Real Time Congestion Management in Power Systems Considering Quasi-Dynamic Thermal Rating and Congestion Clearing Time

Abstract

In a smart power system, smart measurement infrastructure brings so many advantages in monitoring and control of the power system. This paper proposes an optimal real time transmission congestion management algorithm in a competitive electricity market based on real time measurements in a smart power system. Instead of static and fix thermal rates, quasi-dynamic thermal rates of transmission lines are calculated and used to solve the real time congestion management optimization problem. The optimization problem includes an optimal generation rescheduling and load shedding scheme to minimize the congestion management costs in a specific time interval. This time interval is introduced and defined as congestion clearing time in this paper. Furthermore, in the proposed algorithm, the congestion clearing time is divided into few subsequent subintervals aimed at considering loads and power system variations during rescheduling procedure. The proposed method could be used by system operators (SOs) to adapt the real time congestion management procedure with regard to the power system loads and generations, or system configuration variations during rescheduling and load shedding process. Numerical results obtained from running the algorithm on the modified IEEE 30-bus test system and the transmission network of Esfahan Regional Power Network (ERPN), as a real size power system, demonstrate convincingly the ability of the proposed algorithm in the congestion management cost and load shedding reduction, while it increases the power system security margin in intensive congestion cases significantly.