Power loss minimization with second order cone programming relaxation

Abstract

The minimization of power loss in distribution systems is very important to increase the reliability and performance of the system. Therefore, this thesis determines power loss minimization in a power system. The active power loss can be minimized by the alternating current optimal power flow (ACOPF) under the limits of power generations, bus voltages, and distribution lines. The general ACOPF problem is computationally intractable in practice owing to the nonlinear objective function and nonlinear constraints. Accordingly, the conventional ACOPF is a nonconvex and NP-hard optimization problem. To address this difficulty, this work develops the computation of the ACOPF by applying second order cone program (SOCP) relaxation. Then, the ACOPF problem is a convex optimization problem. In addition, power system devices, such as distributed generation (DG) or static var compensator (SVC) can vary power loss in the system. Consequently, this work analyzes the appropriate site DG and SVC with optimal size to reduce power loss in distribution line. The proposed work was applied to MATPOWER test systems. The results show that all system parameters do not violate the system limits. The total generated power can supply the total load demand sufficiently. A near-global solution can be discovered. Furthermore, power loss is reduced when DG and SVC are installed with the optimal size at the proper site.