Effect of Volt/Var Control on Optimal Hosting Capacity of Distributed Energy Resources

Today, distributed energy resources (DERs) are being planned for grid installation or are already generating power for the grid. Since DERs capable of participating in Volt/Var control are fully functional, the impact of Volt/Var on the existing grid should be evaluated during the design phase. Therefore, the objective of this study is to investigate the impact of Volt/Var control on the hosting capacity (HC) of DERs. For this purpose, this study optimally allocates the DERs to minimize the objective function consisting of installation cost, voltage variation and losses. The algorithm of Volt/Var control of DERs is implemented in the steady state power-flow analysis in MATLAB. Particle Swarm Optimization (PSO) with the objective function to minimize the operational cost (e.g., cost, voltage fluctuation, and loss) is combined by the NewtonRaphson method. To make the optimization more practical, the load profile at hourly intervals and the generation cost are calculated by the energy mix of the United States. As a case study, the proposed method can usefully evaluate the effect of Volt/Var control on voltage and loss by solving the HC optimization problem.