Power flow analysis of radial and weakly meshed distribution networks

With increasing penetration of distributed generation, and the evolution of predominantly radial distribution systems into weakly meshed networks, it has become necessary to suitably update power flow solution techniques. This paper presents an unbalanced three-phase power flow solution method that is effective in the analysis of modern active distribution networks. The proposed approach is based on the development of a Branch-Current Matrix (BCM), and uses it in conjunction with the line Primitive Impedance Matrix (PIM) to obtain the power flow solution. This approach is initially applied to radial networks and then modified to include the case of weakly-meshed networks. The presented approach takes into account most of the special features of the distribution networks and uses neither LU-decomposition, nor Y-bus formulation/factorization and hence it is computationally efficient. The proposed method is tested on 13-node and 76-node unbalanced networks. Results of the proposed method are compared with some other methods presented in the literature.