A Simplified Forward and Backward Sweep Approach for Distribution System Load Flow Analysis

This paper presents a simplified forward and backward approach for load flow analysis in radial distribution system. The proposed method includes two phases. At Phase I (forward sweep), the KCL and KVL are used to find the calculated voltage for each bus located at upstream of each line segment or transformer. At Phase II (backward sweep), the linear proportion concept for real and imaginary decomposition is adopted to find the ratios of real and imaginary parts of specified voltage to the calculated voltage at each upstream bus. Then, the voltage at each downstream bus is updated by real and imaginary parts of initial or calculated voltage multiplying with the corresponding ratios, respectively. The solution procedure is terminated after the mismatch of calculated voltage and specified voltage of substation is less than the tolerance value. The proposed method is tested with three IEEE distribution benchmark systems. Results show that the proposed method is effective, computationally robust, and faster than conventional forward/backward sweep and the ladder iteration method.