A modified backward/forward method for fast solving radial distribution networks

Many optimisation problems in the field of distribution automation are solved by means of heuristic techniques which require the knowledge about the system´s state in a short time and for many operating conditions. In this paper a solution method for radial networks is set up. The methodology has good convergence properties and can be employed for the above mentioned problems treatment. It is based on the well-known iterative backward/forward method, whose implementation is strongly modified as compared to those that are present in literature. Since the method is iterative, for which the state variables are the nodes voltages, the loads can have whatever dependency on the supply voltage. The methodology is applied to a set of partial networks without branching nodes obtained from the original network and, differently from the classical backward/forward methods, the variables calculation is carried out starting from the terminal nodes up to the root of the partial networks; in this way it is possible to verify the convergence of the process on a single variable and to accelerate the convergence by updating the values of the load currents during the iteration. After the presentation of the general problem and of the relevant state of the art, the proposed methodology is detailed. The performance has been tested on various networks and the obtained results confirm the excellent results in terms of calculation times.