Modelling of a flywheel energy storage system with load following, energy time-shifting, and photovoltaic power smoothing capabilities

Power systems with renewable energy resources have issues with reliability while energy demands are increasing. The flywheel energy storage system can improve the power quality and reliability of renewable energy. In this study, a model of the system was made in Matlab – Simulink for load-following, energy time-shifting, and photovoltaic power smoothing applications. The model can reflect the actual behavior of a flywheel based on the M32 flywheel design of Amber Kinetics. Two program flows were designed for separating load following and energy time-shifting application from the power smoothing application. Consequently, the model can perform the two applications individually. Subsystems for a photovoltaic array, load, grid, and inverter are also present in the model. Results show that the load following, and energy time-shifting applications of the model can match the grid with an efficiency of 86% and has stored energy for the next day leaving 25% to 45% state of charge in a 48-hr simulation, thus, diminishing dependencies on the grid. Moreover, the result of the power smoothing simulation demonstrates that the flywheel creates softer slopes with minimal fluctuations than the photovoltaic array alone.