Design of a switched control with pole location constraints for a UPS system

This paper addresses the design of a switched controller that guarantees a performance based on pole location specifications for an uninterruptible power supply system with a typical load. Sufficient conditions in terms of linear matrix inequalities are presented in order to determine a switched state feedback control law that assures: i) the pole location inside a circle for each linear mode of operation of the system, improving the transitory response whenever the switchings allow the accommodation of the system dynamics; ii) the overall stability of the closed-loop system for any arbitrary switching sequences. Structural constraints such as decentralization are also addressed and simulation results show that a switched control strategy permits to impose more stringent design specifications for the closed-loop uninterruptible power supply system, providing dynamical performances that could not be achieved by means of a fixed feedback gain.