Allocation and design of robust TCSC controllers based on power system stability index

Stabilizing control for power system stability has been applied to generators equipped with an excitation controller and speed governor. Power electronics-based control devices have been the focus of research and development for the improvement of transient stability. Power electronics control devices are utilized for control of the power flow on a transmission line or the reactive power in a power system. In that case, they have no constraint of setting point in a power system. On the other hand, the total number of these devices to be equipped has economical constraints, because their prices are very expensive; therefore, the allocation problem of these controllers is worth studying. This paper proposes an approach to determine the numbers and locations of thyristor-controlled series capacitors (TCSC) in a multi-machine power system. The index of optimal allocation of the controllers is the power system stability. First, the steady-state stability is considered, and then the transient stability is examined to find a robust allocation of the TCSC controllers.