A 10 kW 100 kHz ZVSWAC type DC-DC converter with free-voltage AC input for telecommunication system

This paper describes about the 10 kW, 100 kHz zero voltage switching with additional capacitors (ZVSWAC) type DC-DC converter with free voltage AC input for telecommunication system. The unit consists of two types of high frequency converters-buck converter and DC-DC converter. The buck converter gets the ZVS characteristics configured by an energy recovery snubber (ERS), which gives DC 250 V/25 A selected from AC 220 V or AC 380 V. Its switch (IGBT) is switching at 20 kHz. The modified phase shifted full bridge (PS-FB) ZVS type DC-DC converter configured by two 5 kW modules makes DC 50 V/200 A (10 kW) from DC 250 V. Its switches (MOSFETs) are switching at 100 kHz. The computer simulation and experiment are performed on both units. The prototype unit is made and tested. It has over 90% power factor and 88% efficiency at full load. It has good operating characteristics. It will be applied to a rectifier unit for the telecommunication system.