Hybrid Proton Exchange Membrane Fuel Cell/Lithium-ion Battery System Power Management Strategy Design for Lifetime Extending of the Main Power Source

Abstract

Proton exchange membrane fuel cell (PEMFC) is regarded as one of the most promising power solutions for driving electric vehicle (EV) depending on its high efficiency, high energy density, low operation temperature, as well as zero emission. The limitations of wide application and commercialization of PEMFC in EV are low power density, unidirectional energy flow that cannot meet EV transient operating condition as well as store regenerating energy. Moreover, the transient load of EV may cause PEMFC lifetime dramatically degrade. Lithium-ion battery (LIB) is considered used in this study to hybridize with PEMFC to supply transient power demand as well as to save extra energy. To distribute power and to extend PEMFC lifetime, power management strategy based on the PEMFC operation point fixing is designed and implemented. The proposed hybrid PEMFC/LIB power system comprised by PEMFC, LIB, boost converter as well as bidirectional converter is modeled in Matlab/Simulink. Subsequently, the coordinated current-voltage control and cascade current-voltage control power splitting methods are developed to regulate DC bus voltage and PEMFC stack current. The fixed PEMFC stack current can lead to PEMFC operate in a suitable condition even the external load variations. The simulation and experimental results demonstrate that the designed power management strategy can balance the load demand and protect PEMFC.