Flywheel

ISO 21648:2008 establishes the design, analysis, material selection and characterization, fabrication, test and inspection of the flywheel module (FM) in a flywheel used for energy storage in space systems. These requirements, when implemented on a flywheel module, will ensure a high level of confidence in achieving safe operation and mission success. With appropriate modifications, ISO 21648:2008 can also be applied to similar devices, such as momentum and reaction wheels and control-moment gyroscopes. The requirements set forth in ISO 21648:2008 are the minimum requirements for flywheel modules in flywheels used in space flight applications. They are specifically applicable to the parts in the flywheel rotor assembly (FRA), including rim, hub and/or shaft and other associated rotating parts, such as the bearings and the motor generator rotor. The requirements are also relevant to the non-rotating parts, such as module housing, main suspension assembly (magnetic or rolling element bearings, superconductor bearings, etc.), motor stator, caging mechanism and sensors within the module housing, and backup bearings, if applicable. However, control and interface electronics are not covered in ISO 21648:2008.

Recommended information for an objective evaluation of an emerging or alternative energy storage device or system by a potential user for any stationary application is covered in this document. Energy storage technologies are those that provide a means for the reversible storage of electrical energy, i.e., the device receives electrical energy and is able to discharge electrical energy at a later time. The storage medium may be electrochemical (e.g., batteries), kinetic (e.g., flywheels), electrostatic (e.g., electric double-layer capacitors), thermal, compressed air, or some other medium. Devices recharged by non-electrical means, such as fuel cells, are beyond the scope of this document. The document provides a common basis for the expression of performance characteristics and the treatment of life-testing data. A standard approach for analysis of failure modes is also provided, including assessment of safety attributes. The intent of this document is to ensure that characterization information, including test conditions and limits of applicability, is sufficiently complete to allow valid comparisons to be made.