| 摘要 |
PURPOSE:To obtain an economical inverter unit having high performance by providing two DC voltage sources, inverters and output transformers, operating them in a direct coupling inverter in a low frequency range, and operating them as multiplex inverters in a high frequency range. CONSTITUTION:DC voltage sources Vd1, Vd2 connected in series are connected to a load unit LOAD through an inverter unit having inverters INV-1, INV-2, switches SW1-SW5 and output transformers TR1, TR2. If an output frequency is low, the switches SW1-SW4 are opened, and the switch SW5 is closed. That is, power is supplied directly from the inverter to the unit LOAD. If the output frequency becomes a predetermined value or higher, the switch SW5 is opened, and the switches SW1-SW4 are closed. That is, the power is supplied to the unit LOAD through the transformers TR1, TR2. |
