Flywheel energy storage in parallel

A typical flywheel energy storage system, which includes a flywheel/rotor, an electric machine, bearings, and power electronics. Fig. 3. The Beacon Power Flywheel, which includes a composite rotor and an electric machine, is designed for frequency regulation.

The use of new materials and compact designs will increase the specific energy and energy density to make flywheels more competitive to batteries. Other opportunities are new applications in energy harvest, hybrid energy systems, and flywheel's secondary functionality apart from energy storage.

While many papers compare different ESS technologies, only a few research, studies design and control flywheel-based hybrid energy storage systems. Recently, Zhang et al. present a hybrid energy storage system based on compressed air energy storage and FESS.

Thanks to the unique advantages such as long life cycles, high power density, minimal environmental impact, and high power quality such as fast response and voltage stability, the flywheel/kinetic energy storage system (FESS) is gaining attention recently.

Arani et al. present the modeling and control of an induction machine-based flywheel energy storage system for frequency regulation after micro-grid islanding. Mir et al. present a nonlinear adaptive intelligent controller for a doubly-fed-induction machine-driven FESS.

Almost all the existing flywheel systems are designed for specific applications such as frequency regulation or UPS. They require specialized knowledge and techniques for manufacture, assembly, and maintenance, which prevents them from being produced in large quantities to reduce cost per unit.