A MULTIPLE-SWITCH HIGH-VOLTAGE DC-DC CONVERTER

Series connection of power devices has evolved into a mature technique and is widely applied in RV de systems, Static and dynamic voltage ba lance is ensured by shunting individual devices with dissipative snubb ers, The snubber losses become pronounced for increased operating freq uencies and adversely affect power density, Capacitive snubbers do not exhibit these disadvantages, but they require a zero-voltage switchin g mode, Super-resonant power converters facilitate the principle of ze ro-voltage switching. A high-voltage de-de power converter with multip le series-connected devices is proposed, It allows the application of nondissipating snubbers to assist the voltage sharing between the mult iple series-connected devices and lowers turn-off losses, Simulation r esults obtained with a circuit simulator are validated in an experimen tal converter operating with two series-connected devices, The behavio r of the series connection is examined for MOSFET's and insulated gate bipolar transistors (IGBT's) by both experimental work with a 2-kW pr ototype and computer simulation, Applications can be found in traction and heavy industry, where the soft-switching converter is directly po wered from a high-voltage source.