POSITION-SENSORLESS CONTROL METHOD FOR SYNCHRONOUS MOTOR, AND POSITION-SENSORLESS CONTROLLER

摘要

PROBLEM TO BE SOLVED: To provide a sensorless control method and a controller for a synchronous motor, which can materialize the smooth switchover of the angle estimation systems for low speed range and high speed range, in an estimation system which converges the error between the estimated angle of a rotor and the actual angle to zero. SOLUTION: An error for low speed by the estimation system for low speed is made, and an error for high speed by the estimation method for high speed is made, and an error after addition is made by substantially adding the error for low speed and the error for high speed at a specified rate, and the estimated error is corrected so that this error after addition may converge to zero, and the angle estimation system for low speed range or the high speed range is switched over smoothly.