Designing a new intelligent strategy in hybrid electric vehicles

Based on the problems caused by today conventional vehicles, much attention has been put on the fuel cell vehicles researches. However, using a fuel cell system is not adequate alone in transportation applications, because the load power profile includes transient that is not compatible with the fuel cell dynamic. To solve this problem, hybridization of the fuel cell and energy storage devices such as batteries and ultra-capacitors are usually applied. This article has studied a hybrid electric vehicle comprising a fuel cell system and ultra-capacitor bank. Energy management strategy is one of the essential issues in hybrid electric vehicles designing, in order to optimal distribution of power, improving both the fuel economy and the performance of vehicle s components. In this paper an intelligent strategy has been proposed based on load power sharing and Fuzzy logic to achieve an optimal distribution of energy between the vehicle s power sources; and, to ensure reasonable performance of the vehicle s components. For load power sharing, a Wavelet transform is useded. fuzzy logic controller is used to design the base of proposed energy management strategy. The proposed strategy is assessed in the UDDS Standard drive cycle. Simulation results show that the proposed control strategy can fulfill all the requirements of an optimal energy management

Keywords:

Hybrid Electric Vehicle , Fuzzy Logic Controller , Wavelet Transform , Fuel Cell , Ultra-capacitor