Study of Fuzzy PID Control for Regenerative Braking Converter of Electric Vehicle

An energy reclaimed scheme using super capacitor as energy storage element to realize the regenerative braking of electric vehicles was presented.DC/DC converter of electric vehicle control system,buck chopper and boost chopper of motor driver were analyzed.Fuzzy self-tuning PID controller of the DC/DC converter was designed.The simulation research indicates the following conclusions:(1) The super capacitor with the fuzzy self-tuning PID control system still keeps the carrying output voltage of 2.5 s at about 150 A of discharging electric current when regenerative braking system is at the state of buck chopper.The energy stored by super capacitor supplies to electrical motor rapidly,which increases drive current effectively,improves starting and accelerating performance.It also extends vehicle's working time and increases driving distance at rated power output.(2) The electric current of the super capacitor with the fuzzy self-tuning PID control system fluctuates according to the instructions when regenerative braking system is at the state of boost chopper.Its voltage rises incessantly from 120 V.This shows the energy stored by super capacitor is made the best using,which can realize a high level energy recovery.