Inclusion of the risk of cascading transmission line outages in the optimal TCSC placement based on self-organized criticality theory

The increasing demand for electric energy has resulted in the operators' tendency toward the full utilization of available resources and capacities in the generation, transmission and distribution of electrical energy. Such an attitude raises concerns about the reliability of the power system and causes cascading line outages, which are known as the major cause of recent blackouts. The reliability of the power grid can be enhanced by building new generation centers and transmission lines, which are restricted to environmental factors and budgetary problems. Considering such technical concerns, power system operators have recently employed flexible alternating current transmission system (FACTS) devices as a promising solution to improve power transfer capability and enhance the transmission system reliability with minimal capital costs. In this paper, an attempt has been made to investigate the long-term impact of optimal thyristor-controlled series compensator (TCSC) placement on the mitigation of cascading line outages. Accordingly, a probabilistic optimal TCSC placement (OTP) based on self-organized criticality (SOC) theory is proposed to minimize the risk of blackouts. The objective function of the optimization problem is expected energy not supplied (\(\:EENS\)) obtained by the simulation of the AC version of ORNL-PSerc-Alaska (AC-OPA) model. The optimization procedure is executed with different numbers of TCSC devices. To find the best optimal scenario, a benefit/cost analysis is introduced here, along with the optimization procedure. The simulation results on the IEEE 118-bus test system reveal the benefits of the long-term impact of the proposed probabilistic OTP on the mitigation of sequential outages of transmission lines.