| Extended-Range Electric Vehicle(EREV)is a kind of new energy vehicle which is equipped with an Auxiliary Power Unit(APU)on the basis of pure electric vehicle.On the one hand,it can alleviate the pressure of increasingly tense energy shortage and is beneficial to solve environmental problems.On the other hand,it prolongs the driving course significantly.APU is one of the key components of EREV and its coordination and control is extremely important.This paper,combining the international cooperation program of the Department of Technology(2010 DFB83650),takes a compact EREV as the research subject to study the control strategy and performance optimization of APU.First of all,the paper reviews the research methods and research progress at home and abroad about energy management and control strategy as well as APU coordination and control strategy of EREV.Then,three traditional control methods based on PID is proposed,namely,speed coordination control strategy,torque coordination control strategy,speed-torque coordination control strategy.In the environment of software GT-Power and Matlab/Simulink,the coordination and control simulation model of APU is established.One-dimensional flow combustion model of engine is built by theory modeling and the model of motor is constructed by experiment modeling.The control system module is realized in the software Matlab/Simulink.With effective torque and effective fuel consumption rate as the target of observation,this paper is going to explore the accuracy of this model trough benchmark test.Then,for the three kinds of traditional coordinated control devices based on PID,the study selects starting conditions,increase the power demand conditions,reduce the power demand conditions and power sinusoidal input conditions as simulation test conditions to conduct joint simulation test.The simulation results demonstrate the differences between the control performances of each controller under different operating conditions and differentcontrol parameters.Besides,the limitations of the traditional control strategy are also analyzed in detail.The results show that the same set of PID control parameters can not meet the demand of transition,thus the traditional control strategy based on PID is “inherently deficient”.According to the influence of each control parameter on the control performance,a PID control strategy based on parameter fuzzy self-tuning is designed.Through the intelligent control switch module,in the steady state conditions,traditional speed PID control is adopted to play its strong static adjustment ability and to ensure its control accuracy and steady state.In the start phase and the dynamic phrase of operating mode conversion,the fuzzy controller is used to change the control parameters in real time to meet the power conversion requirement in variable conditions.The fuzzy controller is implemented by the“fuzzy” module.The simulation results indicate that the PID controller based on parameter fuzzy self-tuning can improve the starting condition and power demand conversion condition of APU to a great extent.Furthermore,the power follow-up characteristic is good and the controller optimization effect is remarkable.Considering the “lack of power” problem when starting the engine,the ignition advance angle of engine is optimized in the level of engine bottom auxiliary control strategy.The simulation results show that the proposed ignition advance angle control strategy can optimize the performance of APU to a certain extent.Finally,the designed control strategy is tested in the basis of the rapid prototyping development control technology.The experimental results show that the APU power response is basically consistent with the simulation results,which verified the feasibility and effectiveness of the designed PID controller based on parameter fuzzy self-tuning.In the study,the designed PID controller based on parameter fuzzy self-tuning performs well and meets the control requirements.It has certain values of reference and application and plays a positive role in market application and promotion of EREV... |
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