Abstract
In a power conditioning fuel cell system, the application of a single phase voltage source inverter (VSI) generates a second harmonic (100/120 Hz) ripple current. The harmonic current reduces life, efficiency and performance of the fuel cells due to hysteresis loss effects. This paper proposes current source inverter (CSI) with multilevel features to reduce the second harmonic (100/120 Hz) current ripple drawn from the Proton Exchange Membrane (PEM) fuel cell. The employment of energy recovery scheme in the proposed five-level multilevel current source inverter (MCSI) introduces a single switching state for each output current level. The proposed energy recovery scheme is able to balance the sharing inductor currents effectively. In addition, the proposed MCSI is also integrated with a boost DC current source in order to reduce the size of input DC link inductor and minimize the circuit structure for a reliable power conditioning PEM fuel cell system application.