CONTROL METHOD FOR PERMANET-MAGNET TYPE SYNCHRONOUS MOTOR

摘要

PROBLEM TO BE SOLVED: To start up a synchronous motor estimating the direction of a magnet without information from a position sensor. SOLUTION: The motor comprises a dq-axis determination unit that outputs a signal for amending the output of the position-computing element with an angle of only 90 deg. in the case that a current value of the direction of the d-axis position of the output of the position-computing element, which is as of a post- predetermined time of period, is found smaller than a predetermined value by applying a DC voltage to the direction of a d-axis position of the output of a position-computing element.