METHOD FOR CONTROLLING THREE-PHASE BRUSHLESS DC MOTOR COMPRISING SINGLE HALL SENSOR

摘要

A method for controlling a three-phase brushless DC motor including a single hall sensor, the method including: A) measuring a deviation angle θ of a mounting position of the single hall sensor and storing; B) starting the motor: outputting six-path PWM signals by the microprocessor to control the operation of the inverter and allowing the single hall sensor to continuously and stably measure a position signal; C) obtaining a rotating angular velocity ω=360°/T in the last 360° electric angle cycle by the microprocessor; D) calculating a real-time position angle α=ωt+θ of a present 360° electric angle cycle by the microprocessor; and E) outputting the six-path PWM signals by the microprocessor to control the operation of the inverter so as to simultaneously energize the three-phase winding (U, V, and W); and switching a current direction of each winding.

主权项

1. A method for controlling a three-phase brushless DC motor, the three-phase brushless DC motor comprising:
a) a motor body, the motor body comprising: a permanent magnet rotor assembly and a stator assembly; the stator assembly comprising a stator core and a three-phase winding (U, V, and W); and b) a motor controller, the motor controller comprising: a microprocessor, an inverter, only one hall sensor, and no additional hall sensors; an output end of the inverter being connected to the three-phase winding (U, V, and W), the hall sensor sending a signal of a rotor position to the microprocessor, and allowing the microprocessor to output six-path PWM signals to control operation of the inverter; the method comprising: A) measuring a deviation angle θ of a mounting position of the hall sensor, and storing the deviation angle; B) outputting the six-path PWM signals by the microprocessor to control the operation of the inverter, whereby enabling the stator to produce a rotating magnetic field operating at a certain velocity, enabling the rotor of the motor to rotate at a certain velocity V0, and enabling the hall sensor to continuously and stably measure a position signal; C) measuring a time segment T of the hall sensor within a last 360° electric angle cycle by the microprocessor and obtaining a rotating angular velocity ω=360°/T in the last 360° electric angle cycle; D) calculating a real-time position angle α=ωt+θ of a present 360° electric angle cycle by the microprocessor, in which co represents the rotating angular velocity of the last 360° electric angle cycle and t represents a time; and E) outputting the six-path PWM signals by the microprocessor to control the operation of the inverter so as to simultaneously energize the three-phase winding (U, V, and W); and switching a current direction of each winding according to the following equations:
U=Ev×sin αV=Ev×sin(α+120°)=Ev×sin(α+240°) in which, Ev represents an average voltage of each energized phase winding; the U-phase winding is reversed at α=0° and 180° within the 360° electric angle cycle, the V-phase winding is reversed at α=60° and 240° within the 360° electric angle cycle, and the W-phase winding is reversed at α=120° and 300°.