Optimization-based tuning and coordination of flexible damping controllers for bulk power systems

This paper proposes a simultaneous tuning approach for power system damping controllers which seems better able than current SISO-based methods to cope with the foreseeable increase in system complexity and adverse interactions. To tackle the most difficult situations, the retained control architecture comprises several degrees-of-freedom in terms of dynamic feedback loops, each consisting of a high-order differential filter. The tuning of these flexible controllers is then performed by minimizing a selective modal performance index in the parameter space. Adding stability and robustness constraints greatly improves the engineering significance of the resulting design. Three examples adapted from the literature are used for illustration: a robust power system stabilizer (PSS) for a single-machine infinite-bus system with multiple operating points, a thyristor-controlled series capacitor (TCSC) controller for a large power system, and a coordinated design of multiple PSSs for a two-area/four-machine test system