POWER SUPPLY APPARATUS

摘要

A power conversion circuit connected to a three phase alternating current line is controlled in a PWM system. To control an arm corresponding to each phase, first to third carrier wave signals are generated. The first to third carrier wave signals include two signals having phases, respectively, offset by 180 degrees from each other. This allows a zero phase component to less frequently reach a peak value and be accordingly reduced as time averaged. This can reduce a zero phase harmonic component generated from a power supply apparatus.

主权项

1. A power supply apparatus comprising:
a power conversion circuit including first to third arms connected to first to third alternating current lines, respectively; a filter disposed between said first to third alternating current lines and said power conversion circuit; and a PWM control circuit for controlling said power conversion circuit in a pulse width modulation (PWM) method, said PWM control circuit including
a first voltage command value generation circuit generating first to third voltage command values corresponding to said first to third alternating current lines, respectively, in voltage,a first carrier wave signal generation circuit generating first to third carrier wave signals corresponding to said first to third voltage command values, respectively,a first comparator comparing said first voltage command value with a value of said first carrier wave signal to generate a first control signal for controlling said first arm,a second comparator comparing said second voltage command value with a value of said second carrier wave signal to generate a second control signal for controlling said second arm, anda third comparator comparing said third voltage command value with a value of said third carrier wave signal to generate a third control signal for controlling said third arm, said first to third carrier wave signals including first and second signals having phases offset by 180 degrees from each other.