A fuel cell system with Z-source inverters and ultracapacitors

In this paper a fuel cell system with Z-source inverter and ultracapacitors for voltage sag compensation is proposed. The structure of Z-source inverter is simple. It has unique features that can boost without a DC/DC converter using only a modified switching pattern. Fuel cells have unique output characteristics. The fuel cell system can experience start-up transient and voltage sag. Simulation results show that the proposed fuel cell system with Z-source inverter and ultracapacitors is capable of operating with stable response to the system transient and voltage sags.