Optimal distributed generation placement in shunt capacitor compensated distribution systems considering voltage sag and harmonics distortions

The present study proposes a method of solving the distributed generations (DGs) placement problem by considering multiple aspects of a power system operation. In addition to the commonly considered objectives of reduction of the loss and improvement of the voltage profile, this study has optimised other power quality related objectives such as minimisation of the voltage sag and harmonic distortion. A new formulation of a composite, constrained objective function is put forward by considering objectives such as the cost of the power losses, the cost of the DGs and the cost of loss of load because of the voltage sag and the constraints such as line flow limits, number/size of the installed DGs and the power quality limits of the standard IEEE-519. The system under consideration is a complex one consisting of both linear and non-linear loads as well as the power factor correcting capacitors. The effect of the non-linear harmonic generating loads and the compensating capacitors on the penetration of the DGs in the distribution system is investigated. This optimisation problem is solved for several distribution systems by using several metaheuristic optimisation techniques. However, detailed results are presented on a benchmark IEEE 33 bus radial distribution system using genetic algorithm to demonstrate the effectiveness of the proposed method. A comparative performance analysis of various metaheuristic optimisation techniques is also presented to show the applicability of different optimisation techniques in solving the proposed optimisation problem.