| 摘要 |
PURPOSE:To reduce the capacity of a power converter by feeding back energy generated by an inductance when a semiconductor switch is turned OFF to a smoothing capacitor for a DC power source, thereby suppressing the voltage rise of a clamping capacitor. CONSTITUTION:A bridge type inverter applies a DC power obtained from 3-phase full-wave rectifiers 1 and a smoothing capacitor 3 to an inverter 4 of semiconductor switches 5-8 to convert the DC into a high frequency AC to again rectify from the secondary side of an output transformer 11, and supplies it to a load. In this case, a voltage clamping circuit made of series circuits of capacitors 15, 17, and a capacitor 16, a diode 18 are provided in parallel with semiconductor switch groups 5-8, and the connecting points (a), (b) of the cathodes of diodes 17, 18 and the capacitors 15, 16 are connected through feedback diodes 19, 20 with the high voltage side of the capacitor 3. Thus, it is fed back through diodes 19, 20 with the capacitor 3, and the switches 5-8 can be protected. |
