COMPARATIVE STUDY OF SOFT SWITCHING METHODS USED IN DC-DC CONVERTERS

High frequency switched-mode DC-DC converters are widely used in industry such as battery charging, renewable energy, fuel-cell, power factor correction, LED lighting applications,  due to their low response time, easy controlling and high power density. However, at high switching frequency, switching losses, electromagnetic interference (EMI) and lower efficiency become substantial problem. These problems must be eliminated or reduced by using additional passive and active snubber cells in order to operate the converter with soft switching (SS) instead of hard switching (HS). In this paper, properties of soft switching methods named as zero voltage transition (ZVT), zero current transition (ZCT), and zero voltage zero current transition (ZVZCT) developed by combining the ZVT and ZCT, zero voltage switching (ZVS) and zero current switching (ZCS) are studied and discussed, simulations of soft switching DC to DC boost converters including these methods are accomplished for 500W and 1kW power at switching frequency of 100 kHz