Unbalanced voltage drops compensations using flywheel energy storage system

Abstract

A novel flywheel energy storage system is proposed in this study. The energy storage system consists of a flywheel coupled to permanent magnets synchronous machine. The stored energy is used for an unbalanced drop correction for the critical load using Three-Leg Four-Wire Converter. In motoring mode (no drop on the grid), the grid connected converter lets the system deliver power and boosts the DC link voltage until the flywheel reaches the maximum speed. In generating mode, the grid connected converter supplies sinusoidal voltage to the grid. The permanent magnets synchronous machine is selected for the design of a three-phase machine for the flywheel energy storage system and space vector modulation is used for controlling both converters.