INTEGRATION OF ELECTRIC VEHICLES IN ELECTRIC POWER SYSTEMS

With the expected integration of Electric Vehicles (EVs) in the light-duty vehicle fleet, the transportation sector will undergo significant changes. EVs will promote the diversification of final energy consumption sources in a sector where most of the fleet would run on petrol derivatives, diesel and gasoline.

 

This diversification of fuel sources is very welcomed by the society but carries great challenges to the power systems. EVs will need to be recharged and the extra amount of power demanded can lead to the occurrence of several operational problems in the electricity networks. To avoid them and successfully deploy this new technology, adequate recharging strategies must exist that are cost effective and sustainable.

 

Electric vehicles (EV) require fast charging facilities, which will apply high point loads on the LV system.  This can result in disruption of the supply in the network with possible low voltage and power quality issues.  If there is no strategy or control over the location and type of charging facility the result, in the long term, could be disruptive and cause higher energy costs for consumers.  It is important that a charging strategy is developed, which will enhance the operation of the network.  Possible benefits of EV on the system include frequency and voltage control as well as reduction of spillage from wind generation.  In Portugal a reduction of 20% wind generation spillage is considered possible.  Models for determining the effects of EV on the price markets need to be developed.  Research in this area is essential.  This analysis as well as the development of the EV charging strategy requires close collaboration between the manufacturers and the energy suppliers, which was not always the case with use of fossil fuels.  The impact of Ev on the network in the short term is not expected to be large but will become more prevalent as the number of EV’s ‘increases.  It is important that the models are developed and strategies formulated to ensure a smooth incorporation of EV’s into the current LV and MV networks.

 

CIGRE Technical Brochures TB632 studied the impacts and benefits of these issues and integrating EVs in the electric power systems. The results of this investigation are summarized in this technical brochure available from e-cigre.org