Investigation on reliability and cost in the presence of electric vehicle charging station

In the near future we will see an expansion in the Electric Vehicles across the country. Conducting a thorough reliability analysis of the system with charging patterns of EVs and their impact on the distribution grid will greatly aid in the planning and development of the supporting infrastructure mainly the Electric Vehicle charging stations (EVCS). The reliability of the system changes with change in the failure rate, outages per year, average outage duration etc. The reliability indices are broadly categorized into customer based indices and energy based indices. A load pattern is established for a 24 hour period for 800 vehicles. This load curve is placed in the IEEE Standard 33-bus system and the indices System Average Interruption Frequency Index (SAIFI), System Average Interruption Duration Index (SAIDI), and Customer Average Interruption Duration Index (CAIDI), Energy Not Supplied (ENS) and Average are Energy Not Supplied (AENS) are calculated before and after placement of the Electric Vehicle Charging Stations. A comparative study can be performed using the obtained results to get an estimate of the system response in the presence of EVCS. The rise in peak demand gives rise to various power quality issues like drop in voltage levels or the power factor. A methodology is devised for calculation of penalties to be paid by the utility if the power quality drops below a certain value and thereby establishing the need to maintain it.