CONTROL SYSTEM OF PWM INVERTER

摘要

PURPOSE:To prevent an output voltage generated by an ON delay of a PWM signal from varying by controlling the phase of a basic wave output voltage in a zone to become ON in response to the operating state of a load. CONSTITUTION:A PWM controller 21 outputs a PWM command signal by a voltage command and a frequency command. The output signal of the controller 21 is applied as a base current command to the transistor of a PWM inverter through an ON delay unit 23. The PWM inverter becomes ON twice during pi/3 zone, and the phase for the basic output voltage of the zone to become ON varies in response to the frequency of a load.