A Low-speed Off-road Electric Vehicle Research Program By Regenerative Braking Technology

One of the effective ways to solve the resource crisis and environmental pollution around the world is the use of renewable energy or developing electric vehicles. Before the battery technology has made a revolutionary breakthrough, range extended electric vehicle is an effective measure to improve the mileage of pure electric vehicles, and using regenerative braking technology in electric vehicle can further improve the performance of electric vehicle, so regenerative braking has get more and more research and application.The object of this paper is a kind of off-road low speed range extended electric vehicle, the maximum speed is40km/h, and the cruising speed is20km/h. It’s mainly drives in various venues. On the basis of the previous work of the research group, and on the premise of low cost, the purpose of the study is improving and optimizing the performance of electric vehicles. The main work focuses on the study of regenerative braking technology of this kind of electric vehicle.The scheme of a kind of off-road low speed range extended electric vehicle is studied, and its operating principle is analyzed, the selection and the main technical parameters of main components of the power-driven system is determined, and the models of the vehicle and its main parts are built in ADVISOR, the dynamic performance and economic performance is simulated and analyzed.According to characteristics of the electric vehicle, the requirement of low cost, frequent start and stop, the speed and braking intensity is relatively lower and the ground pavement conditions are relatively better, etc. This paper has studied a regenerative braking preferred braking scheme, that’s when the motor braking force can meet the requirements of braking force, all the braking force is provided by the regenerative braking force of the motor; when the motor braking force can’t meet the braking force, then the mechanical braking force is used as a supplement, and the driving wheels only provide regeneration braking force, can’t provide mechanical braking force. And this paper also uses a simple and feasible estimation method to real-time estimation of lead-acid battery State of Charge (SOC)Simulation was done for the regenerative braking preferred braking control strategy, results show that using the control strategy of regenerative braking preferred, the braking energy recovery rate can reach36.8%in typical low-speed city conditions. Compared with the non regenerative braking, regenerative braking preferred braking control strategy can make the driving range of electric vehicles increased by12.9%.