Application of thyristor-controlled series reactor for fault current limitation and power system stability enhancement

Various types of Fault Current Limiters (FCLs) have been proposed and proven to offer numerous advantages with respect to transmission losses, voltage quality, and power system stability. However, FCL research has largely focused on only the FCL system, including optimization of components, efficiency improvement, and cost reduction. Conventional solutions to fault current problems, such as splitting buses, replacing switch gear, and installing permanently inserted series reactors, are still widely used in the field, but impair overall power system reliability. In this paper, a Thyristor-Controlled Series Reactor (TCSR) is used to limit fault current and enhance power system stability simultaneously. A TCSR controller is designed using an advanced mathematical approach and the impact of TCSR is analyzed from the perspective of voltage security enhancement. The benefits of the proposed TCSR-based FCL in terms of both voltage security and angle stability are demonstrated through bulk power system simulation results. The feasibility of real power system application is also assessed using actual power system data.