Segmented rim design for high performance flywheel energy storage system

Flywheel energy storage systems are widely used in short-duration applications such as grid stabilization, frequency regulation, and uninterruptible power supply because of their high power density, fast response, and long operational life. However, broadening their role to include applications requiring both high power and increased energy capacity demands a fundamental redesign of the rotor. Conventional single-material flywheels—metallic or composite—remain limited by stress constraints and inefficient material utilization. Advanced press-fitted multi-rim composite designs improve energy density and capacity but suffer from circumferential stress accumulation, rim detachment, and manufacturing complexity. This paper introduces the Segmented Rim Flywheel concept, a novel architecture composed of thin composite rims separated by strategic gaps rather than interference fits. This configuration reduces radial and axial tensile stress, eliminates interfacial failure risk, and fully exploits the circumferential strength of composite materials. Comparative analysis confirms the design’s superior performance in terms of energy storage capacity, positioning it as a promising solution for next-generation flywheel systems aimed at both peak shaving and higher-capacity storage needs.