Research on Fuzzy Logic Control Strategy for a Plug-in Hybrid Electric City Public Bus

This paper presents a fuzzy logic torque control strategy for a plug-in parallel hybrid electric city public bus which is one type of plug-in hybrid electric vehicles (PHEVs). The control strategy design objective of the PHEV is fuel economy. Based on the Qingdao city public bus driving cycle, parameters of the electric motor, engine and battery are designed. According to the operating modes of charge-depleting (CD) and charge-sustaining (CS), the fuzzy logic control strategy is developed. Through the course of Qingdao city bus driving cycles, the simulation of the fuzzy logic control strategy is finished. Simulation results show many merits of the control strategy. Through the course of nineteen times´ Qingdao city bus driving cycles, the fuel consumption is reduced by 30%-35% compared with traditional city bus in the charge-sustaining (CS) operating mode, the maximum driving distance of the plug-in city bus based on fuzzy logic control strategy is 65 km which is longer than that (61 km) of plug-in city bus based on the logic threshold control strategy in the charge-depleting (CD) mode.