Wenfei Tao¹, Chen Chen¹

Revista Internacional de Métodos Numéricos para Cálculo y Diseño en Ingeniería, Vol.39, No.4, pp. 1-6, 2023, DOI:10.23967/j.rimni.2023.10.006 - 08 November 2023

Abstract Eddy current displacement sensors in full-maglev left ventricular assist devices (LVADs) suffer from low sensitivity resulting from the use of a stator titanium alloy frame. The aim of this study was to develop a methodology to improve the sensitivity of eddy current displacement sensors and formulate a mathematical model of coil impendence to illustrate the impact of the addition of a titanium alloy frame between the sensor coils and the measured conductor. An equivalent mutual inductance model in the circuit was established for LVADs with and without a titanium alloy frame stator wall. Comparing the… More >

Tinnawat Hongphan¹, Matthew O. T. Cole^1,*, Chakkapong Chamroon¹, Ziv Brand²

Energy Engineering, Vol.120, No.1, pp. 147-161, 2023, DOI:10.32604/ee.2022.022821 - 27 October 2022

Abstract This paper presents a theoretical and experimental study on controller design for the AMBs in a small-scale flywheel energy storage system, where the main goals are to achieve low energy consumption and improved rotordynamic stability. A H-infinity optimal control synthesis procedure is defined for the permanent-magnet-biased AMB-rotor system with 4 degrees of freedom. Through the choice of design weighting functions, notch filter characteristics are incorporated within the controller to reduce AMB current components caused by rotor vibration at the synchronous frequency and higher harmonics. Experimental tests are used to validate the controller design methodology and More >

Wei-Lung Mao^1,*, Yu-Ying Chiu¹, Chao-Ting Chu², Bing-Hong Lin¹, Jian-Jie Hung³

Intelligent Automation & Soft Computing, Vol.32, No.2, pp. 923-936, 2022, DOI:10.32604/iasc.2022.019555 - 17 November 2021

Abstract Electromagnets are commonly used as support for machine components and parts in magnetic bearing systems (MBSs). Compared with conventional mechanical bearings, the magnetic bearings have less noise, friction, and vibration, but the magnetic force has a highly nonlinear relationship with the control current and the air gap. This research presents a dynamic sliding mode backstepping control (DSMBC) designed to track the height position of modeless vertical MBS. Because MBS is nonlinear with model uncertainty, the design of estimator should be able to solve the lumped uncertainty. The proposed DSMBC controller can not only stabilize the… More >