Parallel Dual Tabu Search for Capacitor Placement in Smart Grids

This paper proposes parallel dual tabu search (PDTS) for capacitor placement in smart grids. The proposed method makes use of the dual code of the initial vale to make solution candidates diverse. The capacitor placement is one of important problems to maintain the nodal voltage profile in the distribution network level of smart grids. The problem formulation of capacitor placement may be expressed as a combinatorial optimization problem of capacitor banks. In this paper, a new method is proposed to improve the performance of tabu search (TS) of meta-heuristics. Although meta-heuristics are not affected by the initial value in smaller systems, they are inclined to give different solutions with different initial values in large-scale problems. In practice, it is very important to set up a good initial value for tabu search although a priori knowledge is not available in general. This paper focuses on the dual code of the initial value to create another initial value systematically. Mathematically, the dual code is orthogonal to the original one so that the solution search is carried out to keep the diversity of solution candidates from two most different directions. The effectiveness of the proposed method is demonstrated in a sample system.