Effects of Electric Vehicles and Charging Stations on Microgrid Power Quality

Abstract

In this study, integration of renewable energy sources and Electric Vehicles (EVs) into a micro-grid was modeled and analyzed. The microgrid is divided into four important parts; a diesel generator, acting as the base power generator; a photovoltaic (PV) farm combined with a wind farm, to produce electrical energy; a vehicle to grid (V2G) system installed next to the last part of the microgrid which is the load of the microgrid. The size of the microgrid represents approximately a community of a thousand households during a low consumption day in spring or fall. There are 100 electric vehicles in the base model which means that there is a 1:10 ratio between the cars and the households. This is a possible scenario in a foreseeable future. The continuous increase in their rate in energy production makes micro-grids important. Microgrids can be designed to meet the energy needs of hospitals, universities or charging stations of electric cars, as well as to meet the energy needs of a district, village or industrial site. Charging stations are needed to charge the electric vehicle battery. In this study, the effects of electric vehicles on the microgrid network are analyzed. Electric vehicles have non-linear circuit elements in their structures. Therefore, they are a source of harmonic current in the microgrid. They negatively affect the power quality of the microgrid. The battery in electric vehicles is charged with direct current. The alternating current from the microgrid needs to be converted to direct current.