Application of Modified Impedance Matrix to Determine an Initial Solution for Reactive-Power Compensation Problem

As an optimization problem, reactive-power compensation (RPC) in distribution networks has variety of technical and economical objectives and constraints. In order to solve the RPC problem, classic and heuristic methods have been applied. In distributed networks with large amounts of equipment, the RPC has a large dimension which could be a challenge for the aforementioned methods. So, having an initial guess or solution for buses that are suitable for compensator installation, lessens the mentioned challenge and thus improves performance of the solution procedures. Applying extended impedance matrix, this paper proposes a method to determine initial solution for the RPC problem. “Extended” means loads connected to buses are included in the impedance matrix. Inclusion of loads in the matrix gives more realistic initial solutions. The rationale behind it is that buses with more loads usually need more reactive composition. Two ranking lists of the buses that could be nominated for RPC have been considered in this paper: One list is obtained by the proposed method, and the other by the sensitivity analysis. Comparison of the mentioned lists in two typical distribution systems shows acceptable performance of the proposed method.