A practical magnetic flux density observer for hybrid suspension system of maglev train

Abstract

The purpose of this paper is to design a practical flux density observer which provides the accurate magnetic flux density signal for the flux feedback control of electromagnet-permanent magnet (EM-PM) hybrid suspension system in maglev train. Firstly, the property of two basic kinds of flux observers based on current model and voltage model are discussed. To improve the design of the observed flux density, a practical observer is raised by extracting the low frequency flux density signal from current model and high frequency flux density signal from voltage model. Further more, based on the analysis of error source of the flux observer, the parameter self-tuning scheme using model reference adaptive system (MRAS) and the track irregularity estimation are applied in it for the purpose of higher accuracy. And then, based on the suspension module, the numerical comparisons and related experiments are carried out. Results show that the raised observer can get satisfied signal for the control in suspension system. And the closed loop control system with observed flux feedback can achieve satisfied performance.