Unbalanced Distribution Network Planning by Sitting and Sizing of Distributed Generation and Harmonic Filter Due to Losses and THD Minimization

The necessity for flexible electric systems, changing regulatory and economic scenarios, energy savings and environmental impact are providing impetus to the development of Distributed Generation (DG), which is predicted to play an increasing role in the electric power system of the future. The optimal placement and sizing of generation units on the distribution network has been continuously studied in order to achieve different aims. This paper describes planning of distribution systems in two scenarios. In the first scenario, optimal distributed generation allocation for voltage profile improvement, loss and Total harmonic Distortion (THD) reduction in distribution network has been implemented. Whereas, DG cannot reduce THD to the optimum range, in the second scenario an active filter and a capacitor is used to reduce THD as much as possible. Because of THD and Losses are based on different objective function, a "compromise programming" model that attains the "best compromise" among the conflicting objectives is introduced to overcome on this problem. Harmony Search Algorithm (HSA) was used as the solving tool, which referring two determined aim; the problem is defined and objective function is introduced according to losses, security and THD indices. The applied fast harmonic load flow method is based on the equivalent current injection that uses the bus-injection to branch-current (MC) and branch-current to bus-voltage (BCBV) matrices which were developed based on the topological structure of the distribution systems. This method is executed on 12 bus harmonic unbalanced distribution system and show robustness of this method in optimal and fast placement of DG, efficiency for improvement of voltage profile, reduction of power losses and THD. Copyright (c) 2010 Praise Worthy Prize S.r.l. - All rights reserved