A brushless motor system and control method

Abstract

This invention relates to the field of brushless motor technology, and discloses a brushless motor system and control method, including a sampling module; a hybrid observer for real-time sampling of motor terminal voltage, line current, and current slope, and predicting rotor position using an adaptive algorithm; a dynamic commutation compensation module for real-time detection of motor line current and back EMF waveforms, and adjustment of commutation angle and PWM duty cycle; an adaptive controller responsible for signal processing, adaptive startup, and PWM generation; and an inverter for driving the brushless motor according to the PWM control signal. This invention achieves high-precision rotor position estimation under sensorless conditions through a hybrid observer design. The hybrid observer integrates back EMF detection and current slope estimation, effectively compensating for noise caused by freewheeling current, eliminating phase lag and chattering caused by the low-pass filter in traditional sliding mode observers, and improving the accuracy of rotor position information.

Description

Technical Field

[0001] This invention belongs to the field of brushless motor technology, specifically relating to a brushless motor system and control method. Background Technology

[0002] Brushless DC motors, with their superior performance such as high efficiency, low noise, and long lifespan, are increasingly widely used in industrial and consumer fields such as aerospace, robotics, automotive electronics, and home appliances. Precise control of brushless motors relies on accurate detection of the rotor position to achieve sequential commutation of the stator windings and generate driving torque.

[0003] In the area of ​​position sensor-based control, CN202334412U discloses a "brushless DC motor control system." This system includes a position sensor, a DSP controller, and drive and inverter circuits. The position sensor is mounted on the motor stator to detect the rotor's position information during operation and sends it to the DSP controller. The DSP controller calculates the real-time rotational speed based on adjacent position information and the acquisition time interval, compares the real-time speed with a preset target speed, and sends a PWM control signal to the drive and inverter circuits based on the comparison result. The drive and inverter circuits control the motor's speed and rotation direction according to the control signal. This solution utilizes the high-performance data processing capabilities and rich peripheral interfaces of the DSP to achieve brushless DC motor control based on a speed closed-loop, exhibiting good anti-interference performance and stable operation. However, this technical solution still relies on physical position sensors. The installation of the sensors increases the motor's size and manufacturing cost, and the reliability of the sensors decreases in harsh environments such as high temperatures and oil contamination, limiting the motor's application in certain special situations.

[0004] In the field of sensorless control, CN114337398A discloses a "sensorless control system and method for brushless DC motors." This system includes a speed PI controller, a current PI controller, a PWM module, a three-phase inverter module, an improved SMO module, a current comparison module, a logic judgment module, and a commutation signal module. This scheme uses the current comparison module to detect the terminal voltage and DC-side voltage, obtains the commutation freewheeling signal, and converts it into a clean zero-crossing signal, eliminating freewheeling interference during commutation. Simultaneously, an improved sliding mode observer is used to observe the line back EMF, eliminating the need for the low-pass filter and phase compensation stage required by traditional SMOs, thus eliminating chattering. This scheme solves the problems of commutation interference and observation accuracy to a certain extent. However, when the motor is stationary or running at low speed, the back EMF signal is weak, still facing difficulties in initial position estimation. Open-loop starting or other auxiliary measures are usually required, and the smoothness and reliability of the starting process need further improvement.

[0005] Therefore, there is an urgent need for a brushless motor system and control method that can solve the problems of commutation freewheeling interference, sliding mode observer jitter, and sensorless start-up difficulties. Summary of the Invention

[0006] The purpose of this invention is to provide a brushless motor system and control method to solve the problems of commutation freewheeling interference, sliding mode observer jitter, and sensorless start-up difficulties.

[0007] Based on the above concept, the technical solution adopted by this invention is as follows: According to a first aspect of the present invention, a brushless motor system is provided, comprising: Sampling module; used to acquire the terminal voltage signal and line current signal of the brushless motor in real time; Hybrid observer; used to sample motor terminal voltage, line current, and current slope in real time, and use adaptive algorithms to predict rotor position; Dynamic commutation compensation module; used to detect motor line current and back EMF waveforms in real time, and adjust commutation angle and PWM duty cycle; Adaptive controller; responsible for signal processing, adaptive startup, and PWM generation; And an inverter; used to drive a brushless motor according to a PWM control signal.

[0008] In some embodiments, the hybrid observer includes: Back EMF sampling module is used to estimate motor speed and position; The current slope detection module is used to obtain the instantaneous current slope; And an adaptive algorithm module, which is used to predict and output the real-time position information of the rotor and the commutation advance angle.

[0009] In some embodiments, the adaptive controller includes an adaptive startup module for generating an open-loop high-frequency excitation signal and adjusting the PWM duty cycle.

[0010] In some embodiments, the dynamic commutation compensation module monitors the change in freewheeling current of the non-conducting phase at the commutation moment in real time; Based on the current motor load and speed status, the optimal commutation advance angle is calculated using an adaptive compensation algorithm and output to the adaptive controller.

[0011] In some embodiments, the output of the sampling module is electrically connected to the hybrid observer, and the input is electrically connected to the brushless motor; The first output terminal of the hybrid observer is electrically connected to the dynamic commutation compensation module, and the second output terminal is electrically connected to the adaptive controller. The output of the dynamic commutation compensation module is electrically connected to the adaptive controller; The output of the adaptive controller is electrically connected to the inverter; The inverter is electrically connected to the input terminal of the brushless motor.

[0012] In some embodiments, the brushless motor system further includes a fault detection module; The fault detection module includes current, voltage, and temperature sensors for monitoring current, voltage, and temperature parameters.

[0013] According to a second aspect of the present invention, a brushless motor system control method is provided, comprising the following steps: S1. When the system is powered on, the sampling module collects the terminal voltage signal and line current signal of the motor in a stationary state and sends them to the hybrid observer. S2. The hybrid observer determines the initial commutation angle based on the terminal voltage signal and the line current signal, and sends it to the adaptive controller; S3. The adaptive controller generates a high-frequency excitation signal based on the initial commutation angle, drives the inverter to output a high-frequency rotating magnetic field, and enables the rotor to obtain initial position information. S4. The adaptive controller controls the inverter to drive the motor rotation in an open-loop excitation mode. At the same time, the sampling module collects the terminal voltage signal and line current signal in real time and sends them to the hybrid observer. S5. The hybrid observer, based on the real-time acquired terminal voltage signal and line current signal, outputs the real-time rotor position information to the adaptive controller and dynamic commutation compensation module by fusing back electromotive force and current slope information. S6. When the motor speed reaches the preset threshold, the adaptive controller gradually adjusts the PWM duty cycle according to the real-time rotor position information, so that the motor transitions from open-loop excitation mode to closed-loop control mode. S7. During the closed-loop operation phase, the dynamic commutation compensation module detects the freewheeling current of the non-conducting phase and calculates the commutation advance angle based on the line current signal collected in real time by the sampling module and the rotor real-time position information output by the hybrid observer, and outputs it to the adaptive controller. S8. The adaptive controller generates a PWM control signal based on the real-time rotor position information and the commutation advance angle to drive the inverter to achieve precise commutation control.

[0014] In some embodiments, the process of mixing the real-time rotor position information output by the observer in step S5 includes: Acquire voltage and current signals; Filter the voltage signal and calculate the slope of the current signal; Calculate the back electromotive force and its rate of change; Output the real-time rotor position information and commutation advance angle.

[0015] In some embodiments, step S9 is also included. The fault detection module monitors current, voltage, and temperature signals; When an anomaly is detected, the protection mechanism is triggered, and a shutdown or current limiting signal is output. After the fault is recovered, it will re-enter the closed-loop operation state.

[0016] The beneficial effects of this invention are as follows: 1. This invention achieves high-precision rotor position estimation under sensorless conditions through a hybrid observer design. The hybrid observer integrates back EMF detection and current slope estimation to effectively compensate for noise caused by freewheeling current, eliminating phase lag and chattering caused by the low-pass filter in traditional sliding mode observers, and improving the accuracy of rotor position information.

[0017] 2. This invention uses an adaptive start-up strategy to apply a high-frequency rotating magnetic field to the hybrid observer when the motor is stationary, providing initial position information. After the speed reaches a preset threshold, it smoothly transitions to closed-loop control mode, avoiding the defect of traditional open-loop start-up methods that are prone to losing steps when the load changes. This achieves smooth start-up of the motor across the entire speed range from standstill to high-speed operation. Attached Figure Description

[0018] Figure 1 This is an overall block diagram of the brushless motor control system of the present invention; Figure 2 This is a flowchart of the hybrid observer algorithm of the present invention; Figure 3 This is a flowchart of the adaptive startup module of the present invention; Figure 4 This is the control logic flowchart of the present invention. Detailed Implementation

[0019] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0020] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise defined, the technical or scientific terms used in this application should be understood in their ordinary sense by one of ordinary skill in the art to which this invention pertains. The words “a” or “one” and similar terms used in this application specification and claims do not indicate a limitation of quantity, but rather indicate the presence of at least one. “A plurality” means two or more. The words “comprising” or “including” and similar terms mean that the element or object preceding “comprising” or “including” covers the element or object listed following “comprising” or “including” and its equivalents, and does not exclude other elements or objects. The words “connected” or “linked” and similar terms are not limited to physical or mechanical connections and can include electrical connections, whether direct or indirect. The words “above” and / or “below” and similar terms are for ease of description only and are not limited to a location or spatial orientation. The singular forms “a,” “the,” and “the” used in this application specification and appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0021] The technical concept of this invention includes: In the field of brushless motor control technology, existing sensor-based control schemes require the installation of physical position sensors such as Hall elements on the motor stator. This not only increases the size and manufacturing cost of the motor but also makes it prone to failure or performance degradation under harsh conditions such as high temperature, oil contamination, and vibration, thus limiting the application range of the motor. Sensorless control technology, developed to address these issues, eliminates the need for physical sensors, but still faces several technical challenges in practical applications: First, freewheeling interference during commutation leads to inaccurate commutation signals, causing torque pulsation; second, traditional sliding mode observers suffer from phase lag and chattering due to low-pass filters, affecting the accuracy of back EMF observation; third, the back EMF signal is weak when the motor is stationary, making it difficult to accurately detect the rotor's initial position, resulting in starting difficulties. These intertwined problems make it difficult for existing sensorless control schemes to achieve high-precision, high-stability rotor position estimation and commutation control across the entire speed range.

[0022] To address the aforementioned technical shortcomings, this invention proposes a sensorless control technology based on hybrid observation. The core of this concept lies in using a hybrid observer that integrates back EMF detection and current slope estimation. An adaptive algorithm is employed to fuse the data from both in real time, effectively compensating for noise interference caused by freewheeling current. Simultaneously, it eliminates the phase lag and chattering issues inherent in traditional sliding mode observers due to low-pass filters, thus achieving high-precision rotor position estimation without sensors. Furthermore, an adaptive start-up strategy is introduced. A high-frequency rotating magnetic field is applied when the motor is stationary to provide initial position information to the hybrid observer. Once the speed reaches a preset threshold, the system smoothly transitions to closed-loop control mode, solving the start-up challenge. Simultaneously, dynamic commutation compensation logic is employed to detect the freewheeling current in the non-conducting phase in real time and dynamically adjust the commutation angle and PWM duty cycle, significantly reducing torque ripple during commutation.

[0023] Based on the above technical concept, this invention achieves a unified system of high-precision rotor position estimation, smooth start-up, and low-pulsation commutation control under sensorless conditions through the synergistic effect of a hybrid observer, an adaptive start-up strategy, and dynamic commutation compensation logic. Therefore, the technical concept of this invention lies in constructing a complete sensorless control system that systematically addresses the shortcomings of existing technologies from three levels: position estimation, start-up control, and commutation compensation, providing a reliable technical solution for the efficient and stable operation of brushless motors across the entire speed range.

[0024] This application provides a brushless motor system, including Sampling module; used to acquire the terminal voltage signal and line current signal of the brushless motor in real time; Hybrid observer; used to sample motor terminal voltage, line current, and current slope in real time, and use adaptive algorithms to predict rotor position; Dynamic commutation compensation module; used to detect motor line current and back EMF waveforms in real time, and adjust commutation angle and PWM duty cycle; Adaptive controller; responsible for signal processing, adaptive startup, and PWM generation; And an inverter; used to drive a brushless motor according to a PWM control signal.

[0025] This invention achieves high-precision rotor position estimation under sensorless conditions through a hybrid observer design. The hybrid observer integrates back EMF detection and current slope estimation to effectively compensate for noise caused by freewheeling current, eliminating phase lag and chattering caused by the low-pass filter in traditional sliding mode observers, and improving the accuracy of rotor position information.

[0026] The following is in conjunction with the appendix Figures 1 to 4 This application provides a detailed description of a brushless motor system and control method.

[0027] like Figure 1 As shown in the figure, this embodiment provides a brushless motor system, including a sampling module, a hybrid observer, a dynamic commutation compensation module, an adaptive controller, and an inverter.

[0028] The sampling module's input is connected to the three-phase output of the brushless motor, used to acquire the terminal voltage and line current signals during the brushless motor's operation in real time. The sampling module internally includes voltage sampling circuits and current sampling circuits. The voltage sampling circuit acquires the three-phase terminal voltage, and the current sampling circuit acquires the three-phase line current. After converting the acquired analog signals into digital signals, the sampling module sends them to the hybrid observer through its output. The sampling frequency of the sampling module is set according to the motor's maximum operating speed, ensuring that at least 20 points are acquired within one electrical cycle to meet the data resolution requirements of subsequent algorithms.

[0029] The input of the hybrid observer is connected to the output of the sampling module to receive the voltage and line current signals. The hybrid observer includes a back EMF sampling module, a current slope detection module, and an adaptive algorithm module.

[0030] The back EMF sampling module estimates the back EMF and its rate of change based on the received terminal voltage signal and the voltage equation of the brushless motor. The current slope detection module calculates the instantaneous current slope based on the received line current signal using a differential or derivative algorithm. Because the current signal contains high-frequency noise, the current slope detection module first performs digital filtering to eliminate the amplified effect of measurement noise on the derivative calculation, and then uses a backward differential or center differential method to calculate the derivative of the current with respect to time. The current slope detection module outputs the filtered instantaneous current slope to the adaptive algorithm module, which also outputs the real-time rotor position information and commutation advance angle. These two signals are simultaneously sent to the adaptive controller and the dynamic commutation compensation module.

[0031] The input of the dynamic commutation compensation module is connected to the output of the hybrid observer, and it indirectly acquires the line current signal through a sampling module. Its output is connected to the adaptive controller. The dynamic commutation compensation module is a software algorithm module implemented within the adaptive controller to solve the freewheeling interference problem during commutation.

[0032] The core function of the dynamic commutation compensation module is to detect the freewheeling current of the non-conducting phase and calculate the commutation advance angle. When the motor commutates, due to the winding inductance, a freewheeling current flows through the non-conducting phase, causing distortion of the terminal voltage waveform and interfering with normal commutation detection. The dynamic commutation compensation module determines the freewheeling state by monitoring the changes in the terminal voltage of the non-conducting phase: when the terminal voltage of the non-conducting phase is clamped above the bus voltage or below ground level, it is determined to be in a freewheeling state, and the duration of the freewheeling is recorded. Based on the freewheeling duration and the current speed, the dynamic commutation compensation module uses an adaptive compensation algorithm to calculate the commutation advance angle. The longer the freewheeling time, the larger the required commutation advance angle; the higher the speed, the larger the electrical angle corresponding to the same freewheeling time. The dynamic commutation compensation module outputs the calculated commutation advance angle to the adaptive controller.

[0033] The input of the adaptive controller is connected to the output of the hybrid observer and the output of the dynamic commutation compensation module, while its output is connected to the control terminal of the inverter. The adaptive controller is implemented using a digital signal processor or microcontroller and integrates multiple functional modules, including an adaptive startup module, a PWM generation module, and speed loop and current loop control modules.

[0034] The adaptive start module addresses the challenge of sensorless starting of brushless motors. When the motor is stationary, the back electromotive force (EMF) is zero, making it impossible to obtain the rotor position using a hybrid observer. The adaptive start module first applies a high-frequency voltage excitation signal and preliminarily determines the initial rotor position by analyzing the current response. Subsequently, the adaptive start module controls the inverter to output a rotating magnetic field corresponding to the initial position, using an open-loop method to start the rotor. As the rotor speed increases, the back EMF gradually strengthens, and the estimation accuracy of the hybrid observer gradually improves. When the motor speed reaches a preset threshold and the position estimation error output by the hybrid observer stabilizes within the allowable range, the adaptive start module switches the control mode from open-loop start to closed-loop control, achieving a smooth transition.

[0035] The adaptive controller generates six PWM control signals based on the rotor position information output by the hybrid observer, the commutation advance angle output by the dynamic commutation compensation module, and the voltage commands output by the speed loop and current loop. The adaptive controller employs space vector pulse width modulation (SVM) or sinusoidal pulse width modulation (SVM), with a fixed carrier frequency of 10kHz or higher. The commutation advance angle is used to correct the phase of the PWM signal; specifically, it adds a compensation angle to the direction of the synthesized voltage vector based on the rotor position, thereby advancing or delaying the commutation time and offsetting the effects of freewheeling interference.

[0036] The inverter's control terminal is connected to the PWM output pin of the adaptive controller, and its power output terminal is connected to the three-phase input terminal of the brushless motor. The inverter receives six PWM control signals from the adaptive controller and controls the energizing state of each phase winding according to the duty cycle and timing of the PWM signals, converting the DC bus voltage into a three-phase AC voltage with adjustable frequency and amplitude to drive the motor to rotate.

[0037] This embodiment also includes a fault detection module. The input of the fault detection module is connected to the sampling module and receives signals from the temperature sensor. The output is connected to the adaptive controller. The fault detection module monitors the bus voltage, three-phase current, and controller temperature in real time. When it detects abnormal conditions such as overvoltage, undervoltage, overcurrent, or overtemperature, it sends a fault signal to the adaptive controller. Upon receiving the fault signal, the adaptive controller immediately blocks the PWM output to protect the system. After the fault is cleared, the system can resume operation through a reset or automatic retry.

[0038] This embodiment provides a brushless motor system control method, including the following steps S1 to S8. The steps are described in detail below in conjunction with the connection relationship and working principle of each module of the system.

[0039] Step S1: The system is powered on, and the sampling module collects the terminal voltage signal and line current signal of the motor in a stationary state and sends them to the hybrid observer.

[0040] After the system powers on, the adaptive controller first performs initialization configuration, including clock settings, I / O port configuration, PWM module configuration, ADC module configuration, and interrupt vector configuration. Once initialization is complete, the adaptive controller triggers the sampling module to begin operation.

[0041] The input of the sampling module is connected to the three-phase output of the brushless motor, at which point the motor is stationary. The sampling module internally includes voltage and current sampling circuits, which synchronously sample the three-phase terminal voltages and three-phase line currents, respectively. Since the motor is stationary, the acquired terminal voltage signals mainly consist of common-mode noise and offset voltage, while the line current signal is a small bias current that is zero or close to zero.

[0042] The sampling module converts the acquired analog signals into digital signals and sends them to the input of the hybrid observer through its output. The hybrid observer is not yet fully operational at this point, but it is ready to receive data.

[0043] Step S2: The hybrid observer determines the initial commutation angle based on the terminal voltage signal and the line current signal, and sends it to the adaptive controller.

[0044] After receiving the voltage and current signals in a stationary state from the sampling module, the hybrid observer initiates the initial position detection algorithm. The hybrid observer internally includes a back EMF sampling module, a current slope detection module, and an adaptive algorithm module. However, in a stationary state, the back EMF is zero; therefore, initial position detection primarily relies on the cooperation of the current slope detection module and the adaptive algorithm module.

[0045] The hybrid observer sends the determined initial commutation angle through its output to the first input of the adaptive controller.

[0046] Step S3: The adaptive controller generates a high-frequency excitation signal based on the initial commutation angle, drives the inverter to output a high-frequency rotating magnetic field, and enables the rotor to obtain initial position information.

[0047] After receiving the initial commutation angle from the hybrid observer at its first input terminal, the adaptive start-up module integrated within the adaptive controller begins operation. The adaptive start-up module generates a high-frequency rotating magnetic field excitation signal based on the initial commutation angle.

[0048] These high-frequency excitation signals are sent to the inverter's control terminal through the output of the adaptive controller. After receiving the PWM excitation signal, the inverter's control terminal uses its internal three-phase full-bridge power circuit to convert the DC bus voltage into the corresponding high-frequency AC voltage, which is then applied to the three-phase windings of the brushless motor.

[0049] A high-frequency rotating magnetic field generates a high-frequency current in the stator winding. This current interacts with the rotor permanent magnet, producing a tiny electromagnetic torque that causes the rotor to vibrate slightly or rotate at a small angle, thus "awakening" the rotor.

[0050] Step S4: The adaptive controller controls the inverter to drive the motor to rotate in an open-loop excitation mode, while the sampling module collects the terminal voltage signal and line current signal in real time and sends them to the hybrid observer.

[0051] After the rotor obtains initial position information, the adaptive start-up module switches the control mode to open-loop excitation mode. In open-loop excitation mode, the adaptive controller generates PWM control signals according to a preset voltage-frequency curve, driving the inverter to output a three-phase AC voltage with gradually increasing amplitude and frequency. The starting frequency is set to a low value (e.g., 5Hz), and the voltage amplitude starts from zero or a small value, gradually increasing at a certain slope.

[0052] Step S5: The hybrid observer, based on the real-time acquired terminal voltage signal and line current signal, outputs the real-time rotor position information to the adaptive controller and dynamic commutation compensation module by fusing back electromotive force and current slope information.

[0053] The back EMF sampling module processes the terminal voltage signal and estimates the back EMF and its rate of change based on the voltage equation of the brushless motor. During the initial open-loop startup phase, the back EMF signal is weak, and the sampling module uses low gain or filtering to extract the signal. As the speed increases, the back EMF gradually strengthens, and the estimation accuracy gradually improves.

[0054] The current slope detection module processes the line current signal and calculates the instantaneous current slope using a differential algorithm. Since the current signal contains switching noise and measurement noise, the current slope detection module first performs digital filtering on the current signal, and then uses a backward differential method to calculate the derivative of the current with respect to time to obtain the current slope information.

[0055] The adaptive algorithm module fuses the back EMF and its rate of change output from the back EMF sampling module with the current slope information output from the current slope detection module. Internally, the adaptive algorithm module employs an adaptive Kalman filter algorithm to establish state equations and observation equations that include rotor position and speed. During the fusion process, the fusion weights are dynamically adjusted according to the current speed: the current slope has a higher weight at low speeds, and the back EMF has a higher weight at high speeds.

[0056] Step S6: When the motor speed reaches the preset threshold, the adaptive controller gradually adjusts the PWM duty cycle according to the real-time rotor position information, so that the motor transitions from open-loop excitation mode to closed-loop control mode.

[0057] In open-loop excitation mode, the motor speed gradually increases. The speed information continuously output by the hybrid observer is sent to the adaptive controller. The adaptive controller has a preset speed threshold (e.g., 500 RPM) to determine whether the conditions for switching to closed-loop control are met.

[0058] When the motor speed reaches a preset threshold and the position estimation error output by the hybrid observer stabilizes within an acceptable range (e.g., confirmed by 10 consecutive samples), the adaptive controller begins executing the switching procedure. The switching process employs a soft switching method to avoid sudden torque changes.

[0059] Step S7: During the closed-loop operation phase, the dynamic commutation compensation module detects the freewheeling current of the non-conducting phase and calculates the commutation advance angle based on the line current signal collected in real time by the sampling module and the rotor real-time position information output by the hybrid observer, and outputs it to the adaptive controller.

[0060] The dynamic commutation compensation module sends the calculated commutation advance angle to the second input of the adaptive controller through its output.

[0061] Step S8: The adaptive controller generates a PWM control signal based on the real-time rotor position information and the commutation advance angle to drive the inverter to achieve precise commutation control.

[0062] The inverter precisely controls the switching of six power switching transistors based on the received PWM control signal, converting the DC bus voltage into the required three-phase AC voltage applied to the motor windings. Since the commutation timing has been compensated, freewheeling interference is effectively suppressed, the commutation process is smoother, torque ripple is significantly reduced, and precise commutation control is achieved.

[0063] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. The invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0064] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A brushless motor system, characterized in that, include Sampling module; used to acquire the terminal voltage signal and line current signal of the brushless motor in real time; Hybrid observer; It is used to sample the motor terminal voltage, line current and current slope in real time, and use an adaptive algorithm to predict the rotor position; Dynamic commutation compensation module; Used to detect motor line current and back EMF waveforms in real time, and adjust commutation angle and PWM duty cycle; Adaptive controller; responsible for signal processing, adaptive startup, and PWM generation; And inverters; Used to drive a brushless motor based on a PWM control signal.

2. The brushless motor system according to claim 1, characterized in that, The hybrid observer includes: Back EMF sampling module is used to estimate motor speed and position; The current slope detection module is used to obtain the instantaneous current slope; And an adaptive algorithm module, which is used to predict and output the real-time position information of the rotor and the commutation advance angle.

3. The brushless motor system according to claim 1, characterized in that, The adaptive controller includes an adaptive startup module for generating an open-loop high-frequency excitation signal and adjusting the PWM duty cycle.

4. The brushless motor system according to claim 1, characterized in that, The dynamic commutation compensation module monitors the change in freewheeling current of the non-conducting phase in real time during commutation. Based on the current motor load and speed status, the optimal commutation advance angle is calculated using an adaptive compensation algorithm and output to the adaptive controller.

5. A brushless motor system according to claim 1, characterized in that, The output of the sampling module is electrically connected to the hybrid observer, and the input is electrically connected to the brushless motor. The first output terminal of the hybrid observer is electrically connected to the dynamic commutation compensation module, and the second output terminal is electrically connected to the adaptive controller. The output of the dynamic commutation compensation module is electrically connected to the adaptive controller; The output of the adaptive controller is electrically connected to the inverter; The inverter is electrically connected to the input terminal of the brushless motor.

6. A brushless motor system according to claim 1, characterized in that, It also includes a fault detection module; The fault detection module includes current, voltage, and temperature sensors for monitoring current, voltage, and temperature parameters.

7. A control method for a brushless motor system, characterized in that, Includes the following steps S1. When the system is powered on, the sampling module collects the terminal voltage signal and line current signal of the motor in a stationary state and sends them to the hybrid observer. S2. The hybrid observer determines the initial commutation angle based on the terminal voltage signal and the line current signal, and sends it to the adaptive controller; S3. The adaptive controller generates a high-frequency excitation signal based on the initial commutation angle, drives the inverter to output a high-frequency rotating magnetic field, and enables the rotor to obtain initial position information. S4. The adaptive controller controls the inverter to drive the motor rotation in an open-loop excitation mode. At the same time, the sampling module collects the terminal voltage signal and line current signal in real time and sends them to the hybrid observer. S5. The hybrid observer, based on the real-time acquired terminal voltage signal and line current signal, outputs the real-time rotor position information to the adaptive controller and dynamic commutation compensation module by fusing back electromotive force and current slope information. S6. When the motor speed reaches the preset threshold, the adaptive controller gradually adjusts the PWM duty cycle according to the real-time rotor position information, so that the motor transitions from open-loop excitation mode to closed-loop control mode. S7. During the closed-loop operation phase, the dynamic commutation compensation module detects the freewheeling current of the non-conducting phase and calculates the commutation advance angle based on the line current signal collected in real time by the sampling module and the rotor real-time position information output by the hybrid observer, and outputs it to the adaptive controller. S8. The adaptive controller generates a PWM control signal based on the real-time rotor position information and the commutation advance angle to drive the inverter to achieve precise commutation control.

8. The brushless motor system control method according to claim 7, characterized in that, The process of mixing the real-time rotor position information output by the observer in step S5 includes... Acquire voltage and current signals; Filter the voltage signal and calculate the slope of the current signal; Calculate the back electromotive force and its rate of change; Output the real-time rotor position information and commutation advance angle.

9. The brushless motor system control method according to claim 7, characterized in that, It also includes step S9 The fault detection module monitors current, voltage, and temperature signals; When an anomaly is detected, the protection mechanism is triggered, and a shutdown or current limiting signal is output. After the fault is recovered, it will re-enter the closed-loop operation state.

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