Control strategies for parallel hybrid vehicles

Presents a fuzzy logic based energy management and control strategy for parallel hybrid vehicles. Using the driver commands, the state of charge of the battery, and the motor/generator speed, a set of fuzzy logic control rules has been developed, to effectively split the power between the two powerplants: electric motor and internal combustion engine. The underlying theme of the fuzzy rules is to optimize the operational efficiency of all components, considered as one system. Simulation results are used to assess the performance of the controller. A forward-looking hybrid vehicle simulation model is used to implement the control strategies. Potential fuel economy improvement has been shown by using fuzzy logic, relative to other strategies, which maximize only the efficiency of the internal combustion engine