Evaluation of optimal-reliability indices for electricaldistribution systems

A method to calculate the optimal values of reliability indices for a load point in an electrical distribution system is presented. The problem is formulated as an optimization problem and solved by the gradient projection method; the objective is to minimize interruption cost. The algorithm is very useful and powerful for extending the existing network and planning new networks. It has been tested on a practical system (the Port-Fouad power network), and the results are discussed. Once the optimal reliability indices are determined, modification of the system by equipment replacement and future system planning can be done in such a way that the interruption cost is minimized