| With the appearance of increasingly serious environment pollution and energy safety issues,the development of electric vehicle has become an international consensus.However,because the problem of energy capacity density of battery hinders the development of pure electric vehicle,the extended-range electric vehicle can solve the range anxiety well.It is of great significance to study the key technology of extended-range electric vehicle to new energy vehicle promotion and use.The paper takes the extended-range electric city bus(E-RECB)as the research object.Based on the parameter matching of vehicle,power system modeling and experimental verification,the energy management strategy research is carried out on the basis of rules and optimization.The main research contents are as follows:Firstly,the model selection and parameter matching of key components of E-RECB were proceeded.On the premise of satisfying the design requirement of the E-RECB,the model selection and parameter matching on the key components of vehicle were proceeded.The matching method of auxiliary power unit(APU)was put forward.Under the premise of determining the basic parameters of the engine,the same generator efficiency data was used.By changing the working range of generator’s speed and torque,the matching optimization between generator and engine can be achieved,and the system efficiency of the range extender can be improved as well.It provides a basis for the selection of the working point of APU and the control strategy research.Secondly,the forward simulator model of the E-RECB was established and verified by experiments.Based on the parameter matching results,the models of driving motor,APU,power battery and vehicle control unit were established in the Matlab/Simulink software.All the sub-models were connected to form the E-RECB forward simulator model.It verified the E-RECB forward simulator model experimentally by the extended-range electric driving bench.The accuracy of the model was verified by comparing the key parameters respectively,such as power consumption of the driving motor,fuel consumption and electricity generation of the APU,which lain the foundation for the subsequent energy management strategy research.Thirdly,double charge depleting-charge sustaining(CD-CS)control strategy with multiple operation point was proposed.Based on the operating characteristics of engine and battery pack,the double CD-CS control strategy with multiple operation point wasproposed,and its model was established in the Simulink/Stateflow software.It compared with thermostat control strategy,hybrid multiple working point control strategy and CD-CS control strategy.The result indicates that the double CD-CS control strategy with multiple operation point can distribute the battery pack and APU properly,the equivalent power consumption of vehicle is reduced by 0.89%,2.33% and 7.93% respectively.At the same time,it reduces the high current operating probability of battery pack,which is beneficial to extend the service life of battery pack.Finally,the adaptive particle swarm optimization-fuzzy(APSO-Fuzzy)control strategy was proposed.It took the energy consumption cost of vehicle as the optimization target,and concluded the optimal power factor and power consumption factor by APSO-Fuzzy off-line optimization,then it obtained the optimal power consumption cost of vehicle by the on-line simulation.The simulation result indicates that APSO-Fuzzy optimizes the working characteristic of APU and battery pack,takes full advantage of battery pack power and improves the vehicle comfort on the premise of guaranteeing the dynamic property of vehicle.In the comparison of Fuzzy control strategy and double CD-CS control strategy with multiple operation point,the power consumption cost of vehicle is reduced by 1.29% and 3.09%.Meanwhile,the adaptability of APSO-Fuzzy control strategy in different driving cycle was compared,and which reached the ideal control effect.In the paper,APU matching method,double CD-CS control strategy with multiple operation point and APSO-Fuzzy control strategy were proposed,which can provide the reference for the research and development on extended-range electric vehicle. |
