Power-split characteristic analysis and comprehensive efficiency optimization for power distribution of the two-mode EVT

摘要

Electro-mechanical Variable Transmission (EVT) system can enhance the fuel economy by adjusting the engine operating points, and take full advantage of the high efficiency of the mechanical transmission. So it is a good solution for applying the hybrid electrical driving to heavy vehicles. In this paper the power-split characteristics is analyzed aiming at a special scheme of two-mode EVT and the transmission efficiency are researched. Based on the power-split characteristic and the analysis of the power component efficiency, the identification method of comprehensive efficiency is proposed. The dynamic efficiency model of the power-coupled machine is discussed in emphases. The comprehensive optimization model for power distribution is established for enhancing the system transmission efficiency. The optimization calculation and implement are carried on by system simulation, and the test results indicate that the comprehensive efficiency optimization method can control the operating points of the power components at the comprehensive optimal states, and the system transmission efficiency and the fuel economy are enhanced observably. The research of the power-split characteristic analysis and the comprehensive efficiency optimization provides foundation for developing the control strategy and control system of EVT.