POWER CONVERSION DEVICE

摘要

Unlike diodes, MOS-FETs are characterized by sending current flowing bidirectionally, and thus, MOS-FETs must be controlled to switch on and off with respect to the direction of the supply of electricity. A control method that is applied when using MOS-FETs in rectifier circuits cannot be used, however, when applying MOS-FETs used in rectifier circuits to develop active converters. Another problem arises with the characteristics of circuit elements when the switching frequency is greater than one in a half-period of the power supply voltage of a booster chopper circuit. The purpose of the present invention is achieved by employing super junction structure N-channel MOS-FETs comprising low-on resistance characteristics in the switching elements thereof, wherein the control means controls so as to switch all MOS-FETs on when the AC power supply and the reactor short-circuit and to switch off the MOS-FETs that are connected on the positive terminal side of the AC power supply when short-circuiting the AC power supply and the reactor is not necessary.