Simulation Research On Transmission Control System Of Electric Vehicles

From the birth until now, internal combustion engine vehicle has a history of more thana hundred years, and now it’s an indispensable part of people’s life. But because the energyand environmental problems are getting increasingly serious, electric vehicle with itsenergy-saving and environmental protection features has become the research hot spot.Because the transmission and control system directly decides the driving performance, it hasbecome the priority among priorities. This paper takes BK6122EV2,11.8/22-32electric bus as the prototype to study thetransmission and control system. The transmission and control system of electric vehiclesincludes drive motor and its control system, composite power and its control system, controlsystem of brake and super capacitor energy management etc. Firstly, according to electricvehicle’s characteristics of frequent start and brake, and its existing problem of short mileage,selected the type of driving motor, batteries and other components, matched the parametersfor each component. Then, analyzed and researched on the selected driving motor, designedcontrol strategies for the driving motor in different conditions. After that, made a research ondifferent topological structures of combined power which consists of battery and supercapacitor, analyzed the method of super capacitor charging and discharging, and designedthe energy management of super capacitor according to the conditions of typical bus road.Then, analyzed the stress of the bus braking process.Based on the brake torque fixed ratiodistribution, considered the ECE brake law and road conditions, designed the fitable braketorque distribution for electric bus. Finally, built the electric bus simulation model andtransmission control system model in simulation software cruise and matlab, solving the subcontrol system switching problem in matlab model and the problem of connection betweentwo simulation software. Committed three kinds of typical circular road test to prove thevalidity of the simulation model. The results proved the parameters of each component andthe control systems can comply with the power request of city bus under typical roadconditions. By using the successfully built simulation model to study the capacity of supercapacitor to make a full use of the capacity of super capacitor.