Design of a linear Halbach magnetic damper

摘要

Ultra-fast circuit breakers are operated with fast electromagnetic actuators. They can generate a sufficient impulse force to swiftly open electrical contacts in a couple of milliseconds. Opening of the contacts with high velocities implies a need for a timely and controllable damping. An efficient damping mechanism then is crucial to attain an appropriate actuation performance and secure a long lifetime. In this paper a finite element model of a Halbach magnet array based magnetic damper and a corresponding experimental prototype is described. A parametric study is performed to understand the effect of load mass and incoming velocities. It was found that the magnetic field modulation plays an important role on the damping performance. A uniform and high radial component of the magnetic flux density is necessary in order to achieve high damping force. The radial magnetic field can be controlled via thickness and magnetization direction of the ring magnets that are used to create the Halbach magnet array.