Study On Control Strategy About Hybrid Electrical Vehicle Based On Parameters' Statistical Characteristics

The problem of air pollution aggravated in recent years,the law of exhaust emission also became stricter,so it's an urgent and arduous task for the automotive industry to adjust the energy-resource strcture.But due to the limitation of battery energy density,Electric-Vehicle still could not replace the status of traditional internal combustion engine vehicle.Hybrid Electric Vehicle combine the benefit of the both,lower the fuel consumption and lower the exhaust emission,and lengthen the range dramatically.The research target of this paper aims at the control strategy of middle class hybrid electric vehicle,combine the simplicity and significance of traditional control strategy based on logical threshold and the target of highest system efficiency.Used the method of statistical to compute the average speed and average power in driving situation when regenerative braking occurs,set the highest system efficiency as the calculate goal to make the backward calculation optimization way.Matched the best battery SOC under the speed and power when get the highest system efficiency,to make the highest efficiency in different driving situation,I did the work as follows;Researched the classification of different types of the hybrid electric vehicle,redid the power matching and calculate the parameters of components,choose the best matching for the research target.Calcutated the parts parameters and power matching in different point of view of extreme conditions,especially calculate the required power in different extreme conditions.Aiming at the different subconditions,re-classified the subconditions of middle class hybrid electric vehicle,treat the highest system efficiency as the optimal target,optimize the sub-conditions of engine single drive mode(the best power mode),optimize the motor single drive condition and optimize the two sub-contions of the joint drive by engine and motor(one is the engine small load charge,the other is motor assistence).Made the backward calculation for these sub-conditions,to optimize the parameters under the target of the highest system efficiency.Combined the statistical average brake velocity,average brake power and the result of backward calculation under the highest system efficiency optimization,to backward calculate the target battery SOC when brake.Treat the target SOC as control variable to adjust the control strategy in different modes,then draft the control strategy based on the statistical parameters' backward calculation.Built the simulation model of the middle class hybrid electric vehicle that equipped with CVT in the environment of Matlab/Simulink,embedded the control strategy into the simulation model to simulate in subconditions,then verified the effectiveness of control strategy and tested the reasonable meaning of simulation model.