A robust energy management strategy for EVs with dual input power-split transmission. (October 2018) - Wu, Jinglai
Highlights: Proposal of dual input power-split powertrain for EVs. Optimization of energy management strategy. Real-time control strategy for tracking ideal speeds to reduce energy consumption. Abstract: A novel power-split powertrain is proposed for the electric vehicles (EVs), which consists of dual propelling motor and one planetary gear set. The original motor is replaced by two downsize motor without changing the total power. The power distribution between the two downsize motors is determined by the parameters specifications of planetary gear set, which ensures the dual input powertrain has at least the same drivability performance as conventional single input powertrain. The planetary gear set is used to realize the power-split function by adjusting the gear ratio continuously to improve overall motor efficiency. The multibody dynamic model of the planetary gear set is built, considering the effect of inertia of all components. Based on the efficiency maps of the two motors, an energy management optimization model is built to minimize the consumed power of motors and transmission at each instant. The acceleration of sun gear and mechanical power of planetary gear set are constrained to avoid the large impact of transmission. A penalty factor is introduced in the objective function to realize the robust control of motor speed. Three driving cycles are used to demonstrate the improvement of energy efficiency compared to the traditional EVs with single-speed transmission.