DC Smart Grid System for EV Charging Station

Abstract

Increasing the use of electric vehicles (EVs) is regarded as the right step to overcome the air pollution and carbon emission. Economic Times report, Government of India, is spending Rs. 5.65 lakhs crores for importing crude oil in 2017–2018. This huge amount of import affects our economic status and increases dependence on Arab and Eastern countries. In order to overcome this fossil fuel dependence, electrical vehicle is the ideal solution. But major difficulties to implement EV are stepping up the charging station across the country and to reduce transmission losses and distortion across smart grid network. In AC smart grid system, distortion and harmonic losses frequently occur; moreover, most of storage batteries and EV are DC. Hence, an AC/DC converter is required for an AC smart grid system. In DC smart grid system, distortion and harmonic losses are nullified. In India, we mostly use solar energy and fuel generator, and in case of wind energy AC source can be converted into DC using AC/DC converter. This paper models an integrated electric vehicle charging battery storage system and motor load operating in the presence of DC source smart grid. The major constraints are voltage quality maintenance and reduction of EV charging time. Both of these constraints are achieved using SEPIC converter. Using this converter, higher output voltage is achieved to drive a motor load.