Damper windings for the magnetic gear

Different design possibilities for passive suppression of transient oscillations in magnetic gears are investigated. Compared to their mechanical counterparts magnetic gears enjoy the advantage of having inherent overload capability, yet they suffer from a much lower torsional stiffness, resulting in long-lasting oscillations during transient changes in speed and load. Damper windings have long been used in synchronous generators to suppress oscillations due to transients, and are applied here to the magnetic gear for the same purpose. The effect of different design parameters such as location and number of bars, as well as their dimensions, and resistance of the end ring on the performance of damper windings is investigated. The possibility of inserting damper bars in the free space between the stator pole pieces is also inspected.