Dynamic performance improvement of a hybrid multimachine system using a flywheel energy storage system

This article presents a detailed, yet simple control scheme based on a flywheel energy storage system for dynamic performance enhancement. A permanent magnet machine-based 70 MW flywheel energy storage system is incorporated in a wind-integrated Western System Coordinating Council multimachine system. An elaborate mathematical modelling of the flywheel energy storage system as an effective current source is provided along with the wind-embedded multimachine system to investigate the transient stability profile of the said system. Generator speed and voltage are continuously monitored by the flywheel energy storage system plant controllers, and subsequent real and reactive reference power commands are generated. Two first-order lag blocks are employed to emulate the grid side and machine side converters' dynamics. The developed non-linear model is tested against three-phase faults in a variable wind condition, and the effectiveness of the control scheme is confirmed by the enormous damping and extension in the stability margin of the system.