LPV supplementary damping controller design for a thyristor controlled series capacitor (TCSC) device

In this paper, the Linear Parameter Varying (LPV) controller design technique is applied in the design of a supplementary damping controller (SDC) for a Thyristor Controlled Series Capacitor (TCSC). The power system model with TCSC devices is linearized at different operating points to obtain an LPV open loop model, whose state space entries depend continuously on a time varying parameter vector. Appropriate scheduling parameters are chosen and a suitable grid is formed in the entire parameter space. The locations of the TCSCs with their controllers are carefully chosen based on the analysis of mode shapes as well as the calculation of the modal controllability. An LPV damping controller for TCSC is then designed based on a single Lyapunov function under some realistic constraints. Comparisons from simulation results are presented between an LPV SDC and an H_infin SDC, which show that the LPV SDC can guarantee robustness over a wider operating range as well as allow more flexibility in achieving specific performance objectives at each operating point