SENSORLESS POSITION CONTROLLER OF PERMANENT MAGNET SYNCHRONOUS MOTOR

摘要

PROBLEM TO BE SOLVED: To obtain a sensorless position controller of a permanent magnet synchronous motor in which the motor can be started smoothly even if it is rotating at the time of starting. SOLUTION: The controller employing a bootstrap type charge pump comprises a charge control means for controlling conduction of a lower switching element such that it is charged when the phase current is low but not charged when the phase current is high, and means for selecting one of a plurality of starting means based on the phase current wherein a brush motor can be started smoothly even if the rotor is rotating at the time of starting.