SENSORLESS CONTROLLER FOR BRUSHLESS MOTOR

摘要

PROBLEM TO BE SOLVED: To provide a sensorless controller for a brushless motor, in which an inexpensive CPU is used, and operation processing program is not required to be changed.

SOLUTION: The sensorless controller 3 for the brushless motor 1 includes a speed calculating portion 38 to calculate a speed ω of a rotor, an angle calculating portion 37 to calculate an angle θ of the rotor at a predetermined time interval, and an angle control portion 36 to control the angle θ of the rotor by calculating a correction angle Δθ based on a current value of a d-axis current (the d-axis current value id). The angle calculating portion 37 calculates the angle θ of the rotor at the predetermined time interval, using the correction angle Δθ calculated by the angle control portion 36, the speed ω calculated by the speed calculating portion 38, predetermined time, and the angle θ of the rotor calculated by the angle calculating portion 37 at a predetermined point of time. The angle θ of the rotor thus calculated by the angle calculating portion 37 is caused to converge on a true angle of the rotor.

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