Securing highly penetrated wind energy systems using linearized transmission switching mechanism

Abstract

The increasing penetration of Wind Energy Sources (WES) in an ac-network requires more Flexibility Resources (FRs), such as thermal units and transmission topology control by transmission switching (TS) action. The FRs, especially the TS action, can help to accommodate the intermittent and volatiles from WESs. Nevertheless, obstacles still remain and must be dealt before the TS action can be implemented by the real power systems. Indeed, the challenges comprise AC feasibility, the ability to handle large-scale real power systems and computational complexity. This paper investigates these challenges by developing the TS based on a linearized AC network (LAC-based TS) model that includes a linear representation of reactive power and bus voltage magnitudes. The proposed LAC-based TS model can handle high penetration of WES uncertainty in the stochastic security constrained unit commitment (SCUC). Also, the WES is the only source of uncertainty considered in this paper, which is modeled through an appropriate set of scenarios. Accordingly, the proposed model is formulated as a two-stage stochastic programming problem, wherein, the first-stage relates to the day-ahead scheduling, and the second-stage refers to the real-time operating conditions. An iterative algorithm based on the Benders decomposition method is used to solve the problem. The performance of the proposed model is investigated in details using a modified 6-bus and IEEE 118/662-bus test systems.