Stability control of permanent magnet and electromagnetic hybrid Halbach array electrodynamic suspension system

Abstract

Purpose The purpose of the paper is to study the stability control of permanent magnet (PM) and electromagnetic hybrid Halbach array electrodynamic suspension (EDS) system because of the poor suspension stability caused by the well-known under-damped nature of PM EDS system. The adjustment control is realized by PM and electromagnetic hybrid Halbach array, which is composed by winding active normal conductor coils on PM surface. Design/methodology/approach The three-dimensional (3-D) electromagnetic force analytical expression of PM and electromagnetic hybrid Halbach array EDS system for a nonmagnetic conductive plate is derived. And the accuracy of the derived equations is verified by a 3-D finite-element model (FEM). Basing on the 3-D levitation force expression, an acceleration feedback suspension controller is designed to suppress the vibration of PM EDS system, and the suspension stability of the system under the track and load disturbance was simulated and analyzed. Findings The 3-D electromagnetic force comparison of analytical model and FEM are in good agreement, which verifies the correctness of the analytical expression. The simulation results show that the acceleration feedback suspension controller can make the system have good suspension stability under the external disturbance. So it proved that the PM and electromagnetic hybrid Halbach array EDS system can overcome the poor suspension stability caused by the under-damped nature of PM EDS system through the designed acceleration feedback suspension controller. Originality/value This paper designed an acceleration feedback suspension controller to suppress the vibration of PM and electromagnetic hybrid Halbach array EDS system under external disturbance, basing on the derived levitation force analytical expression. And the simulation results show that the acceleration feedback suspension controller can make the system have good suspension stability under the external disturbance.

Structure Size Optimization and Magnetic Circuit Design of Permanent Magnet Levitation System Based on Halbach Array

“…In [13][14], the authors attempted to model the magnetic force between permanent magnets using the surface current hypothesis method, but its accuracy has not been verified by empirical data. In [15][16], the suction and repulsion models of Halbach arrays were developed to analyze the effects of the suspension gap and magnetic dimension parameters on magnetic force, respectively. In [17][18], a repulsive permanent magnetic levitation system has been designed using Halbach arrays, and mathematical models for the levitation forces of three sets of Halbach arrays have been derived.…”

Design and Analysis of Guidance Function of Permanent Magnet Electrodynamic Suspension

“…Although EDS systems are usually considered to be inherently stable, there are a variety of factors, including perturbations and track irregularity, that may lead to unstable responses [12]. Therefore, PM EDS is an under-damped, or even an undamped, system [13]. To address this issue, there are many research institutions and scholars focused on improving the stability of the maglev train.…”