scholarly journals A Dual-Loop Control Approach of Active Magnetic Bearing System for Rotor Tracking Control

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 121760-121768
Author(s):  
Xuan Yao ◽  
Zhaobo Chen ◽  
Yinghou Jiao
Keyword(s):  
Tracking Control ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Loop Control ◽  
Control Approach ◽  
Bearing System

Destabilization of Forward Rub in Rotor Magnetic Bearing Systems Using Actively Controlled Auxiliary Bearings

2010 ◽  
Author(s):  
Iain S. Cade ◽  
M. Necip Sahinkaya ◽  
Clifford R. Burrows ◽  
Patrick S. Keogh
Keyword(s):  
Design Feature ◽  
Magnetic Bearing ◽  
Open Loop ◽  
Active Magnetic Bearing ◽  
Loop Control ◽  
Bending Mode ◽  
Operating Limits ◽  
Auxiliary Bearing ◽  
Contact Free ◽  
Bearing System

During fault conditions, rotor displacements in magnetic bearing systems may potentially exceed safety/operating limits. Hence it is a common design feature to incorporate auxiliary bearings adjacent to the magnetic bearings for the prevention of rotor/stator contact. During fault conditions the rotor may come into contact with the auxiliary bearings, which may lead to continuous rub type orbit responses. In particular, forward rub responses may become persistent. This paper advances the methodology by considering an actively controlled auxiliary bearing system. An open-loop control strategy is adopted to provide auxiliary bearing displacements that destabilize established forward rub orbit responses. A theoretical approach is undertaken to identify auxiliary bearing motion limits at which forward rub responses become unstable. Experimental validation is then undertaken using a rotor/active magnetic bearing system with an actively controlled auxiliary bearing system under piezoelectric actuation. Two different operating speeds below the first bending mode of the rotor are considered and the applied harmonic displacements of the auxiliary bearing are shown to be effective in restoring contact free levitation.

scholarly journals Development and Experimental Validation of Auxiliary Rolling Bearing Models for Active Magnetic Bearings (AMBs) Applications

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Anna Tangredi ◽  
Enrico Meli ◽  
Andrea Rindi ◽  
Alessandro Ridolfi ◽  
Pierluca D’Adamio ◽  
...  
Keyword(s):  
Load Capacity ◽  
Critical Phenomenon ◽  
Magnetic Bearing ◽  
Design Tool ◽  
Magnetic Bearings ◽  
Active Magnetic Bearing ◽  
Active Magnetic Bearings ◽  
Short Period ◽  
Auxiliary Bearing ◽  
Bearing System

Nowadays, the search for increasing performances in turbomachinery applications has led to a growing utilization of active magnetic bearings (AMBs), which can bring a series of advantages thanks to their features: AMBs allow the machine components to reach higher peripheral speeds; in fact there are no wear and lubrication problems as the contact between bearing surfaces is absent. Furthermore, AMBs characteristic parameters can be controlled via software, optimizing machine dynamics performances. However, active magnetic bearings present some peculiarities, as they have lower load capacity than the most commonly used rolling and hydrodynamic bearings, and they need an energy source; for these reasons, in case of AMBs overload or breakdown, an auxiliary bearing system is required to support the rotor during such landing events. During the turbomachine design process, it is fundamental to appropriately choose the auxiliary bearing type and characteristics, because such components have to resist to the rotor impact; so, a supporting design tool based on accurate and efficient models of auxiliary bearings is very useful for the design integration of the Active Magnetic Bearing System into the machine. This paper presents an innovative model to accurately describe the mechanical behavior of a complete rotor-dynamic system composed of a rotor equipped with two auxiliary rolling bearings. The model, developed and experimentally validated in collaboration with Baker Hughes a GE company (providing the test case and the experimental data), is able to reproduce the key physical phenomena experimentally observed; in particular, the most critical phenomenon noted during repeated experimental combined landing tests is the rotor forward whirl, which occurs in case of high friction conditions and greatly influences the whole system behavior. In order to carefully study some special phenomena like rotor coast down on landing bearings (which requires long period of time to evolve and involves many bodies and degrees of freedom) or other particular events like impacts (which occur in a short period of time), a compromise between accuracy of the results and numerical efficiency has been pursued. Some of the elements of the proposed model have been previously introduced in literature; however the present work proposes some new features of interest. For example, the lateral and the axial models have been properly coupled in order to correctly reproduce the effects observed during the experimental tests and a very important system element, the landing bearing compliant suspension, has been properly modelled to more accurately describe its elastic and damping effects on the system. Furthermore, the model is also useful to characterize the frequencies related to the rotor forward whirl motion.

Integral Sliding Mode Control Approach for 3-Pole Active Magnetic Bearing System

2016 ◽  
Vol 829 ◽  
pp. 128-132 ◽  
Author(s):  
Van Van Huynh ◽  
Minh Hoang Quang Tran
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Sliding Surface ◽  
Integral Sliding Mode Control ◽  
Integral Sliding Mode ◽  
Mode Control ◽  
Integral Sliding Surface ◽  
Bearing System

In this paper, a new integral sliding mode control scheme is designed for the 3-pole active magnetic bearing system. First, a new integral sliding surface is designed such that the 3-pole active magnetic bearing system in the sliding mode is asymptotically stable under certain conditions. Then, an adaptive controller is designed to solve the unknown upper bound of matched uncertainty and guarantee the reachability of the integral sliding surface. Finally, the performance of the proposed integral sliding mode controller is applied to 3-pole active magnetic bearing system to demonstrate the efficacy of the proposed method.

Sign in / Sign up

Export Citation Format

Share Document