| 摘要 |
PURPOSE:To reduce the loss of a power converting device which includes a PWM self-excited inverter connected to a system. CONSTITUTION:A power voltage disturbance detecting circuit 15 is used to detect the voltage disturbance of an AC power supply 1 in addition to a carrier frequency varying circuit 19 which varies the PWM control carrier frequency of a PWM self-excited inverter 4 connected to the power supply 1. The carrier frequency of the inverter 4 is usually kept at a low level and then set at a high level when the power supply 1 has the voltage disturbance. Thus the inverter 4 is usually operated with reduction of the switching loss. |
