power distribution development and optimization of hybrid energy storage system

in this paper, the development and optimization of power distribution control strategy (pdcs) have been performed for a hybrid energy storage systems (hess) of a series hybrid electric bus (sheb). a common pdcs is based on the use of ultra-capacitor (uc) pack. a new simple pdcs is developed as a battery based one. for the battery based pdcs, four parameters are introduced for tuning the pdcs performance. the design of experiment (doe) method is utilized to optimize the parameters of the battery based pdcs for the driving cycles and the vehicle controllers. the results show the optimized battery based pdcs performance for some cases are better than the uc based pdcs performance. vice versa, for some cases the performance of the uc based pdcs is better than the battery based pdcs. finally, the costs rising from the hess (about 66%) is reasonable when considering the over double increase in the battery life-time when using an appropriate pdcs.