Optimal Placement and Sizing of Renewable Distributed Generation in Electricity Networks Considering Different Load Models

Integration of DGs in utility networks has increased significantly over the past years primarily as a result of growing energy demand, coupled with the environmental impacts posed by conventional fossil fuel-based generation. Improper planning of grid integration of intermittent DGs such as wind and solar PV may however pose negative impacts on the quality of power supplied by utility networks. This paper performs a comparative analysis of optimal placement and sizing between solar PV and DFIG-based DG for PQ improvement in sub-transmission and distribution networks under different load models. GA algorithm is applied to obtain the optimal locations and capacity of DGs using the objective function which takes into account voltage improvement at different network buses as well as reduction of overall active power losses in the grid. The networks used for the analysis are the standard IEEE 9 -bus and 33-bus networks representing the sub-transmission and distribution networks respectively. The simulation of the case studies is performed in MATLAB 2014a. The results provide an understanding of the role of grid-integration of wind and solar-based DG on PQ which is useful in the planning of grid integration of RE in South African networks.