Performance characteristics of an HTS linear synchronous motor with HTS bulk magnet secondary

A single-sided high-temperature superconducting (HTS) linear synchronous motor (HTSLSM) with an HTS bulk magnet array as its secondary has been developed, and a split pulse coil magnetization system is used to magnetize the secondary HTS bulks with alternating magnetic poles. The electromagnetic parameters of the HTSLSM have been calculated to verify its performance. The HTSLSM is incorporated with a developed control system based on the voltage space vector pulsewidth modulation strategy implemented by a computer-software-controlled platform. A compositive experimental testing system has also been developed to measure the thrust and normal force of the HTSLSM. The traits of the thrust and normal force have been comprehensively identified experimentally, and the results from the experiments and analysis would benefit the electromagnetic design and the control scheme development for the HTSLSM. © 2006 IEEE

Power electronic-controlled high Q resonator theory with HTS technology

Power electronic-controlled switch has been used with a high-temperature superconductor (HTS) to develop an advanced high Q resonant circuit. With a HTS, a very high Q circuit can be achieved; consequently special aspects such as high voltage generation can be theoretically and practically realized. Theoretical study has been carried out for this concept and method, and this paper describes the theory of this high Q resonant circuit and the operational principle. © 2006 IEEE

HTS high Q resonant controller

High Tc superconductor (HTS) technology has been used to develop an advanced high Q resonant circuit and its devices. With a HTS, a very high Q circuit can be achieved; consequently special aspects such as high voltage generation and high current control can be theoretically and practically realized. Theoretical study has been carried out, as well as a practical approach has been made for the concept verification. This paper describes the theory of this high Q resonant circuit and the operational principle of its high voltage generation and current control

Performance analysis of a linear motor with HTS bulk magnets for driving a prototype HTS maglev vehicle

This paper presents the performance analysis of a linear synchronous motor which employs high-temperature superconducting (HTS) bulk magnets on the mover and normal copper windings on the stator. The linear motor is designed to drive a prototype HTS maglev vehicle in which the mover is suspended by the levitation force between HTS bulks on the mover and permanent magnets on the ground. Finite element magnetic field analysis is conducted to calculate the major parameters of the linear motor and an equation is derived to calculate the electromagnetic thrust force. Theoretical calculations are verified by the measured results on the prototype. © (2013) Trans Tech Publications, Switzerland

Measurement and modeling of rotational core losses of soft magnetic materials used in electrical machines: A review

In many situations, for example, in the cores of a rotating electrical machine and the T-joints of multiphase transformers, the magnetic flux varies with time in terms of both magnitude and direction, i.e., the local flux density vector rotates with varying magnitude and varying speed. Therefore, it is important that the magnetic properties of the core materials under various rotational magnetizations be properly investigated, modeled, and applied in the design and analysis of electromagnetic devices with rotational flux. Drawing from the huge amount of papers published by various researchers in the past century, this paper presents an extensive survey on the measurement and modeling of rotational core losses of soft magnetic materials used in electrical machines, particularly from the view of practical engineering application. The paper aims to provide a broad picture of the historical development of measuring techniques, measuring apparatus, and practical models of rotational core losses. © 2008 IEEE

Medium-frequency-link power conversion for high power density renewable energy systems

Recent advances in solid-state semiconductors and magnetic materials have provided the impetus for medium frequency-link based medium voltage power conversion systems, which would be a possible solution to reducing the weight and volume of renewable power generation systems. To verify this new concept, in this paper, a laboratory prototype of 1.73 kVA medium-frequency-link power conversion system is developed for a scaled down 1 kV grid applications. The design and implementation of the prototyping, test platform, and the experimental results are analyzed and discussed. It is expected that the proposed new technology would have great potential for future renewable and smart grid applications. © 2013 IEEE

B-H relations of magnetorheological fluid under 2-D rotating magnetic field excitation

This paper presents the investigation of the B-H relations of a magnetorheological (MR) fluid under one-dimensional (1-D) alternating and two-dimensional (2-D) rotating magnetic field excitations where B is magnetic flux density and H is magnetic field strength. The measurement is carried out by using a single sheet tester with an MR fluid sample. The measurement principle and structure of the testing system are described. The calibration of the B and H sensing coils are also reported. The relations between B and H on the MR fluid sample under 2-D rotating magnetic field excitations have been measured and compared with the results under 1-D excitations showing that the B-H relations under 2-D excitations are significantly different from the 1-D case. These data would be useful for design and analysis of MR smart structures like MR dampers. © 2013 IEEE

Optimization of a five-phase E-core bearingless flux-switching permanent magnet motor for flywheel batteries

© 2018 IEEE. In this paper, a five-phase E-core bearingless fluxswitching permanent magnet (BSFPM) motor for flywheel batteries is proposed and optimized. First, the structure and the principle of the BSFPM motor are described simply. Second, the trial and error method is used to obtain the most reasonable relationship of center tooth arc width and edge tooth arc width, and then the electromagnetic torque and suspension force after optimization are got. The motor after optimization has smoother five-phase flux-linkage and the disturbance of the torque and suspension force decrease

Experimental studies of strong dipolar interparticle interaction in monodisperse Fe3O4 nanoparticles

Interparticle interaction of monodisperse Fe3 O4 nanoparticles has been experimentally investigated by dispersing the nanoparticles in solvents. With increasing the interparticle distances to larger than 100 nm in a controlled manner, the authors found that the blocking temperature (TB) of the nanoparticles drops continuously and eventually gets saturated with a total drop in TB of 7-17 K observed for 3, 5, and 7 nm samples, compared with their respective nanopowder samples. By carefully studying the dependence of TB on the interparticle distance, the authors could demonstrate that the experimental dependence of TB follows the theoretical curve of the dipole-dipole interaction. © 2007 American Institute of Physics.open313

Attenuation of leukocyte sequestration by selective blockade of PECAM-1 or VCAM-1 in murine endotoxemia

Background: Molecular mechanisms regulating leukocyte sequestration into the tissue during endotoxemia and/or sepsis are still poorly understood. This in vivo study investigates the biological role of murine PECAM-1 and VCAM-1 for leukocyte sequestration into the lung, liver and striated skin muscle. Methods: Male BALB/c mice were injected intravenously with murine PECAM-1 IgG chimera or monoclonal antibody (mAb) to VCAM-1 ( 3 mg/kg body weight); controls received equivalent doses of IgG2a ( n = 6 per group). Fifteen minutes thereafter, 2 mg/kg body weight of Salmonella abortus equi endotoxin was injected intravenously. At 24 h after the endotoxin challenge, lungs, livers and striated muscle of skin were analyzed for their myeloperoxidase activity. To monitor intravital leukocyte-endothelial cell interactions, fluorescence videomicroscopy was performed in the skin fold chamber model of the BALB/c mouse at 3, 8 and 24 h after injection of endotoxin. Results: Myeloperoxidase activity at 24 h after the endotoxin challenge in lungs (12,171 +/- 2,357 mU/g tissue), livers ( 2,204 +/- 238 mU/g) and striated muscle of the skin ( 1,161 +/- 110 mU/g) was significantly reduced in both treatment groups as compared to controls, with strongest attenuation in the PECAM-1 IgG treatment group. Arteriolar leukocyte sticking at 3 h after endotoxin (230 +/- 46 cells x mm(-2)) was significantly reduced in both treatment groups. Leukocyte sticking in postcapillary venules at 8 h after endotoxin ( 343 +/- 69 cells/mm(2)) was found reduced only in the VCAM-1-mAb-treated animals ( 215 +/- 53 cells/mm(2)), while it was enhanced in animals treated with PECAM-1 IgG ( 572 +/- 126 cells/mm(2)). Conclusion: These data show that both PECAM-1 and VCAM-1 are involved in endotoxin-induced leukocyte sequestration in the lung, liver and muscle, presumably through interference with arteriolar and/or venular leukocyte sticking. Copyright (C) 2004 S. Karger AG, Basel