A backward/forward sweep power flow method for harmonic polluted radial distribution systems with distributed generation units

Abstract

This paper presents a Backward/Forward Sweep (BFS) power flow method in the frequency domain for the analysis of the harmonic distortion in radial distribution systems with distributed generation (DG) units. A detailed procedure for solving the power flow problem at fundamental and harmonic frequencies and the models of distribution system elements in harmonic analysis are presented. In addition, the effects of converter-based and nonconverter-based DG units on voltage profile, power losses, and power quality are carried out. Performance of the proposed method is tested and evaluated on the standard IEEE distribution systems. Simulation results, obtained using the proposed BFS method, are compared with those obtained using the Decoupled Harmonic Power Flow (DHPF) method, Harmonic Analysis module of the ETAP program, and Full Harmonic Solution module of the PCFLO program. It is shown that the BFS method provides effective, robust, and high-quality solutions. Besides that, the proposed method has better computational performance than the commonly used DHPF method, since the bus admittance matrix inverse employed by the DHPF method is not necessary in the solution procedure.