Pure Electric Vehicles Transmission Parameter Matching And Transmission Ratio Optimization Research

In order to solve pure electric vehicle’s insufficient mileage, which current pure electric vehicles are equipped with fixed speed ratio gear transmission or only two gear transmission with high speed and low speed. This paper bases on a type pure electric vehicle, adjust the gear numbers and transmission ratio, use the ADVISOR simulation software to analyze two gear to five gear pure electric vehicle’s performance. The simulation results show that five gear pure electric vehicle’s performance and economy is better than other gear number’s pure electric vehicle. Under drive motor and power battery certain conditions, genetic algorithm optimize five gear pure electric vehicle’s transmission ratio, make five gear pure electric vehicle achieve the best performance. Specific research is as follows:(1)Based on pure electric vehicle’s mechanical characteristics analysis, this paper researched pure electric vehicle’s performance requirements and main influence factors, provide reference and basis for motor and battery’s selection.(2) Through research and study drive motor and power battery’s characteristics, provide theoretical basis for pure electric vehicle transmission parameter’s match and gear number’s determining, and provide theoretical support for low-speed motor match multiple gear transmission.(3) Based on the research of motor and battery’s characteristics, this paper analyzes pure electric vehicle’s different transmission system structure, transmission system characteristics, gear number’s determination principle and transmission ratio’s determination principle.(4)Establish pure electric vehicle’s transmission components model in ADVISOR, simulate two gears to five gears pure electric vehicle’s performance and economy, and comparative analyze simulation result. According to pure electric vehicle dynamic and mileage’s requirements, optimize five gear pure electric vehicle’s transmission ratio with genetic algorithm.The simulation results show that pure electric vehicle can use low-speed motor match multiple gear transmission; traditional method that calculate transmission ratio apply to pure electric vehicle; with increasing the gear numbers, pure electric vehicle’s dynamic and economy will improve, five gear pure electric vehicle’s maximum speed can reach 120km/h and SOC=0.945. These two indicators are better than other gear numbers’ pure electric vehicle. Genetic algorithm optimization’s results show that five gear number pure electric vehicle’s acceleration performance and grade ability performance improve after optimization, and efficiency improve 12.77%.