Planning in Microgrids With Conservation of Voltage Reduction

The main focus of this paper is to find an upgrade plan for a microgrid. This plan includes system lines' upgrades, the place, and size of the new capacitors and DERs. As usual, the planning process is begun with the load forecasting. The main objectives include minimization of system upgrade cost, loss cost, loss cost in peak load, and finally demand cost. The last objective is realized here using the tap changer of the main station transformer and reactive power support of the sources available or planned for the future of the grid. This is always referred to as the conservation of voltage reduction. In order to consider the effects of bus voltages on the system demand, the ZIP model for the system loads is used. Particle swarm optimization is used to minimize the total cost. The line flow limits lower/upper bound on bus voltages and minimum/maximum producible active and reactive power from different sources are considered as the optimization constraints. The proposed algorithm is tested on the IEEE 69 bus test system and the results are discussed.