Symbiotic Organism Search Algorithm for Optimal Size and Siting of Distributed Generators in Distribution Systems

This paper presents a new approach for solving optimal placement of distributed generation (OPDG) problem in distribution systems for minimizing active power loss. In this research, the loss sensitivity factor is used to identify the optimal locations for installation of DGs and symbiotic organisms search (SOS) is used to find the optimal size of DGs. The proposed SOS approach is defined as symbiotic relationships observed between two organisms in the ecosystem, which does not need control parameters like other meta-heuristic algorithms. The OPDG problem is considered with two different scenarios including Scenario I for DGs installed at candidate buses to supply only active power to the system and Scenario II for same as Scenario I except that DGs are controlled to supply both active and reactive powers at a 0.85 p.f. The effectiveness of the proposed SOS method has been verified on the IEEE 33-bus and 69-bus radial distribution systems. The result comparison from the test systems has indicated that the proposed SOS is effective to obtain the optimal solution for the OPDG problem.