MOTOR CONTROLLER, POWER CONVERTER, AND HYBRID VEHICLE

摘要

PROBLEM TO BE SOLVED: To achieve stable motor drive through sensorless control even at the start or low-load drive of a brushless motor.

SOLUTION: A motor controller includes a voltage detecting circuit which detects an induced voltage at each phase of a motor by an analog signal and converts the result of detection into a digital signal, a PWM control circuit which carries out variable-speed control over the motor by adjusting a duty factor representing an on-time in a switching cycle of a switching element based on information of an induced voltage at a switching-off phase detected by the voltage detecting circuit, and a duty factor changing unit which changes a duty factor of the PWM control circuit based on a difference between a duty factor adjusted by the PWM control circuit and a predetermined duty factor. The PWM control circuit reads in a detection result from the voltage detecting circuit during an on-cycle of the switching element that is defined by a duty factor changed by the duty factor changing unit.

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