Control Algorithm Optimization Of Power-split HEV Based On Systematic Instantaneous Optimal

The energy crisis and environmental pollution have become one of the many themesnowadays, people are constantly looking for new energy solutions; vehicle, as a importanttransport tool of human, has spent hundreds of hours with humanity, but also brought a lot ofpressure to environment and energy. Electric vehicles are likely to become the ultimatedirection of vehicle development, but on account of the limitation in battery technology,motor technology, and price, electric vehicle still cannot be compared with conventionalvehicle. Hybrid electric vehicle (HEV), a middle form from conventional to electric vehicle,still has great value of research. Control algorithms is the core component of HEV, while thisarticle focuses on algorithm optimization based on configuration of power-split HEV.It is possible for power-split hybrid electric to achieve dual decoupling of speed andtorque between wheels and engine, so most current research on algorithm are based on theoptimal engine curve; while this algorithm can guarantee a single power source—engineinstantaneously of optimal efficiency, for the whole system composed of engine, motor, andplanet gear drive, instantaneous efficiency is not always high. At any transient state ofvehicle, there must be a point that the system is of most efficient point with the best fueleconomy. This article introduces a middle state variable, separation factor, to find theinstantaneous optimal point of system, and to develop control algorithm based oninstantaneous optimal. On this basis, research content of this paper is mainly made of a fewparts，show as:1，A configuration of power-split HEV is selected, and simulation model is built basedon mechatronics-development vehicle simulation software AMESim. Model includes engine,electric motor MG1and MG2, Powertrain and vehicle dynamics module.2，Control algorithm based on engine optimal curve is developed on SIMULINK software and co-simulation of simulink-AMESim simulation platform. Algorithms includesvehicle mode switching, torque management of individual power sources between differentmodes, energy recovery strategy, and so on.3， Based on the theory of separation factor, combined with the motor parameters, todetermine a method for determining best separation factor, and method is used to find thebest separation factor of algorithm.4，To develop control strategy based on system instantaneous optimal, in order tooptimize control algorithm based on the optimal engine curve. The algorithm is developedbased on the best separation factor table. Then do co-simulation SIMULINK-AMESim toget simulation results. Comparison between results based on the engine optimal curve andresults based on the system instantaneous optimal control algorithm and the validation basedon instantaneous optimal control algorithm mentioned effect on performance, it is validatedthat control algorithm based on system instantaneous optimal has good effect on theperformance of vehicle.