Design Of Control Strategy And Performance Test Of Energy Saving System Based On DC/DC+Ultra Capacitor

With the increasingly stringent emission and energy-saving standards,automobile industry must need a revolution.Lots of car companies adopt new technology to reduce emission and oil consumption.Start-stop and braking capacity recovery can greatly reduce oil consumption without doing much changes to original vehicle.This paper fulfills some tasks like capacitor selection according to driving condition,simulation with Cruise and real vehicle test based on the system designed by SAIC.Firstly this paper introduces some start-stop systems and marketing status.Next selects the capacity of ultra-capacitor based on driving condition.And then briefly introduces some control strategies of smart generator.What follows is designing the control strategy of start-stop and energy recovery.The strategy uses two methods logic threshold and fuzzy control to design the energy allocation.Both this two methods can greatly reduce the possibility of big current output for battery.Next using AVL Cruise and Matlab Simulink to simulate the running process,which shows that with the system oil consumption can be reduced3.51% under NEDC cycle,3.66% under Japan＿08 cycle,4.16% under Shanghai taxi cycle compared with a normal start-stop system.The last part is about the real vehicle test on a diesel 6MT vehicle,which was done in Shanghai Motor Vehicle Testing Center.And the result shows that oil consumption changed from 5.94L/km to 5.75L/km,which means the system can be reduced oil 3.2% under NEDC cycle.