Power Performance and Efficiency Analysis of Two Electric-Continuously Variable Transmission for Hybrid Electric Bus

This paper proposes two different electric-continuously variable transmission (EVT) configurations for a typical hybrid electric bus (HEB) during city conditions based on the Input-split Configuration with Single Planetary gearset (ICSP) which has been widely used to passenger cars. Then the power performance and efficiency of these configurations are analyzed and compared based on the lever analogy. The analysis indicates that the practical application of the Input-split Configuration with Dual Planetary gearsets (ICDP) is difficult because the efficiency in high-speed area is low and the motor speed has exceeded the reasonable range when the vehicle runs at the maximum velocity. But the ICSP equipped with a Clutch (C-ICSP) has good applicability to the HEB. Finally, the C-ICSP and the ICSP are compared through MATLAB/Simulink and Cruise co-simulation platform. Results show that the total electric path power of C-ICSP is reduced by 13% compared with ICSP, hence the fuel consumption is reduced by 6%.