A novel equivalent consumption minimization strategy for hybrid electric vehicle powered by fuel cell, battery and supercapacitor

The aim of this paper is to present a sequential quadratic programming (SQP) based equivalent consumption minimum strategy (ECMS) (SECMS) for fuel cell hybrid electric vehicle (FCHEV) powered by fuel cell, battery and supercapacitor. In order to decrease hydrogen consumption and increase the durability of power sources, fuel cell is chosen as the main power source and supplies steady current, battery is designed as the main energy buffer and the replacement of fuel cell failure and supercapacitor is operated to supply peak power. Low energy density of supercpacitor lets its equivalent hydrogen consumption be taken as zero for many ECMS researches. This simplification leads to suboptimal fuel economy and complex of control system. SECMS considers hydrogen consumption of three power sources into objective function to solve this problem. A rule based control strategy (RBCS) and an hybrid ECMS operating mode control strategy (OMCS) (HEOS) are also designed to compare with SECMS. An experimental test bench is built to validate the comparative study of three strategies. The results show that compared with RBCS and HEOS, hydrogen consumption of SECMS decreases of 2.16% and 1,47% respectively and it also has the most smooth fuel cell current, which means a lowest fuel cell degradation.