A New Approach for Power Flow Analysis of Balanced Radial Distribution Systems

Abstract

Power flow analysis is perhaps the most useful technique in the design and operation of a power system. This paper reports on a new method of power flow analysis for solving balanced radial distribution systems. The proposed method models the radial distribution system as a series of interconnected ladder networks. Using Kirchoff's laws, a set of iterative power flow equations was developed to conduct the power flow studies. It is very efficient and has excellent convergence characteristics. The radial topology of distribution networks has been fully exploited such that a unique branch and node numbering scheme is utilized to achieve storage and computational economy. Due to the voltage dependency of loads in distribution systems, various static load models are incorporated in the power flow algorithm to obtain better and more accurate results. The computer software implemented in this power flow method was then developed using C++ and successfully applied to several practical radial distribution networks. The results were then validated with those obtained from using existing power flow analysis software. The performance of this method was found to be superior in terms of solution time and convergence characteristics to existing power flow methods. This paper also compares the power flow results of a distribution system for the different voltage-dependent load models. The convergence patterns of this power flow method for the various load models were also compared. In addition, the effects of system characteristics on the convergence of the method are highlighted.