determination of composite system adequacy equivalents using a reduction technique: a case study on a regional electric company

reliability evaluation of a large-scale composite power system faces to numerous events/outage and consequently imposes an extensive burden of calculations. in order to simplify the problem, determination of an equivalent system for large-scale power system is inevitable. this paper proposes a framework as reduction technique to separate a composite power system to three areas: external area, optimization area and equipment outage area. this separation enables policy makers of power systems to evaluate reliability of large-scale power systems with less time of calculation and extraordinary precision. the reduction technique is applied to composite power system of iran with more than 4600 buses to determine an equivalent network for reliability evaluation of semnan province network. comparative discussions and simulations for case study are presented at the end.