Energy Management Strategy Optimization for the Electro-Mechanical Transmission System Based on PMP

The Electro-Mechanical Transmission (EMT) is a form of Heavy-Duty Vehicles Electrification. It makes use of two motor-generator units to electrically impose a continuously variable ratio between the input shaft and the transmission output shaft, thereby allowing the engine to work in a more efficient manner without respect to the vehicle speed. To realize that, the EMT system requires an algorithm controls the power split between the internal combustion engine and the electric machines. Based on Pontryagin's Minimum Principle (PMP), the optimal control theory is applied to derive a methodology for a real-time power split algorithm. To validate the performance of the proposed control strategy, a forward model is built based on Matlab/Simulink for the simulation. The simulation results show that the research of EMT control strategy has significant oil-saving effect, optimization method and the control strategy is effective.