New Load Flow Method S-E Oriented For Large Radial Distribution Networks

There is a growing interest in the electric utilities to raise their efficiency in the operation and design of transmission and distribution of systems. This work proposes a new, fast, robust and efficient method for the load flow solution, in balanced and unbalanced radial distribution systems. It is about a sequential method, based on the S-E load flow algorithm devised for transmission networks by Zaborszky in 1981, which has been adapted to distribution systems, orienting the powervoltage (S-E) iterations, to take advantage ot the radial condition of the latter and extending it to handle unbalanced three-phase systems. The iterative process consists of progressively concentrating the load plus network losses at each node, starting from the farend ends nodes and moving toward the substation. Secondly, the nodal complex voltages are calculated from the substation toward the demand nodes, carrying on with this relatively simple procedure, till reaching convergence. The effectiveness of the algorithm is shown when comparing it against other methods widely used in the specialized literature. In particular it is tested against methods proposed by Ardvinson, Shirmohammadi, Ghosh and Das, Jovanovic and Cespedes. The here-in proposed methodology represents a valuable tool that substantially improves the state-of-the-art of the load flow