Design, Modeling and Control of Magnetic Bearings for a Ring-Type Flywheel Energy Storage System

Abstract

This study is concerned with the magnetic force models of magnetic bearing in a flywheel energy storage system (FESS). The magnetic bearing is of hybrid type, with axial passive magnetic bearing (PMB) and radial hybrid magnetic bearing (HMB). For the PMB, a pair of ring-type Halbach arrays of permanent magnets are arranged vertically to support the rotor weight. For the HMB, a set of ring-type Halbach array is placed on the rotor side, which corresponds to coil sets on the stator side. The HMB can produce both attraction and repulsion forces on the radial direction, depending on the direction of the coil currents. It is found that the ring-type configuration and the differential winding scheme for coil sets can yield linear magnetic force models for both PMB and HMB. Based on the obtained magnetic force model, an integral sliding mode controller is designed for the stable rotor levitation in the radial direction. The experimental results show that the rotor can be stabilized to the bearing center, verifying the accuracy of the magnetic force models and effectiveness of the levitation controller.

Optimization of the Guiding Stability of a Horizontal Axis HTS ZFC Radial Levitation Bearing

“…A process to control the displacement and speed of a motor with two radial levitations and one axial thrust magnetic bearing was described in [14]. The generation of compensation forces to actively control the displacement of a flywheel with passive and hybrid magnetic bearings is described in [15].…”

Effects of Imperfect Assembly and Magnetic Properties on the Three-Pole AMB System

“…It can also be applied in extreme environments, such as very high or low pressure, very high or low temperature, vacuum, and zero gravity. Because of these features, AMB has found wide applications, for instance, in turbo-molecular pumps [2], high-speed air compressor [3,4], flywheel energy-storage systems [5,6], control-momentum wheels [7], printed electronics systems [8], and machine tools [9], etc.…”

Design and Modeling of an Integrated Flywheel Magnetic Suspension for Kinetic Energy Storage Systems

“…In [14], two sets of axial PMB are used for the vertical suspension, whereas two sets of radial hybrid MB actively control the rotor at the bearing center. The major benefit is that the energy consumption for levitation is eliminated, limiting at the same time the PM amount by using Halbach magnetized arrays.…”