A Nonlinear Adaptive Control System for UPS Systems

This paper presents a new nonlinear adaptive control system for Uninterruptible Power Supply (UPS) systems. The proposed control system effectively isolates the double frequency ripple from the battery in the normal mode as well as the backup mode of operation. The proposed system is well-suited for UPSs with Lithium-Ion batteries, where the current ripple has to be very limited. Simulation and experimental results verify the feasibility of the proposed control system and demonstrate its superior performance.