INVERTER CONTROL CIRCUIT AND INTERCONNECTION INVERTER SYSTEM HAVING THAT INVERTER CONTROL CIRCUIT

摘要

Provided is an inverter control circuit (6) that uses a PWM signal to control the driving of a plurality of switching means in a three-phase inverter circuit (2).  Phase voltages from the three-phase inverter circuit (2) are output via a lowpass filter (3).  The phase voltages output via the lowpass filter (3) have waveforms, which will be described below, under control of the PWM signal.  Each of the waveforms exhibits a zero value during 1/3 of its period, becomes a sinusoidal waveform varying from zero to 2p/3 in phase during the next 1/3 of its period, and also becomes a sinusoidal waveform varying from p/3 to p in phase during the remaining 1/3 of its period.  This PWM signal is adapted to have an interval in which no pulses periodically occur.  Therefore, the switching operation of the switching means is periodically halted.