A fast decoupled power flow for distribution systems

This article presents a fast decoupled power-flow (FDPF) technique based on line current flows in rectangular coordinates for radial distribution systems. The line current flows, computed from the specified load powers and its functions, are rotated by appropriate line admittance angles for zeroing the off-diagonal blocks of the Jacobian and decoupling the power-flow problem into two sub-problems without making any assumptions. The approach is simple and uses a sparse constant sub-Jacobian matrix that needs to be factorized only once for both real and reactive sub-problems and is solved iteratively similar to the FDPF technique. Test results of 15-, 29-, and 69-node systems indicate that the proposed method is efficient, robust, accurate, and has great potential for on-line applications.