Simulation analysis of multi-ring interference assembly of large capacity composite flywheel rotor

The large-capacity power flywheel energy storage system serves as a high-quality frequency modulation resource for the power system. Utilizing high-strength, low-density composite materials in the manufacture of flywheel rotors is a primary method for enhancing flywheel energy storage. In this paper, we focus on the large-size multi-ring composite flywheel rotor. Based on the elastic theory, the stress distribution formula of the anisotropic material rotor rim under high-speed rotation is derived. Based on the stress superposition principle, the stress analysis formula under the interference fit of the composite rim and the metal hub is obtained, and the analytical solution is given. Based on the radial displacement of each ring, a suitable amount of interference is determined. Subsequently, a finite element analysis model for the interference fit between the composite rim and the metal hub is established. The stress distribution of the rotor is simulated and analyzed. The simulation results are basically consistent with the analytical results, which verifies the rationality of the model. Finally, we analyze and compare the difference between multi-ring isomorphism and multi-ring isomerism, and then the applicability of the analytical solution and simulation solution to the stress distribution of three-ring and four-ring composite flywheel rotor is further verified. The results demonstrate that, for large-size composite flywheels, existing formula analysis calculations and finite element simulation calculations align, highlighting a need for experimental verification in future research.