STEP-OUT DETECTING EQUIPMENT OF SYNCHRONOUS MOTOR, STEP- OUT DETECTING METHOD OF SYNCHRONOUS MOTOR, DRIVE EQUIPMENT OF HERMETIC COMPRESSOR AND DRIVE EQUIPMENT OF FAN MOTOR

摘要

PROBLEM TO BE SOLVED: To provide step-out detecting equipment of a synchronous motor which can detect precisely step-out of a synchronous motor by simplified step-out detecting process. SOLUTION: Inverter equipment which drives the synchronous motor without using a position sensor for detecting a rotor position is provided with a current detecting means for detecting a current flowing in the synchronous motor, a d-q coordinate transforming means for performing coordinate transformation of a current signal obtained by the current detecting means into an exciting current component (d axis current) and a torque current component (q axis current), a current AC component detecting means for obtaining AC components of the d-q axis current obtained by the d-q coordinate transforming means, and a step-out detecting means for detecting step-out by comparing at least one of d-q axis current AC components obtained by the current AC component detecting means with an arbitrarily set step-out level signal.