| 摘要 |
PURPOSE:To protect an inverter against breakdown and to suppress fluctuation of output voltage of the inverter unit. CONSTITUTION:Synchronism between an inverter unit INV and a bypass power supply BYP is detected at a PLL control section which then provides an output signal to the third input of a first AND circuit AND1. The first AND circuit AND1 has first and second inputs receiving, respectively, an opening signal and switching signal for a second electromagnetic switch 83I and when AND conditions are satisfied, the second electromagnetic switch 83I is closed. Consequently, a load is fed with an output current from the inverter unit. The output current and the output from the first AND circuit AND1 satisfy the AND conditions of a second AND circuit AND2 and turns a semiconductor control switch TS OFF. |
