Simulation Research On Parameters Optimization Of The Electric Vehicle Powertrain

With the development of the society and economics, the world's oil reserves are decreasing day by day. The traditional vehicles, big consumers of the oil, face the energy shortages and environmental pollution pressure. Therefore, it is necessary for vehicle industries to search low-noise, zero emission, and energy comprehensive utilization to develop themselves. Electronic vehicles (EV) have the advantages of comforts, low-noise, lower emission, simple operation and low costs, EV technology also provides a way for solving the air pollution. Therefore, to survive, most car industries are focus on the EV study.EV is a complex system engineering, and involves many courses. EV performances, such as maximum velocity, acceleration, grade ability and driving distance, are affected by power-train system parameters. Therefore, to improve vehicle performance, we must do some research on power-train system parameters optimization.Presently, power battery technology has little breakthroughs, and EV driving distance restricts the EV popularity and development. Because the power-train design parameters, such as motor power, motor speed, power-train ratios and the matching of them, obviously affect EV dynamics and driving distance. Therefore, under the same power battery conditions, the research on power-train parameters optimization has important meanings to EV driving distance increases and EV development.Based on EV technical parameters, this paper mainly did some research on EV power-train optimization and EV performance simulation. The purpose of the paper was to improve EV performance, and through power-train ratios optimization, to make the motor output working points at the high efficiency area to increase the EV driving distance. The main contents of this paper are as follows:1. Described the EV development and classification, analyzed the EV key technology, and demonstrated the purpose and signification of the paper;2. Discussed the EV power-train composition and basic layout types, and selectively analyzed the motor working characteristic, battery working characteristic, and power-train parameters affects to vehicle performance;3. Analyzed the EV dynamic characteristics and driving distance, the first part was mainly focus on evaluation of maximum velocity, acceleration and grade ability; the second part was mainly focus on computing process of EV constant velocity driving distance and driving distance in driving cycles;4. After analyzing vehicle parameter, built vehicle simulation models and vehicle dynamics computing models by MATLAB/Simulink; simulated the vehicle performance by models above, and validated model precision through comparison with ADVISOR;5. Based on EV performance requests, optimized EV power-train ratios, and compared EV performance after optimization with that of original vehicle. Through optimization, the vehicle acceleration increased by 7.39%, grade ability increased by 20%, and the driving distance improved by 7.02% in CYC_ECE_EUDC cycle.Through the research on EV power-train parameters optimization and simulation, this paper can provide valuable references to EV early design, especially in EV dynamic characteristics and driving distance promotion aspects.