Improving the Voltage Stability of a Distribution System With Renewable Distributed Generation Using a Three Method Hybrid.

Abstract

Owing to the increased advocacy on clean energy sources worldwide, the integration of Renewable Distributed Generators (RDGs) in to the grid has been increasingly adopted in meeting increased electrical load demand. RDGs are intermittent in nature posing a great problem to the system’s voltage stability due to their variable power output. Therefore the study of voltage stability with Renewable Distributed Generation integrated in the distribution system is very critical in modern power system operation. The formulation and solution of the voltage stability problem of a radial distribution system with Renewable Distributed Generation (RDG) is crucial. Earlier research works show that optimal penetration of RDGs to the grid near the load centers can improve the system reliability, voltage stability and power quality through reduced transmission line losses. However, a further increase in RDG penetration distorts the system’s voltage stability. This thesis work comprised of a multi-objective problem formulation aimed at reducing the total line losses (both real and reactive) and the total voltage deviation of a radial distribution system with Photovoltaic Solar sources and wind sources. A three method hybrid approach of Index Based Planning, Adaptive Genetic Algorithm and Simulated Annealing was applied in solving this problem. Results show that the three method hybrid can be used to optimally size and locate two RDGs in a radial distribution system while reducing the total line losses and total voltage deviation simultaneously. The integration of two PV Solar RDGs into the IEEE 33 Bus System reduced the total line losses and total voltage deviation by 62% and 73% respectively. The integration of two wind RDGs into the IEEE 33 Bus System reduced the total line losses and total voltage deviation by 76% and 70% respectively. Integration of a third RDG in to the system did not have any significant effect to the system’s total voltage deviation and total line losses.