Research Of Power System Model And Control Strategy On Engine-generator Set In Range-extended Electric Vehicle

The limited range problem of pure electric vehicle urges us to focus on range-extendedelectric vehicle (REEV). Because of its advantages: long driving range, simple structure,low emission, pure electric mode and so on, REEV is reasonable for city electric bus. Thispaper is based on project Key technology research and application of power system onrange-extended electric school bus. The main research of this paper is dynamic modelingfor APU and energy management strategy for the best fuel economy based on the model.The type of engine, generator, battery, and motor are selected to match the request ofpower system in the renge-extended electric school bus. Analyse the characteristics ofengine and generator based on bench test, and prepare data for modeling.Based on characteristics and parameter of every part, with Matlab/Simulink, themathematical model of range-extended electric school bus is built, in which a controllableAC/DC is added after generator. Based on physical principles, the physical model is builtfor APU, which can reflect its steady and dynanmic characteristics.For APU control, thermostat control strategy and power following control strategy aredesigned to manage energy. With Chinese urban bus operating mode, twe control structuresincluding torque control and current control for generator are simulated in above eachenergy management. Taking dynamic fuel consumption in consideration, The fuelconsumption in this two energy managements is calculated and compared, and thermostatcontrol strategy with current control structure is chosen for APU.An VCU controller is designed in this paper, it can reaceive the data of pedals andvehicle speed to read driver’s intention, monitor driving motor, transmission, engine,generator controller and so on through CAN bus. With the VCU, a series of bench tests aretaken to test its reliability.