Fast and reliable distribution system load flow algorithm based on the YBUS formulation

This paper presents a new and efficient method for solving the load flow problem in distribution systems. A simple algebraic matrix equation to solve the load flow problem is derived by using the complex power balance equations. By adopting the rectangular coordinate, which requires the neglect of only second order terms in the linearization procedure, the proposed method gives better convergence characteristics than the conventional Newton Raphson (NR) or the fast decoupled load flow (FDLF) methods. Only diagonal elements of the Jacobian matrix are subjected to be updated while other elements remain constant. This enhances the proposed algorithm considerably in computation speed. The proposed method can be applied to both radial and meshed networks. The proposed algorithm is tested with 33, 302, 700, and 1004-bus sample systems. The test results show that the proposed method can be well applied to the distribution system with wide ranged R/X values. The computation speed is remarkably improved compared with the conventional NR and FDLF methods