摘要 |
The inverter device contains three sets of series circuit formed by connecting two switching elements (2) in series between a positive terminal and a negative terminal of DC power supply (1). Connecting points of the two switching elements are connected to motor (11). DC voltage of DC power supply (1) is switched by PWM 3-phase modulation so that a sinusoidal wave-shaped AC current is fed to the motor. Upper-arm switching elements connected to the positive terminal of the DC power supply increase or decrease an ON period equally in all phases for a carrier cycle in the PWM 3-phase modulation so as to provide two conducting period in the carrier cycle.
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