An improved hybrid method to reduce the effect of islanding in the presence of optimally located DGs

The islanding issue in the distribution system poses great threat to the system during operation. With increased penetration levels of DG, the system is more vulnerable to islanding, leading to the collapse of the system. This paper proposes an improved method to detect the islanding in the system with DG penetration. The proposed work is a two-step method, firstly the siting and sizing of DG is obtained by two stage Genetic Algorithm (GA) to improve the voltage profile and to reduce the active power losses. A two stage GA ensures a faster convergence and better quality of solutions. Finally the proposed improved hybrid method is applied to detect the bus most susceptible for islanding under varying operating conditions. The improved hybrid islanding detection method utilizes the positive features of existing active and passive methods simultaneously. The proposed work is tested on IEEE 33 and 69 bus radial systems and the results obtained are promising.