Two-Stage and Integrated Fuel Cell Power Conditioner: Performance Comparison

Fuel cell based power supply system needs a power conditioner to convert the low dc output voltage generated by the fuel cell into usable ac voltage for any practical application. For proper power conditioning design, fuel cell electrical characteristics as well as customer requirements are taken into account. This paper presents a design methodology and performance comparison for two different power conditioner architectures recommended for using in a stand-alone power generation system with 120 Vac output voltage (sinusoidal single phase) and low input voltage (26 Vdc). Traditional two-stage power conditioner architecture which consists of an active clamp full-bridge boost converter (ACFBC) for the dc-dc stage and a full-bridge sinusoidal pulse width modulation (SPWM) inverter for dc-ac stage is presented. Besides, attempting to reduce the conversion stages (and hence reducing the total components number) a single stage power conditioner architecture which combines the ACFBC structure with the SPWM technique into an integrated architecture is also presented. In addition, a brief introduction of fuel cells and an examination of the main power conditioning requirements for residential application are included.