| 摘要 |
PURPOSE:To provide good output voltage waveform all over the output frequency range without a saturation in a transformer for inverter output at a lower frequency range with the series combination of a non-insulated inverter and an insulated inverter at the AC circuit side. CONSTITUTION:A non-insulated inverter 1 and an insulated inverter 2 are connected in series with each other on the AC circuit side. When the frequency of the output is low, the primary side of a transformer 7 of the inverter 1 is shorted through an inverter arm to allow the inverter to provide an output. When the frequency of the output is higher, the inverters 1 and 2 provide an output in cooperation with each other for multiple operation. With such an arrangement, even when the characteristics for raising E/f (E: inverter AC voltage, f: frequency) is needed at a lower frequency range, any combined multiplication can be performed without a core saturation and drop in the efficiency of the inverter. |
