Optimization of PHEV charging strategy to improve power quality in a residential distribution grid

As a solution to relieving the environmental pollution and energy depletion, plug-in hybrid electric vehicles (PHEVs) are expected to sweep across the market in the upcoming years. However, high penetration of PHEVs may pose a great challenge to the current power grid. A large number of PHEVs charging simultaneously in a small distribution grid can easily increase the peak load, and induce power quality issues such as voltage deviation and frequency change. In this paper, particle swarm optimization (PSO) algorithm is used to control the charging sequence of PHEVs in order to improve the power quality. A new objective function is proposed and used in the PSO algorithm to minimize voltage deviations. Its relationships with other objective functions are also studied. Further, the performances of these different objective functions on reducing voltage deviation and reducing the peak load are studied and compared. This study is carried out on a small residential distribution grid with different PHEV penetrations considering the real-world scenarios.