Basic analysis and design of the permanent magnet hybrid type magnetic bearing for small-sized hydraulic generator

Exploitation of the renewable energy is expected one of the most effective expedient to reduce of green house gas emissions, principally CO₂. In this context, small-sized hydraulic power generation is considered one effective method because of its potential energy amount. However, mechanical bearing which support the rotor shaft causes rotational loss and durability limitation. For the purpose of upgrade performance of hydraulic generator, permanent magnet hybrid type magnetic bearing is proposed in this study. Stator is designed by finite element method magnetic field analysis in order to obtain stronger bearing force with same size stator diameter. In addition, simple experimental setup is manufactured with the object of measuring bearing force of proposed magnetic bearing. Moreover, in order to predict dynamic performance of the rotor, simulation was carried out by using measured bearing force stiffness and permanent magnet negative spring constant. Simulation result show high response performances.