Researches On Power Matching And Control Strategy For Pull-type Range-extender

New energy vehicle is an effective approach to solve the severe energy and environment problem faced by automotive industry.EREV,which combine the advantages of traditional vehicles and pure electric vehicles,is currently feasible to solve the energy and environment problem.In this paper,based on the disadvantages of current extenders and model-separating method,design a pull-type range extender and make design program through the system matching,the engine improvement and the optimization of control strategy.First,design the overall objective of pull-type range extender according to the needs of current electric vehicles,and the detailed design scheme was determined including the power,economy,the whole structure and control system.Second,improved design the selected engine based on simulation model,according to the characteristics of Atkinson cycle engine,the original engine compression ratio and valve phase were simulated and optimized to improve the fuel economy.At the same time,according to the optimized Atkinson cycle engine parameters,the optimal operating point of the engine was determined.Third,determine the work mode,and the stop-start,power output and starting process control strategy was proposed according to the power,energy,cost and the complexity of the control system.And the control strategy was optimized to determine the optimal control parameters by the simulation model.Then,the control strategy was executed by control unit.At last,accomplish the design schemeby building the test benc,and verifying of basic functions of control system and control strategy of extender by Offline test and the communication and electrical connection between the extender and electric vehicles by experiment and the experiments show that the scheme has good feasibility.