Simultaneous stabilisation approach for power system damping control design through TCPAR employing global signals

A robust damping control design methodology for a thyristor controlled phase angle regulator using global signals is proposed based on the simultaneous stabilisation approach. The numerical design algorithm determines the controller parameters in order to guarantee closed-loop poles in the left half plane with preferential treatment to those corresponding to the inter-area modes. Plant models under different operating conditions are incorporated in the design formulation to achieve the desired performance robustness. A three-input/single-output controller is designed for the TCPAR to provide adequate damping to the critical inter-area modes of a study system model. Based on the observability of the inter-area modes, real power flows from remote locations are used as feedback stabilising signals. The damping performance of the controller is examined in the frequency and time domains and is found to be robust against varying power-flow patterns, nature of loads, tie-line strengths and system nonlinearities, including saturation.