Abstract: To ensure the good quality of power in electrical distribution systems, voltages at the different nodes should be within reasonable limits. Shunt capacitors banks installed along with the distribution feeders can supply part of the reactive power required by the inductive loads and hence reduces the voltage drops. Further distributed generators (DGs) also improve the voltage profile as well as provide the local real power generation. The improvement in voltage profile in the system is very much sensitive to the locations and sizes of the shunt capacitor banks as well as distributed generators. In this work, the optimal sitting and sizing of capacitors and DG units are found by the proposed algorithm based on modified particle swarm optimization (MPSO). Loss sensitive factors are used to determine the optimal location of DG units and Shunt capacitor units and their size is obtained by M PSO. The proposed algorithm has been solved by considering multiple objective functions viz., minimization of power loss, minimization of cost function and minimization of deviation of bus voltage. The proposed algorithm has been tested on two test systems i.e., IEEE-33 and IEEE-69 bus systems and results are presented and analyzed.

Keywords: Distributed Generators (DGs), Shunt capacitors, Multi objective function, and Modified particle swarm optimization.