Optimized Realization of Fault-Tolerant Heteropolar Magnetic Bearings
نویسندگان
چکیده
Flux coupling in heteropolar magnetic bearings permits remaining active coils to assume actions of failed coils to produce force resultants identical to the un-failed actuator. This fault-tolerant control usually reduces load capacity because the redistribution of the magnetic flux which compensates for the failed coils leads to premature saturation in the stator or journal. A distribution matrix of voltages which consists of a redefined biasing voltage vector and two control voltage vectors can be optimized in a manner that reduces the peak flux density. An elegant optimization method using the Lagrange multiplier is presented in this paper. The linearized control forces can be realized up to certain combination of 5 poles failed for the 8 pole magnetic bearing. Position stiffness and voltage stiffness are calculated for the fault-tolerant magnetic bearings. Simulations show that fault-tolerant control of the multiple poles failed magnetic bearings with a horizontal flexible rotor can be achieved with reduced load capacity. @S0739-3717~00!01103-X#
منابع مشابه
Bearing Fault Detection Based on Maximum Likelihood Estimation and Optimized ANN Using the Bees Algorithm
Rotating machinery is the most common machinery in industry. The root of the faults in rotating machinery is often faulty rolling element bearings. This paper presents a technique using optimized artificial neural network by the Bees Algorithm for automated diagnosis of localized faults in rolling element bearings. The inputs of this technique are a number of features (maximum likelihood estima...
متن کاملAN INTELLIGENT FAULT DIAGNOSIS APPROACH FOR GEARS AND BEARINGS BASED ON WAVELET TRANSFORM AS A PREPROCESSOR AND ARTIFICIAL NEURAL NETWORKS
In this paper, a fault diagnosis system based on discrete wavelet transform (DWT) and artificial neural networks (ANNs) is designed to diagnose different types of fault in gears and bearings. DWT is an advanced signal-processing technique for fault detection and identification. Five features of wavelet transform RMS, crest factor, kurtosis, standard deviation and skewness of discrete wavelet co...
متن کاملPrediction of rotating losses in heteropolar radial magnetic bearings
Previously, thin plate assumptions have been used to obtain a one-dimensional eddy current model for predicting the stationary, transformer-type losses in magnetic bearings built out of laminated material. Using similar assumptions as in the 1-D eddy current model, rotating losses can be predicted for a laminated heteropolar radial magnetic bearing. The thin plate model of rotating losses yield...
متن کاملA Generalized Unbiased Control Strategy for Radial Magnetic Bearings
Abstract: The present work extends a method of unbiased control originally developed for three-pole radial magnetic bearings into a generalized unbiased control strategy that encompasses bearings with an arbitrary number of poles. By allowing the control of bearings with more than three poles, the applicability of the approach is broadened to the case of large rotors. Other ramifications of thi...
متن کاملTitle: Influence of actuator geometry on rotating losses in heteropolar magnetic bearings
Recently, work on rotating losses in magnetic bearings has focused mainly on the measurement of rotating losses, and on the creation of models that attempt to reproduce these results. Though there has been some success on both counts, there has been less emphasis on interpreting what these results mean in terms of practical guidelines for the design of low-loss bearings. The present work reform...
متن کامل