The Impact of Grid Uncertainties on Optimal Transmission Switching

Abstract

Optimal transmission switching is proposed to reduce transmission congestion and optimize the system operational cost. Such switching decisions are usually determined in the day-ahead stage. However, the load and renewable generation forecasts may have significant deviations from the actual values in the next day. Thus, grid uncertainty is a critical factor in the decision-making process of optimal transmission switching. This paper investigates different approaches for optimal transmission switching under uncertainties. Deterministic optimization methods and stochastic programming methods are compared through a series of numerical studies. And the impact of grid uncertainties on optimal transmission switching is analyzed. The numerical analysis on the IEEE-118 bus system shows that the deterministic approaches can perform well when there are only small uncertainties in the grid. However, the stochastic programming approach is more preferable when significant uncertainties exist in the system.