A Multi-Port Approach to Solve Distribution Networks with Meshes and PV Nodes

A new methodology based on the backward/forward (b/f) technique for the load flow solution in distribution systems is here proposed. The methodology takes efficiently into account the fixed voltage nodes and uses a reduced bus impedance matrix. In this way, it is possible to attain, for the unknowns at the PV nodes, the same values that are attainable solving the network with the methods adopted for transmission systems. With the same methodology it is possible to take into account also the meshes. If the network contains only meshes, the relevant model is linear and it is the one including the compensation currents. The presence of PV nodes introduces non linearity in the model and an iterative method is required to solve it. In this case, in the solution process, two cycles are present. An external main cycle connected to the b/f method and an internal cycle due to the presence of meshes and PV nodes. After the presentation of the used methods to take into account the presence of meshes and PV nodes, the new proposed method and its implementation are detailed. The results of the applications carried out show that the developed methodology presents, else than a high precision, good convergence properties and speed, qualities that are not dependent on the loading level and on the number of PV nodes.