A Double Dual Boost Converter with Switching Ripple Cancellation for PEMFC Systems

This paper presents a current-based control for a proton-exchange membrane fuel cell using the so-called double dual boost topology. In particular, we introduce a discrete time controller that, in coordination with a particular selection of inductors and capacitors, minimizes the switching ripple at the input port (current ripple) and the output port (voltage ripple) of the double dual boost converter. This converter has a particular characteristic, in contrast to the classical interleaved boost topology, in the double dual boost, the phases of the converter can have different duty ratios. The freedom to choose the duty ration for each phase can be used to select the operative point in which the input current is equal to zero. However, if individual controllers are used for each branch of the converter, the equilibrium after a transient can differ from the minimum ripple operation point; the proposed scheme regulates the output voltage and, at the same time, ensures the equilibrium remains in the minimum ripple operation in steady state. In this way, the converter can mitigate the harmonic distortion on the current extracted from the proton-exchange membrane fuel cell, which is beneficial to improve the efficiency and lifetime of the cell, and on the output voltage delivered to an output direct current bus. The results of the experiment are presented to validate the principles of the proposed system.