effects as the method, which will not be elaborated further here.

[0078] This application also provides an electronic device, including: Memory, used to store computer programs; A processor is used to execute computer programs to implement motor control methods as described above.

[0079] In one embodiment, the electronic device can be a motor driver, a motor control board, or a control device integrating the above-mentioned functions. The processor can be an MCU, DSP, FPGA, general-purpose central processing unit, or application-specific integrated circuit, etc., and the memory can be a read-only memory, random access memory, flash memory, etc. The processor and memory can be connected via a bus. The processor reads and executes the computer program stored in the memory to implement the steps of the above-mentioned motor control method, thereby realizing the dynamic adjustment of the gate drive voltage according to the operating conditions. This electronic device has the same beneficial effects as the above-mentioned motor control method.

[0080] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the motor control method described above.

[0081] In one embodiment, the computer-readable storage medium may include various media capable of storing computer programs, such as a USB flash drive, portable hard drive, read-only memory, random access memory, magnetic disk, or optical disk. When the computer program is loaded and executed by a processor, the processor can perform the steps of the motor control method described above. This computer-readable storage medium has the same beneficial effects as the motor control method described above.

[0082] 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.

[0083] 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 motor control method, characterized in that, include: Obtain the operating status parameters of the FOC system; the operating status parameters include at least one of the following: internal state variables of the control loop, thermal state variables, and operating mode flags. The operating conditions of the FOC system are determined based on the aforementioned operating status parameters. In response to the operating conditions, the gate drive voltage of the power switching devices in the FOC system is adjusted; The power switching device is controlled based on the adjusted gate drive voltage to drive the motor.

2. The motor control method according to claim 1, characterized in that, In response to the operating conditions, adjusting the gate drive voltage of the power switching devices in the FOC system includes: When the operating condition is the current zero-crossing condition, the current sampling window for the FOC system to sample the phase current within the PWM cycle is determined; Within the current sampling window, the gate drive voltage of the power switching device is adjusted from a non-sampling voltage to a sampling voltage, wherein the sampling voltage is less than the non-sampling voltage; After the current sampling window ends, the gate drive voltage of the power switching device is restored from the sampled voltage to the non-sampled voltage.

3. The motor control method according to claim 2, characterized in that, Within the current sampling window, adjusting the gate drive voltage of the power switching device from a non-sampling voltage to a sampling voltage, wherein the sampling voltage is less than the non-sampling voltage, includes: During a first time interval before the arrival of the current sampling window, the gate drive voltage of the power switching device is adjusted from a non-sampling voltage to a sampling voltage. During a second time interval during which the current sampling window lasts, the gate drive voltage is maintained at the sampling voltage. After the current sampling window ends, restoring the gate drive voltage of the power switching device from the sampled voltage to the non-sampled voltage includes: In the third time interval after the current sampling window ends, the gate drive voltage is restored to the non-sampled voltage.

4. The motor control method according to claim 1, characterized in that, In response to the operating conditions, adjusting the gate drive voltage of the power switching devices in the FOC system includes: Based on the operating conditions corresponding to the control cycle, the target value of the gate drive voltage of the power switching device is determined; the control cycle includes multiple consecutive PWM cycles. In each PWM cycle within the control cycle, the voltage change rate corresponding to the power switching device is detected. If the voltage change rate is not within a preset safety range, the target value of the gate drive voltage is corrected so that the voltage change rate is within the preset safety range.

5. The motor control method according to claim 4, characterized in that, Based on the operating conditions corresponding to the control cycle, the target value of the gate drive voltage of the power switching device is determined, including: For the operating conditions corresponding to the control cycle, optimization weights are determined for multiple optimization objectives corresponding to the operating conditions; the multiple optimization objectives include conduction loss, switching loss, electromagnetic interference level, and current sampling accuracy. Based on the optimized weights and the operating state parameters within the control cycle, the target value of the gate drive voltage is obtained.

6. The motor control method according to claim 5, characterized in that, The operating status parameters include torque current feedback value, modulation ratio, junction temperature prediction of the power switching device, and excitation current feedback value. The optimization weights include first optimization weight, second optimization weight, third optimization weight, and fourth optimization weight. Based on the optimized weights and the operating state parameters within the control cycle, the target value of the gate drive voltage is obtained, including: The target value of the gate drive voltage is calculated using the first relation, which is: ; in, The target value of the gate drive voltage. As the reference drive voltage, For the first optimization weight, The torque current feedback value is... This is the rated torque current. For the second optimization weight, The modulation ratio is... For the third optimization weight, The estimated junction temperature is... For reference temperature, For the fourth optimization weight, The excitation current function characterizes the depth of field weakening.

7. The motor control method according to any one of claims 1-6, characterized in that, The internal state variables of the control loop include torque current feedback value, excitation current feedback value, torque current command value, excitation current command value, modulation ratio, and current regulator output parameters. The thermal state variables include the junction temperature prediction of the power switching device. The operating mode flags include the current zero-crossing flag. Determining the operating conditions of the FOC system based on the aforementioned operating status parameters includes: Based on the operating state parameters, the operating condition is determined to be at least one of the following: low-speed high-torque condition, weak magnetic field condition, light-load high-efficiency condition, and current zero-crossing condition.

8. A motor control system, characterized in that, include: The acquisition module is used to acquire the operating status parameters of the FOC system; the operating status parameters include at least one of the following: internal state variables of the control loop, thermal state variables, and operating mode flags. The determination module is used to determine the operating conditions of the FOC system based on the operating status parameters. An adjustment module is used to adjust the gate drive voltage of the power switching devices of the FOC system in response to the operating conditions. A control module is used to control the power switching device based on the adjusted gate drive voltage to drive the motor.

9. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor, configured to implement the steps of the motor control method as described in any one of claims 1-7 when executing the computer program.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the motor control method as described in any one of claims 1-7.

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