Single-phase direct-current brushless motor driving control system and speed regulation method
By adopting a modular control system and a three-loop control method, the problems of starting reliability, interference, speed regulation performance and switching of single-phase brushless DC motors were solved, and efficient and stable motor drive control was achieved.
Patent Information
- Application Number
- CN202510934135.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-08
- Publication Date
- 2025-10-31
AI Technical Summary
Single-phase brushless DC motors have shortcomings in starting reliability, interference during the open-loop acceleration phase, speed regulation performance during the constant speed phase, freewheeling time adjustment, and speed gear switching, leading to problems such as starting failure, vibration, electromagnetic interference, slow dynamic response, low efficiency, and unstable switching.
A modular control system is adopted, including a startup module, an open-loop acceleration module, a constant speed module, and an anomaly detection and protection module. It combines three-loop control of position loop, speed loop and current loop, and adjusts the freewheeling time through piecewise linear fitting to achieve high-reliability startup, reduced interference, fast speed regulation and smooth switching.
It improves the startup success rate, reduces interference in the open-loop acceleration phase, achieves fast and accurate speed regulation performance and smooth speed switching, and enhances the robustness of the system and the performance, power consumption and integration of the hardware implementation.
Smart Images
Figure CN120880236A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of motor drive control, and in particular to a single-phase DC brushless motor drive control system and speed regulation method. Background Technology
[0002] Single-phase brushless DC motors are widely used in small household appliances, power tools, and cooling fans due to their simple structure, low cost, and reliable operation. Their drive control technology is the core of achieving efficient and stable operation.
[0003] Currently, drive control systems for single-phase brushless DC motors generally face the following technical challenges and limitations.
[0004] Starting reliability issues: Single-phase sensorless motors have no initial torque and require specific starting strategies (such as pre-positioning and open-loop forced support) to determine the rotor's initial position. Existing methods still have shortcomings in rotor position detection accuracy, starting success rate, and anti-interference ability, which can easily lead to starting failure or vibration.
[0005] Interference issues during the open-loop acceleration phase: To accelerate the motor to near the target speed, an open-loop carrier drive method (such as applying a PWM with a fixed duty cycle) is often used. However, this drive method generates significant electromagnetic interference (EMI), affecting system stability and the normal operation of peripheral circuits, becoming a pain point in system design.
[0006] Insufficient speed regulation performance during the constant speed phase: Traditional speed control loops (such as single-speed loop PID) do not respond quickly enough to sudden load changes or speed setpoint variations, exhibiting long rise times and large overshoot. Maintaining the accuracy and stability of the motor at the target speed is affected by various factors, such as phase current phase, back EMF detection accuracy, and freewheeling control. Existing methods are not precise enough in phase calibration and dynamic management of freewheeling time, leading to large steady-state errors or speed fluctuations.
[0007] When a motor is running at a constant speed, the duration of the freewheeling time has a significant impact on efficiency, torque ripple, and noise. Existing technologies often use a fixed freewheeling time or a simple proportional relationship, failing to make precise and adaptive dynamic adjustments based on the actual speed of the motor, resulting in low efficiency or unstable operation.
[0008] When switching between different speed gears, especially when switching from high speed to low speed, existing solutions are usually not flexible and efficient enough to achieve a fast and smooth transition (avoiding sudden changes in speed or loss of synchronization).
[0009] Therefore, the industry urgently needs a drive control solution for single-phase brushless DC motors (especially 2-pole-to-4-slot type). Summary of the Invention
[0010] This invention addresses the shortcomings of the prior art by proposing a single-phase brushless DC motor drive control system and speed regulation method to achieve the following objectives:
[0011] 1. Achieve highly reliable startup;
[0012] 2. Effectively reduces interference during the open-loop acceleration phase;
[0013] 3. Provides fast, accurate, and stable speed regulation performance during the constant speed phase, with excellent dynamic response and static accuracy;
[0014] 4. The follow-through time is dynamically adjusted precisely according to the rotational speed;
[0015] 5. Enables smooth and efficient switching between different speed gears;
[0016] 6. It adopts a modular and flexibly schedulable architecture, which facilitates the implementation of high-performance, low-power, and highly integrated hardware.
[0017] The technical solution of this invention is:
[0018] A single-phase brushless DC motor drive control system includes:
[0019] The startup module initiates the system to execute motor drive commands.
[0020] Open-loop acceleration module controls the motor to accelerate in an open-loop manner to the target speed;
[0021] The constant speed module controls the motor to rotate at a constant speed.
[0022] The motor drive controller consists of a control unit on the low-voltage side and an H-bridge drive unit on the high-voltage side. It is responsible for scheduling each module to generate PWM signals to drive the motor load, and also receives feedback signals from the motor to generate corresponding actions.
[0023] The anomaly detection and protection module collects motor data in real time throughout the entire motor drive process. When an abnormal operating condition is detected, it terminates the normal control process of the system and enters a specific protection mode, thereby improving the robustness and robustness of the system.
[0024] The speed regulation method of the single-phase DC brushless motor drive control system includes the start-up stage, the open-loop acceleration stage, and the constant speed stage. Throughout the process, the abnormal detection and protection module collects the motor data information in real time. When an abnormal condition is detected, the system control flow is taken over by the protection mode. Based on the abnormality judgment, the system may either try to enter the normal control flow again or terminate the entire control directly.
[0025] Preferably, the startup phase includes the following steps:
[0026] (1) After the hardware power-on reset is completed, configure the motor control state vector table and complete the system parameter initialization;
[0027] (2) Check the motor control state vector table and determine the enable state bit of the start module. When the corresponding state bit is valid, the finite state machine of the start module will start to execute; otherwise, the process ends.
[0028] (3) When the finite state machine of the startup module exits after the rotor position is determined, it continues to check the motor control state vector table and judges the enable state bit of the open-loop acceleration module. When the corresponding state bit is valid, the finite state machine of the open-loop acceleration module starts to execute; otherwise, the process ends.
[0029] Preferably, the open-loop acceleration phase includes the following steps:
[0030] (4) During the open-loop acceleration phase, the system calculates the current speed of the motor in real time. When the speed reaches the target set value, it exits the carrier drive loop mode of the open-loop acceleration finite state machine.
[0031] (5) After exiting the open-loop acceleration finite state machine, continue to check the motor control state vector table and determine the enable state bit of the constant speed module. If the corresponding state bit is valid, then enter the constant speed stage; otherwise, the process ends.
[0032] Preferably, the constant velocity phase includes the following steps:
[0033] (6) When the motor enters the constant speed stage, it first goes through a state transition stage to complete the motor phase calibration;
[0034] (7) After the phase calibration is completed, the finite state machine of the constant speed module starts to execute. At this time, the system monitors the status of the external buttons in real time. When the interrupt signal of the motor stopping is detected, the process ends.
[0035] (8) Otherwise, the system further monitors the status of the external speed switching switch in real time. When the interruption signal of the motor shifting is detected, the motor enters the state transition stage.
[0036] (9) When no interruption signal for shifting gears is detected, the motor remains in the cyclic mode of the finite state machine of the constant speed module, and then the motor speed is adjusted by a three-loop control method of position loop, speed loop and current loop.
[0037] Preferably, the speed regulation control during the constant speed phase consists of an outer position loop, an inner current loop, and a middle speed loop.
[0038] The constant speed stage includes two processes: an initial acceleration and a later speed stabilization. The initial acceleration process uses current loop control to quickly increase the motor speed to near the target speed. Then, the speed loop PID algorithm further maintains the motor speed within a small range of the target set value. The position loop provides a calibration point for the motor phase, ensuring real-time correction of the motor speed calculation process and preventing interference caused by cumulative errors generated during long-term continuous operation of the motor.
[0039] Preferably, the single-phase brushless DC motor is a 2-pole-to-4-slot motor, comprising four switching transistors Q1, Q2, Q3, and Q4 forming an H-bridge circuit structure, wherein transistors Q1 and Q2 are the upper bridge arms, and transistors Q3 and Q4 are the lower bridge arms respectively connected to transistors Q1 and Q2; after the motor accelerates to the set speed in open-loop acceleration and enters the constant speed process, for the sensorless brushless DC motor system, from the perspective of phase current signal, the entire constant speed process is divided into excitation sub-process ①, freewheeling sub-process ②, and zero-phase current sub-process ③:
[0040] In the excitation process ①, it is defined that the phase current is positive, at which time Q1 and Q4 are turned on, and Q2 and Q3 are turned off; when the phase current is negative, Q2 and Q3 are turned on, and Q1 and Q4 are turned off.
[0041] During the freewheeling process ②, transistors Q3 and Q4 are turned on, while transistors Q1 and Q2 are turned off.
[0042] During the zero-phase current process ③, transistors Q1, Q2, Q3, and Q4 are all turned off;
[0043] During the constant speed phase, the freewheeling subprocess ② and the zero-phase current subprocess ③ are dynamically adjusted according to the motor speed. Among them, the freewheeling time of the freewheeling subprocess ② has a non-linear mathematical relationship with the motor speed, and a piecewise linear fitting method is used to achieve the purpose of dynamically adjusting the freewheeling time with the motor speed. The zero-phase current subprocess ③ is calibrated according to the actual use scenario through external sensors or the electrical properties of the motor itself, thereby achieving the requirement of dynamically adjusting the zero-phase current subprocess ③ with the motor speed. The relationship between the time of the excitation subprocess ① and the dynamic adjustment of the motor speed is determined by the position loop, speed loop and current loop.
[0044] Preferably, when the motor is switching speeds, a state transition phase is used to achieve this goal, specifically:
[0045] When switching from a lower speed to a higher speed, a relatively short state transition process is required; when switching from a higher speed to a lower speed, a relatively long state transition process is required in order to balance both inertia and active braking. When the system is in a state transition process, the tasks of this stage include reconfiguring the trigger threshold of the current loop and completing the calibration of the motor phase. All state transition processes use configurable timers to achieve logic reuse.
[0046] Preferably, different motor speeds correspond to different freewheeling times, and the relationship between speed and freewheeling time is fitted:
[0047] The motor speed r is divided into several intervals, where i represents the speed interval. The corresponding continuous streaming time is Following the piecewise linear design principle, within the speed range The relationship between the freewheeling time r and the rotational speed t can be expressed by the following formula:
[0048] ;
[0049] in, This is the scaling factor, which takes the value of a decimal in the range (0,1). In the hardware implementation, it is processed as a fixed-point number converted from a floating-point number. This is the bias value, which takes the value of an integer. Attached Figure Description
[0050] The present invention will be further described below with reference to the accompanying drawings and embodiments:
[0051] Figure 1 This is a framework diagram of a single-phase DC brushless motor drive control system.
[0052] Figure 2 This is a flowchart of a single-phase DC brushless motor drive control system.
[0053] Figure 3 The three-loop control principle of a single-phase brushless DC motor drive control system during the constant speed phase.
[0054] Figure 4 This refers to the phase current signal during the constant speed phase of a single-phase brushless DC motor drive control system.
[0055] Figure 5 The curves showing the relationship between the motor speed and freewheeling time during the constant-speed phase of the motor drive are provided. Detailed Implementation
[0056] like Figure 1As shown, the single-phase brushless DC motor drive control system of the present invention adopts a modular implementation, mainly including a motor drive controller, a start-up module, an open-loop acceleration module, a constant speed module, and an anomaly detection and protection module. The start-up module initiates the system to drive the motor; the open-loop acceleration module controls the motor to accelerate to the target speed; the constant speed module controls the motor to rotate at a constant speed; the anomaly detection and protection module collects motor data in real time throughout the entire motor drive process, and when an abnormal condition is detected, it terminates the normal control flow of the system and enters a specific protection mode. The motor drive controller consists of a low-voltage side control unit and a high-voltage side H-bridge drive unit, and is the hub of the entire system, responsible for scheduling various modules to generate PWM signals to drive the motor, and also receiving feedback signals from the motor to generate corresponding actions.
[0057] Specifically, such as Figure 2 As shown, the program flow of the motor drive control system is as follows:
[0058] (1) After the hardware power-on reset is completed, configure the motor control state vector table and complete the system parameter initialization;
[0059] (2) Check the motor control state vector table and determine the enable state bit of the start module. When the corresponding state bit is valid, the finite state machine of the start module will start to execute; otherwise, the process ends.
[0060] (3) When the finite state machine of the startup module exits after the rotor position is determined, it will continue to check the motor control state vector table and determine the enable state bit of the open-loop acceleration module. When the corresponding state bit is valid, the finite state machine of the open-loop acceleration module will start to execute; otherwise, the process ends.
[0061] (4) During the open-loop acceleration phase, the system will calculate the current speed of the motor in real time. When the speed reaches the target set value, it will exit the carrier drive loop mode of the open-loop acceleration finite state machine.
[0062] (5) After exiting the open-loop acceleration finite state machine, continue to check the motor control state vector table and determine the enable state bit of the constant speed module. If the corresponding state bit is valid, then enter the constant speed stage; otherwise, the process ends.
[0063] (6) When the motor enters the constant speed stage, it will first go through a state transition stage to complete the motor phase calibration;
[0064] (7) After the phase calibration is completed, the finite state machine of the constant speed module starts to execute. At this time, the system will monitor the status of the external buttons in real time. When the interrupt signal of the motor stopping is detected, the process ends.
[0065] (8) Otherwise, the system will further monitor the status of the external speed switching switch in real time. When the interruption signal of motor shifting is detected, the motor enters the state transition stage.
[0066] (9) When no interruption signal for shifting is detected, the motor remains in the cyclic mode of the finite state machine of the constant speed module, and then the motor speed is adjusted by a three-loop control method of position loop, speed loop and current loop.
[0067] (10) Throughout the process, the anomaly detection and protection module will collect the motor data information in real time. When an anomaly is detected, the system control flow will be taken over by the protection mode. Based on the anomaly judgment, it will either try to enter the normal control flow again or directly end the entire control.
[0068] like Figure 3 As shown, the speed regulation control during the constant speed phase of the motor consists of an outer position loop, an inner current loop, and a middle speed loop. The constant speed phase includes two processes: an initial continuous acceleration and a later stable speed maintenance. This method employs a two-step strategy. During the speed ramp-up process, the current loop control rapidly increases the motor speed to near the target speed. Then, the speed loop PID algorithm further maintains the motor speed within a small range of the target setpoint. The position loop provides a calibration point for the motor phase, ensuring real-time correction during motor speed calculation and preventing interference caused by accumulated errors during long-term continuous motor operation. From the perspective of important performance parameters such as rise time, overshoot, settling time, and static error, this method has significant advantages.
[0069] This speed control method is based on a 2-pole-to-4-slot single-phase brushless DC motor. After the motor accelerates in an open-loop manner to reach the set speed and enters a constant speed process, as... Figure 4 As shown, for a sensorless brushless DC motor system, the entire uniform speed process can be divided into three sub-processes based on the phase current signal: excitation sub-process ①, freewheeling sub-process ②, and zero-phase-current sub-process ③. In excitation sub-process ①, when the phase current is positive (arbitrarily defined), transistors Q1 and Q4 (including MOSFETs and IGBTs) are turned on, while transistors Q2 and Q3 are turned off; when the phase current is negative, transistors Q2 and Q3 are turned on, while transistors Q1 and Q4 are turned off. In freewheeling sub-process ②, transistors Q3 and Q4 are turned on, while transistors Q1 and Q2 are turned off. In zero-phase-current sub-process ③, transistors Q1, Q2, Q3, and Q4 are all turned off.
[0070] The main purpose of this method, which requires the motor to continuously accelerate during the initial stage of the constant speed phase, is to reduce the speed-up requirements of the open-loop acceleration module. Typically, using carrier-driven acceleration in the open-loop module causes significant signal interference. Therefore, this method only needs to accelerate the motor to an appropriate speed in the open-loop acceleration phase, and then, in conjunction with the constant speed phase, a speed adjustment strategy can further rapidly increase the motor speed. During the constant speed phase, the freewheeling sub-process ② and the zero-phase current sub-process ③ need to be dynamically adjusted according to the motor speed. The freewheeling time of the freewheeling sub-process ② has a non-linear mathematical relationship with the motor speed. Considering hardware implementation, this method uses piecewise linear fitting to achieve the goal of dynamically adjusting the freewheeling time according to the motor speed. The zero-phase current sub-process ③, depending on the actual application scenario, can be calibrated using external sensors or the motor's own electrical properties, thus achieving the requirement for dynamic adjustment of the zero-phase current sub-process ③ according to the motor speed. The relationship between the time of the excitation sub-process ① and the dynamic adjustment of the motor speed is jointly determined by the position loop, speed loop, and current loop.
[0071] When the motor switches speeds, this speed control method uses a state transition phase to achieve this goal. Essentially, it's a configurable timer that can accommodate switching requirements between different speeds. Specifically, a shorter state transition process is needed when switching from a lower speed to a higher speed; a longer process is required when switching from a higher speed to a lower speed to accommodate both inertia and active braking. During the state transition, this phase involves reconfiguring the current loop trigger threshold and calibrating the motor phase. All state transitions utilize a configurable timer for logic reuse, resulting in simple, flexible, and efficient control.
[0072] Different motor speeds (i.e., half an electrical cycle) correspond to different freewheeling times, therefore, it is necessary to fit the relationship between speed and freewheeling time. Both parameters are mathematically measured in system clock cycles, sharing the same properties and comparable magnitude, thus eliminating the need for complex preprocessing operations such as data normalization. Furthermore, experimental data on speed and freewheeling time can be easily obtained using an oscilloscope. Specifically, piecewise speed fitting can employ non-uniform interval division based on actual conditions to improve the accuracy of motor speed control. For example... Figure 5 As shown, the motor speed r is divided into several intervals, where i represents the speed interval. The corresponding continuous streaming time is Following the piecewise linear design principle, within the speed range... The relationship between the freewheeling time r and the rotational speed t can be expressed by the following formula.
[0073] ;
[0074] in, This is the scaling factor, which takes the value of a decimal in the range (0,1). In the hardware implementation, it is processed as a fixed-point number converted from a floating-point number. This is the bias value, which takes the value of an integer.
[0075] The above method provides a general design idea for the uniform speed regulation control of motors. Similarly, it is also applicable to high-order nonlinear fitting methods. In the hardware circuit implementation, the same effect can be achieved by using a lookup table instead of the piecewise linear method.
[0076] This invention provides a complete system solution for a 2-pole-to-4-slot single-phase brushless DC motor, including hardware circuit design and software scheduling strategies. Speed control of motors in constant-speed mode has always been a hot research area. This method is based on a three-loop control system (position loop, speed loop, and current loop), employing a strategy of coarse adjustment of the current loop combined with fine adjustment of the speed loop. It dynamically adjusts the freewheeling time by fitting the speed to the freewheeling time, providing a novel solution for motor speed control. This method is simple, efficient, and hardware-friendly. The modular design offers high control scheduling flexibility and good scalability. ASIC-customized hardware implementation has significant advantages in performance, power consumption, real-time performance, and integration.
[0077] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All modifications made according to the spirit and essence of the main technical solution of the present invention should be covered within the scope of protection of the present invention.
Claims
1. A single-phase DC brushless motor drive control system, characterized in that, include: The startup module initiates the system to execute motor drive commands. Open-loop acceleration module controls the motor to accelerate in an open-loop manner to the target speed; The constant speed module controls the motor to rotate at a constant speed. The motor drive controller consists of a control unit on the low-voltage side and an H-bridge drive unit on the high-voltage side. It is responsible for scheduling each module to generate PWM signals to drive the motor load, and also receives feedback signals from the motor to generate corresponding actions. The anomaly detection and protection module collects motor data in real time throughout the entire motor drive process. When an abnormal operating condition is detected, it terminates the normal control process of the system and enters a specific protection mode, thereby improving the robustness and robustness of the system.
2. A speed regulation method for a single-phase DC brushless motor drive control system, characterized in that, The system includes a startup phase, an open-loop acceleration phase, and a constant speed phase. Throughout the process, the anomaly detection and protection module collects motor data in real time. When an abnormal condition is detected, the system control flow is taken over by the protection mode. Based on the anomaly judgment, the system may either attempt to re-enter the normal control flow or terminate the entire control process directly.
3. The speed regulation method of the single-phase DC brushless motor drive control system according to claim 2, characterized in that, The startup phase includes the following steps: (1) After the hardware power-on reset is completed, configure the motor control state vector table and complete the system parameter initialization; (2) Check the motor control state vector table and determine the enable state bit of the start module. When the corresponding state bit is valid, the finite state machine of the start module will start to execute; otherwise, the process ends. (3) When the finite state machine of the startup module exits after the rotor position is determined, it continues to check the motor control state vector table and judges the enable state bit of the open-loop acceleration module. When the corresponding state bit is valid, the finite state machine of the open-loop acceleration module starts to execute; otherwise, the process ends.
4. The speed regulation method of the single-phase DC brushless motor drive control system according to claim 2, characterized in that, The open-loop acceleration phase includes the following steps: (4) During the open-loop acceleration phase, the system calculates the current speed of the motor in real time. When the speed reaches the target set value, it exits the carrier drive loop mode of the open-loop acceleration finite state machine. (5) After exiting the open-loop acceleration finite state machine, continue to check the motor control state vector table and determine the enable state bit of the constant speed module. If the corresponding state bit is valid, then enter the constant speed stage; otherwise, the process ends.
5. The speed regulation method of the single-phase DC brushless motor drive control system according to claim 2, characterized in that, The constant velocity phase includes the following steps: (6) When the motor enters the constant speed stage, it first goes through a state transition stage to complete the motor phase calibration; (7) After the phase calibration is completed, the finite state machine of the constant speed module starts to execute. At this time, the system monitors the status of the external buttons in real time. When the interrupt signal of the motor stopping is detected, the process ends. (8) Otherwise, the system further monitors the status of the external speed switching switch in real time. When the interruption signal of the motor shifting is detected, the motor enters the state transition stage. (9) When no interruption signal for shifting gears is detected, the motor remains in the cyclic mode of the finite state machine of the constant speed module, and then the motor speed is adjusted by a three-loop control method of position loop, speed loop and current loop.
6. The speed regulation method of the single-phase brushless DC motor drive control system according to claim 5, characterized in that, During the constant speed phase, the speed regulation control consists of an outer position loop, an inner current loop, and a middle speed loop. The constant speed stage includes two processes: an initial acceleration and a later speed stabilization. In the initial acceleration process, the current loop control quickly increases the motor speed to near the target speed. Then, the speed loop PID algorithm further maintains the motor speed within a small range of the target set value. The position loop provides a calibration point for the motor phase, ensuring real-time correction of the motor speed calculation process and preventing interference caused by cumulative errors generated during long-term continuous operation of the motor.
7. The speed regulation method of the single-phase DC brushless motor drive control system according to claim 6, characterized in that, The single-phase brushless DC motor is a 2-pole-to-4-slot motor, comprising four switching transistors Q1, Q2, Q3, and Q4 forming an H-bridge circuit structure. Q1 and Q2 form the upper bridge arm, and Q3 and Q4 form the lower bridge arm, respectively connected to Q1 and Q2. After the motor accelerates to the set speed and enters a constant speed process in open-loop acceleration, for a sensorless brushless DC motor system, the entire constant speed process can be divided into an excitation sub-process ①, a freewheeling sub-process ②, and a zero-phase current sub-process ③, based on the phase current signal. In the excitation process ①, it is defined that the phase current is positive, at which time Q1 and Q4 are turned on, and Q2 and Q3 are turned off; when the phase current is negative, Q2 and Q3 are turned on, and Q1 and Q4 are turned off. During the freewheeling process ②, transistors Q3 and Q4 are turned on, while transistors Q1 and Q2 are turned off. During the zero-phase current process ③, transistors Q1, Q2, Q3, and Q4 are all turned off; During the constant speed phase, the freewheeling subprocess ② and the zero-phase current subprocess ③ are dynamically adjusted according to the motor speed. Among them, the freewheeling time of the freewheeling subprocess ② has a non-linear mathematical relationship with the motor speed, and a piecewise linear fitting method is used to achieve the purpose of dynamically adjusting the freewheeling time with the motor speed. The zero-phase current subprocess ③ is calibrated according to the actual use scenario through external sensors or the electrical properties of the motor itself, thereby achieving the requirement of dynamically adjusting the zero-phase current subprocess ③ with the motor speed. The relationship between the time of the excitation subprocess ① and the dynamic adjustment of the motor speed is determined by the position loop, speed loop and current loop.
8. The speed regulation method of the single-phase DC brushless motor drive control system according to claim 7, characterized in that, When the motor is switching speeds, a state transition phase is used to achieve this goal, specifically: When switching from a lower speed to a higher speed, a relatively short state transition process is required; when switching from a higher speed to a lower speed, a relatively long state transition process is required in order to balance both inertia and active braking. When the system is in a state transition process, the tasks of this stage include reconfiguring the trigger threshold of the current loop and completing the calibration of the motor phase. All state transition processes use configurable timers to achieve logic reuse.
9. The speed regulation method of the single-phase DC brushless motor drive control system according to claim 8, characterized in that, The motor's different speeds correspond to different freewheeling times. The relationship between speed and freewheeling time is fitted: The motor speed r is divided into several intervals, where i represents the speed interval. The corresponding continuous streaming time is Following the piecewise linear design principle, within the speed range... The relationship between the freewheeling time r and the rotational speed t can be expressed by the following formula: ； in, This is the scaling factor, which takes the value of a decimal in the range (0,1). In the hardware implementation, it is processed as a fixed-point number converted from a floating-point number. This is the bias value, which takes the value of an integer.