High gain multi-input DC-DC converter with combined phase-shift/PWM modulation for stand-alone applications

The existence of unreliable renewable energy resources would be required to use energy resources and storage units simultaneously, particularly in applications such as electrical vehicles and stand-alone energy supplying systems. The objective of this paper is to introduce a new topology of multi input converter in hybrid power supply system of photovoltaic, fuel cell and battery for medium power applications. In this converter, the current ripple is eliminated, due to the presence of the coupled inductor. On the other hand, the probability to achieve a high voltage efficiency, to develop a high voltage DC link, will be achieved by using two transformers, which their terminals are in series. Since a combination of the magnetizing and the leakage inductors of these two transformers are used, there will be a zero voltage switching for switches, and also a soft switching for the output diodes, because of the presence of the leakage inductor in the secondary side of transformers. Steady state model and control system is discussed for the proposed converter. A 200 watt experimental prototype has been made in laboratory to evaluate the proposed converter.