Design of reaction flywheel systems for small satellites

According to the requirement of reaction flywheels in small satellites for small sizes, the design method for an armature size was proposed when the electrical motor was at a minimal volume, and a stator coreless reaction flywheel system was designed based on the method. To avoid the magnetic saturation, the multidisciplinary design optimization method was applied to the design of flywheel rotor and magnetic field of the motor. A optimization strategy combined with Exterior Penalty(EP) function and Sequential Quadratic Programming(SQP) was proposed to optimize the system as well. With optimization, the minimum mass and maximum air-gap magnetic flux density of the rotor were chosen as the objects, respectively, and the maximum equivalent stress, resonance frequency, the polar moment of inertia and the magnetic saturation were taken as constrains. Then, the software iSIGHT with finite element analysis (ANSYS) were integrated to achieve the optimization. Finally, a flywheel prototype was designed based on the optimal results. The results indicate that the total mass of the flywheel rotor has been decreased from 0.73 kg to 0.67 kg (reduced by 8.22%) and the flux density has been increased from 0.376 T to 0.401 T (increased by 6.65%). The optimal design method can improve the rationality of flywheel design, and will promote the progress of the miniaturization investigation of flywheel systems.