Recently, the Inner Mongolia Autonomous Region’s major scientific and technological project “MW-level Advanced Flywheel Energy Storage Key Technology Research,” undertaken by Beijing Honghui International Energy Technology Development Co., Ltd. (hereinafter referred to as “Honghui Energy”) in collaboration with China Nuclear Huineng Co., Ltd. and other units, successfully connected a single MW-level flywheel energy storage array to the grid.

The project involves the application of frequency regulation in new energy stations using a “Flywheel Energy Storage + Lithium Battery Hybrid Energy Storage” system. Three MW-level flywheel arrays are controlled in coordination with a 3MW lithium-ion battery to form a hybrid energy storage system, which has been successfully integrated into the 99MW Erenhot Wind Farm, providing frequency regulation services. Through the long-term operation of the hybrid energy storage system on the grid, the project explores the collaborative operation of flywheels, batteries, and wind farms to meet the primary frequency regulation requirements, seeking the most economical solution for wind farms’ primary frequency regulation, which has significant demonstration significance.

Flywheel energy storage is a physical energy storage technology that converts electrical energy into kinetic energy and vice versa. It features instantaneous high power, millisecond-level response time, millions of charge-discharge cycles, no degradation throughout its lifecycle, and an ultra-long lifespan of over 20 years. These characteristics perfectly match the charge-discharge conditions required for primary frequency regulation. When combined with electrochemical systems in a hybrid energy storage system, the advantages complement each other. The flywheel handles high-frequency charge-discharge conditions, improving the electrochemical system’s safety and stability while extending its lifespan. In novel power systems, this system can provide active power support and inertia support, widely used for primary frequency regulation, AGC, inertia support, and other ancillary services in power systems.