ROBUST DECENTRALIZED H∞ CONTROLLER DESIGN FOR POWER SYSTEMS: A MATRIX INEQUALITY APPROACH USING PARAMETER CONTINUATION METHOD

This paper presents a decentralized H∞ controller design approach for power systems. Initially a centralized H∞ robust controller, which guarantees the robust stability of the overall system against unstructured and norm bounded uncertainties, is designed. The problem of designing decentralized controller is then reformulated as an embedded parameter continuation problem that homotopically deforms from the centralized to the decentralized controller as the continuation parameter varies monotonically. Moreover, the paper proposes an algorithm to solve such problem using two-stage iterative matrix inequality optimization approach to determine the decentralized controller. The approach is flexible enough to allow designing a reduced-order controller for each subsystem with the same robustness condition of the centralized controller. The approach is demonstrated by designing PSSs for a test system.