Research On Energy Management Strategyof The Extended-range Micro Electric Vehicle

The human social life pressure that energy and environment of the world has brought to,makes Extended-Range Electric Vehicle have become the direction of development and research of an important new energy vehicle,which has the advantages that it not just dramatically decreases the human dependency on petroleum,but effectively reduces the air pollution.By using the methods of theoretical analysis as well as computer simulation,the dissertation has studied the energy management strategy(EMS)of E-REV.The research route of this paper is as follows: firstly,power train parameters matching design of E-REV;secondly,system modeling;finally,the energy management strategy development.According to the E-REV features of which can acquire electricity from the utility grid,its battery capacity is relatively large and the engine power is relatively small,and it has pure electric/extendedrange modes,the power train system scheme of E-REV in series configuration is decided.Moreover,a novel method of E-REV power train parameters matching is proposed,and its feasibility has been verified.By the method of mixing the theoretical modeling with the experimental modeling,an E-REV feed-forward simulation model including the components and vehicle dynamics is built by AVL Cruise software.Through dynamic link library,the energy management part is built in SIMULINK and imported to the Cruise model.A new successive approximation algorithm is designed to control the engine operating points.Comparing to the traditional PID control,the proposed successive approximation algorithm has a higher control precision and a better stability.Whenever the engine has one or more operating points,the algorithm always provides satisfying control effects,for instance along its optimal curve.According to the design principle and the separation of mode layers of energy management strategy,the dissertation layouts an E-REV control strategy based on multi-modes switching.For the E-REV energy management under range-extended mode,three different controlstrategies are put forward.The reasons for fuel economy differences are analyzed from three respects:distribution of engine operating points,range extender efficiency and battery energy losses during charge-discharge process,aiming to obtain a better energy management strategy for E-REV power system.Simulation results prove that on / off control strategyfor a constrained engine is the best.