Effective Load Demand of Electric Vehicles in Power System Adequacy Assessment

The continuous increase of electric vehicles (EVs) has led to several challenges for the reliability of power systems. These challenges are mostly related to the variability of the charging time, duration, and location. Determining the required resources to maintain the reliability of power systems is a key factor in addressing these challenges. This paper introduces the concept of “Effective Load Demand” of EVs (ELD-EVs) in power system adequacy assessment. The ELD-EVs is defined as the amount of extra generation needed to restore the initial reliability level (i.e., the reliability level prior to adding the load of EVs). Also, this paper establishes a load profile that depicts the charging time, duration, and location of EVs. The load profile is represented in terms of weekly, daily, and hourly charging load data over one year. The estimation of the ELD-EVs is demonstrated on the IEEE Reliability Test System for several case studies. In all case studies, an equivalent load of 30,000 EVs with different charging patterns is determined. Monte Carlo simulations are used to evaluate the well-known power system reliability indices and the ELD-EVs. The resulting ELD-EVs can be used to determine the amount of the extra generation needed to maintain the reliability of a power system.