Research On The Supercapacitor Applied To Solar Electric Vehicle

As energy and environment problem increasingly prominent, the electric vehicle(EV) has become a new type of car which are developing rapidly in recent years. Supercapacitor as a new type of energy storage device can meet the requirements of instantaneous power that EV needs while staring off, and recycle the energy the motor generate while EV braking. However, the supercapacitor voltage changes a lot while discharging, which has a adverse impact on motor driving. And the lower energy density seriously limits the ranges of the EV. This paper puts forward to a new energy system of EV with supercapacitor giving priority to and supplied by solar energy, and studies the related knowledge.First, the paper summarizes the research status on solar EV and the supercapacitor in EV on the application at home and abroad, puts forward a new EV energy system and analyzes the general designing.Secondly, this paper analyzes the principle of super capacitor energy storage, studies the supercapacitor charging and discharging characteristics based on its Simplified equivalent circuit model, and discusses the voltage-balancing technology of Supercapacitor energy storage system, uses the power electronic and motor control simulation software PSIM to simulate DC/DC converter method equalization circuit.Thirdly, this paper introduces the photovoltaic(PV) cells and its working principle, does mathematical modeling on PV system and makes a simulation model by using Matlab/Simulink toolbox. Then, the paper introduces three kinds of maximum power point tracking(MPPT) controlling methods and their working principle, makes a simulation model of Perturbation and Observation method,Finally, the paper does some research on the bi-directional DC/DC converter for the supercapacitor storage. These research concludes:analyzing the alternate operation mode of non-isolated Boost/Buck bi-directional DC/DC converter, constructing its small signal mathematical model by applying the state space average method, and making a simulation model by using Matlab/Simulink toolbox.