Optimal Allocation of DG Using Exponentential PSO with Reduced Search Space

In the current deregulating environment, integration of Distributed Generation (DG) in the radial distribution network is one of the reliable and efficient options which can be used for reduction of power loss, improving the voltage profile of the system and stability. Optimal allocation of DG units is essential for improving the quality of supply and reliability of the network. Using voltage stability index, weak and healthy zone are determined. DG with same size is placed in weak and healthy zone separately. The voltage profile improvement, cost of energy saving and reduction of losses can be maximized by placing DG in weak zone. To reduce the computational time required for optimal allocation of DG, it is proposed to conduct its performance analysis only at the weak bus locations of the system. Therefore, the search space for optimal allocation of DG can be restricted only to the weak zone of the system. Taking account of operational constraints, a new objective function is formulated considering Voltage Profile Improvement Index (VPII) and Benefit to Cost ratio (BCR). An Exponential Particle Swarm optimization (EPSO) method is proposed for optimal placement and sizing of DG considering both full and reduced search space. The proposed algorithm is compared with other types of Particle swarm optimization techniques (PSO) such as Simple Particle Swarm Optimization (SPSO) and Adaptive Particle Swarm Optimization (APSO). The best performance in terms of computational efficiency and solution quality is achieved for the proposed EPSO method.