Swinging Bus Technique for Ripple Current Elimination in Fuel Cell Power Conversion

A swinging bus scheme is investigated in this paper to eliminate undesirable low-frequency ripple current reflection in fuel cells. The swinging bus is thoroughly characterized under various loading conditions to establish a behavioral model. As a result, a general control scheme and signal processing for buck- and boost-derived power converters are obtained. A digital filter in the form of a moving averaging filter proves to be a fundamental component of the control loop, a significant practical advancement in control for low-frequency ripple elimination. A formal mathematical demonstration is included and experimental results are presented to validate the technique and illustrate its benefits.