Simulation Of Brake Energy Recovery System And Design Of Controller For EV

With the rapid development of vehicle industry, vehicle stock of the world rapid grows up. The negative impact of energy shortages, environmental pollution, global warming caused by automobile becoming more and more serious. As a new automobile, the EV (electric vehicle) is the most effective way to solve the energy crisis and environmental pollution.The short driving distance of EV is still the major problem that hinders the development of EV. Increase the capacity of the battery is the most effective way to solve driving distance of EV. However, battery energy storage technology will be no major breakthrough in the near future. So, driving range of EV mainly relies on increasing energy utilization factor. A key breakthrough of energy efficiency of EV in technology is how reasonable and efficient change mechanical energy into electricity and stores it into the storage device.The subject based on the engineering project of pure EV "the research of test automobile of pure EV" (authorization number:2001K10-G1) to study the simulation of brake energy recovery system and the design of controller.Force analysis of EV braking process and establish a dynamic model of the braking system based on some constraints of EV braking energy recovery and simulation based on Simulink. Control strategy is making braking current constant and using PID controller to control D of DC/DC converter. Motor armature current can follow the brake pedal in the braking condition. Experimental results shows:(1) When the demanded braking force is less than the maximum braking force that motor can supply. EV's braking force is provided by the electrical braking system. Comply with safety requests and constraints of brake, the greater the motor armature current, the greater the braking power, shorter braking distance and can recovery more braking energy. (2) When the demanded braking force is larger than the maximum braking force that motor can supply. EV's breaking force provided by the composite braking system, this system can supply much more breaking power and make the braking distance shorter but regenerate less braking energy. Design a controller of EV braking energy recovery in the paper last. The controller is based on the Freescale MC9S12DG128. Controller mainly consists of four modules:data acquisition module, data display module, data communication module, drive/brake control module. At last, design hardware and software flowchart of the four modules. Primary Controller, Power Converter-IGBT, Motor Mechanical Properties and Sensors have been tested by EV's test bed and got ready for braking energy recovery test.This research work has some practical significance in the field of brake energy recovery of EV.