Study on Electric Control System for a Full Hybrid Bus

For efficient and reliable operation of a novel hybrid powertrain assembled in the bus, a set of control strategy combined with the structural characteristics was researched. Based on the identification of the driver´s intension, this paper presented the logic and coordinative control method to the engine, the two motors and related accessories. One electric machine responded rapidly to comfort the power demand. And the other one was used to start&stop and to adjust the operation point of the engine with dynamic limit method. The operation of the two electric machines and the engine were optimized further to enhance the fuel economy and emission performance. Several prototypes of electric control unit were designed and tested. The performances of the hybrid electric buses are strongly improved.