High efficient permanent magnet actuator design by mitigating irreversible demagnetization effect

This paper proposed a new design method for high efficient permanent magnet actuator with considering the irreversible demagnetization of magnet. The nonlinear B-H characteristic of magnet, which is determined by the driving temperature and the reactive magnetic field strength, is applied to predict the magnetic performance of the actuator in a practical driving condition. The optimization problem is formulated to minimize the demagnetized magnet area at the load state while the target magnetic performance is achieved. To obtain the clear boundaries of optimal magnet distribution, a level set function is employed as the topological design variable. An actuator design example will show the usefulness of the proposed method and a way to reduce the permanent damage of magnet.