Optimal placing and sizing of DG in a distribution system for voltage stability improvement

Integration of distributed generation (DG) in distribution systems has increased to high penetration levels. The impact of DG units on the voltage stability margins has became significant. Optimization techniques are tools which can be used to locate and size the DG units in the system, so as to utilize these units optimally within certain limits and constraints. Thus, the impacts of DG units issues, such as voltage stability and voltage profile can be analyzed effectively and proposed a method of locating and sizing DG units so as to improve the voltage stability margin. The DG units' sizing is formulated using particle swarm optimization (PSO), with an objective function of improving the voltage stability. DG units are connected in parallel with the utility grid, and they are placed depending on availability of the resources. Integrating DG units can have an impact on the practices used in distribution systems, such as the voltage profile, power-flow, power quality, stability, reliability, and protection. The proposed approach is simulated in MATLAB environment by testing on standard IEEE 33 bus and 69 bus distribution systems.