The Efficient Electric Vehicle Drive System Design Based On Ultracapacitor

As a kind of green transport, electric vehicles got the relatively rapid development in recent years, however,electric vehicles battery can not charge and discharge with large current, which greatly weakens the start, acceleration and climbing performance of the electric vehicles, and it also can not recovere the electric energy when the car brakes.This article will ultracapacitor into the electric vehicle drive system and brushless DC motor drive system, ultracapacitors drive system have been designed accordingly, which improve the performance of electric vehicles and the overall energy efficiency of the drive system,based on the high power density and high-current charge and discharge characteristics of ultracapacitors’. The main work of this paper includes the following aspects:(1) This article introducts the brushless DC motor and ultracapacitor, then describes the working principle of electric vehicle drive system and proposes the topology of the drive of the brushless DC motor and the ultracapacitor, which compose the entire structure of the drive system.(2) This article analyses the brushless DC motor in drive state and electric regenerative braking state, then proposes control strategies correspondingly and designs PI controller of the brushless DC motor; at the meantime, analyses the ultracapacitor in charge and discharge state, then proposes control strategies correspondingly and designs PI controller of ultracapacitor.(3) This article designs the software and the hardware in details and a series of experiments is done, and the result demonstrate the effectiveness and reliability of the hardware,software and control strategies.