Reliability Evaluation of Radial Distribution Feeder Considering Two Load Modelling of Forecasted Electric Vehicle Load

Abstract

The use of an electric vehicle (EV) in place of an internal combustion engine reduces pollution and produces zero emissions. EVs need considerable electrical energy from the grid, and therefore it is necessary to evaluate the performance of the radial distribution system, including the Electrical Vehicle Charging Station (EVCS) load. The future EVCS load is forecasted using Holt's model, and then it is applied uniformly to the distribution system. This increases the magnitudes of currents, which are calculated using the backward and forward sweep method of load flow analysis. The increased magnitude of current moderates the operating temperature of the components and results in an increase in the average failure rate of feeder line sections. The percentage change in the average failure rate is assumed to be directly proportional to the percentage change in current, which in turn affects reliability indices such as SAIDI and ENS. The reliability analysis needs proper modelling of loads on the system and is taken as light and heavy load, considered this as two load model. The existing load without EVs of the distribution system is taken as a light load and the future load including the EV load during the charging period (5hrs) on the distribution system is taken as a heavy load. In this paper, the reliability indices of a radial distribution feeder are calculated for different cases like without EV load, with EV load and for different percentages of faults during EV load duration and the results are compared. This work is validated on IEEE33 standard distribution system.