Research On Control Study On Braking-energy Recovery System Based On Electric Vehicle

The development of automobiles faces many problems such as energy crisis,environmental pollution and noise, etc. Electric automobile is a feasible way to solve theseproblems, because it uses electricity instead of oil, and it has no exhaust emissions orpollution. Besides, such energy can be obtained through various ways, like by hydro, windand solar. At present, a lot of research has been done on electric automobiles, but there arestill limits, such as shortage of distance and lack of storage capacity. Increasing energyreservation and utilization is an effective way to solve the problem.The strategy is about how to distribute electric motor regenerative braking forceand traditional friction braking force. Both braking efficiency and driver’s feeling areensured. Now there are three control strategies: ideal braking, best braking energy recovery,parallel braking energy recovery. Considering the current technology and cost, parallelbraking energy recovery strategy was chosen for this study. Following aspects wereanalyzed in this paper to meet the ECE Regulations over optimal control strategy andelectric vehicle’s braking control strategy: subject for electric vehicles, the relationshipbetween vehicle mechanical braking force and regenerative braking force of the vehicle,the relationship between the front and rear wheels of the front and rear mechanical brakingforce relationship of the regenerative brake force. The models of vehicle parts and brakingstrategy were built with Matlab software, and then imported into Advisor to form anexperiment simulation platform for the electric vehicle. Experiment simulations were donein a typical cycle. Baking force, the effect of regenerative energy, and the effect of brakecontrol strategy in the ECE cycle conditions were evaluated. The realization ofregenerative-hydraulic braking was discussed in this paper. The discussion was mainlyabout realization of regenerative braking, hydraulic braking and coordination betweenthem. Because the Advisor software driving cycle lacked emergency braking strategy, thispaper proposed ways of emergency braking condition based on Advisor software. Verifiedby simulation, the result showed that the braking distance reduced much more throughsuch control strategy than through the original control strategy in Advisor software, whichensured the safety performance of the emergency braking.