| 摘要 |
PROBLEM TO BE SOLVED: To provide a voltage doubling system inverter which can operate stably under any load condition, and is suitable especially for an induction furnace where a frequency suddenly drops abnormally during thermal fusion. SOLUTION: A voltage doubling inverter device comprise a first capacitor 71 connected in parallel with first and second output terminals of a thyristor inverter 11, a second capacitor 72 connected in series to the first and second output terminals, and an induction load coil 8 connected in series between one end of the second capacitor and the second output terminal. A first gate signal generator 22 generates a gate signal for the thyristor or receiving the input of an inverter output voltage signal V1. A second gate signal generator 23 generates a gate signal for the thyristor on receiving the input of an inductive load voltage signal V2. A selection circuit 24 selects a gate signal on the side where a frequency is higher between outputs of those two first and second gate signal generators 22 and 23, or outputs a gate signal of one of outputs to the thyristor. |
