Power Flow Analysis for Islanded Microgrids

Abstract

Power flow studies are very important in power system planning and operation. Several well developed schemes are available to solve the power flow analysis. However, in the past decade, due to integration of renewable energy resources, power system has undergone a drastic change. After deregulation in the power sector, distributed generation (DG) has become a very important part of the power system, which resulted in the evolution of micro-grids. Hence, the study of power flow analysis for microgrids has gained importance. The conventional approaches to solve power flow using Gauss Seidel (GS) and Newton Raphson (NR) are not valid in case of islanded microgrids due to the absence of slack bus as well as the dependence of the power on frequency as a result of droop characteristics. Therefore, in this work, the conventional methods are modified, and with simple but effective modifications in the existing conventional methods (Gauss Seidel and Newton Raphson), power flow for islanded microgrids is computed. The proposed methods provide simple, easy to implement, and accurate approaches to solve the power flow analysis for microgrids. Proposed methods are implemented on two test systems: a 6-bus system and a 38-bus system and different case studies are presented in this work. The results are compared against simulations results from PSCAD/EMTDC which validate the effectiveness and robustness of the proposed methods. Since the developed techniques are modified from conventional approaches, they can be easily integrated in current commercially available power system software and can be applied for power system studies.

Date of Award	May 2015
Original language	American English
Supervisor	Hatem Zein El din (Supervisor)