The reliability analysis under generator voltage-class-reduction scheme for the short-term power system plan

This paper aims to address the method for reliability analysis under the generator voltage-class-reduction scheme, focusing on the cascading blackout analysis. The voltage-class-reduction operation is an economic approach to balance the maximum local demand and decrease the investment for building a new substation or enlarging the transformer capacity. The redistribution of power flow brought by such scheme might improve the probability of blackouts. We proposed a cascading model to assess the probability of blackout, which included two parts: the one was the slow process which was the scenario to simulate the load increasing and voltage-class-reduction, and the other part was to simulate the cascading failures under each defined scenario. The simulation results indicated that there was a best threshold for identifying whether some generators needed to step-down to the low voltage terminal of transformer branch.