Power quality improvement and uninterruptible power supply using a power conditioning system with energy storage capability

A power conditioning system with energy storage capability is proposed as a viable solution for improving the quality and the reliability of the electric energy supply. Several tasks can be performed at the same time, such as reactive power compensation, current harmonic reduction, and smoothing of pulsating loads. Moreover, the power conditioning system can operate as an uninterruptible power supply during short time interruptions of the grid supply. The proposed system is a flexible structure that can be coupled to several energy storage devices like batteries, flywheels, supercapacitors, superconductive magnetic energy storage systems. In order to show the power conditioning system performance, experimental tests have been carried out using a flywheel as storage device. The effectiveness of the proposed control system has been successfully verified in several operating conditions of the grid supply and of the load.