Optimal Distributed Generation and Capacitor Bank Allocation and Sizing at Two Voltage Levels

Optimal simultaneous allocation and sizing of distributed generation (DG) units and capacitor banks (CBs) can effectively reduce real power losses and improve voltage profile. This article presents a method for simultaneous allocation and sizing of DGs into medium-voltage (MV) and low-voltage (LV) networks and CBs into LV side of MV/LV transformers to reduce losses and improve voltage profile in LV nodes without the increase in investment costs. The proposed method was performed with a modified genetic algorithm and demonstrated on IEEE 33 bus radial distribution system that was MV/LV transformers and LV line models. The ordinary model that consists only of MV nodes was extended for the purpose of monitoring the impact of DGs and CBs allocation on both the MV distribution network and on the LV networks that are fed from MV/LV substations. The simulations showed that better results in the coordinated allocation of DGs and CBs can be achieved by using a more detailed model with included elements of two voltage levels of the distribution network, and by considering the allocation of DGs on two voltage levels and the impact of the allocation of DGs and CBs on the MV network and the LV network.