The high temperature superconducting (HTS) bulk needs to work in a LN 2 environment for long time. Under the action of applied alternating magnetic field, flux movement HTS induces AC loss system, which leads rise effect bulk, and will affect stability system. A majority previous research focused on ideal bulks, few researches have been done characteristics superconductors with defects. In this paper, non-ideal fillet defect is considered, two-dimensional partial differential equation...

A fiber Bragg grating (FBG) pressure sensor using a composite structure comprising square diaphragm, steel trusses, and vertical beams is proposed studied. The deflection of the diaphragm due to applied transferred as an axial force on FBG mounted at end beams. Measurement principle stress analysis are introduced. experimental results indicate that sensitivity 622.71 pm / MPa across range 0 2 with good linearity recorded 99.996%, hysteresis repeatability calculated be 0.6639% full-scale...

Abstract The purpose of this study is to discuss the effect defects on mechanical properties halbach-type guideway surfaces in high-temperature superconducting permanent magnetic levitation systems with single-surface superconductor distribution versus multi-surface distribution. models system based Maxwell’s equations and compares it experimental data obtain variation curve force under ideal conditions. Through numerical simulation analysis, found that guiding will regularly decrease...

Dynamic behavior with the hysteresis of levitation force a high temperature magnet-superconductor system is investigated application displacement harmonic excitation. The dynamic characteristics transient stage and steady forced vibration are discussed in detail. period-doubling natural frequency components found vibration. It means that initial frozen magnetic field superconductor plays an important role on response. amplitude vs. excitation presented. A transition triple given to...

In order to make the permanent magnet synchronous motor control system has a good dynamic performance and robustness, this paper introduces design of decoupling controller realize that. We used an inverse method in control, analysis mathematics model d-q synchronization reference frame, put forward analytical expressions motor. Simulation results show that realized speed torque decoupling, had static robustness. This with methods successfully applies thus

The equilibrium height (EH) of a levitated permanent magnet (PM) is investigated in an oscillation system composed the PM and high temperature superconductor (HTS). Two kinds initial quasi-static magnetization processes are performed respectively, then EH achieved aft er damped vibration PM. A peak value EH, associated with transitional (TMH), found for first process. When (MH) less than TMH, increases increasing MH nonlinearly. Otherwise decreases linearly MH. For second process minimum...

In this paper we present the dependence of maximum levitation force (FzMax) a high-Tc superconductor on surface magnetic field (Bs) cylindrical permanent magnet, based Bean critical state model and Ampere's law. A transition point Bs is found at which relation between FzMax changes: while less than subjected to nonlinear function, otherwise it linear one. The two different relations are estimated correspond partial penetration shielding currents in interior below complete above it,...

This paper investigates the adaptive fault tolerant consensus control (FTC) problem based on neural networks for nonlinear multi-agent systems with actuator faults. Adaptive technique RBF network is proposed to achieve asymptotic results of system. Respectively, all signals resulting closed loop system are bounded by using Lyapunov stability theorem and distributed robust scheme. Finally, a simulation example demonstrated show effectiveness strategies.

A quadratic approximation method for the limit value of magnetic stiffness in a high temperature superconducting levitation system is presented. The configuration discussed that cylindrical permanent magnet (PM) placed above coaxial superconductor (HTS). force between PM and HTS gained based on Kim's critical model Ampère circulation theorem. central issue associated with hysteresis discussed. Firstly, To given gap HTS, approximate values obtained corresponding to different displacement...

Magnetic stiffness is one of the important stability parameters high temperature superconducting levitation systems. Till to now, great efforts have been made understand properties including flux penetration, magnetization curves, force, ac susceptibilities, etc. In this paper we present a quadratic approximation method for limit magnetic in system based on Kim’s critical state model and Ampère law. The composed with cylindrical permanent magnet (PM) coaxial superconductor (HTS). It found...

The eigenvalue analysis of nonproportionally damped structures has received much recent attention, as most the algorithms to solve undamped problems do not directly extend case. In many cases, one is only interested in finding eigenvalues that lie a region complex plane. this presentation, we propose an algorithm exploits fact. begins by problem and tracks damping gradually added. For each increment damping, new estimates are obtained forcing structure at previous eigenpair using forced...

Based on Kirchhoff's current law, this paper calculated and analyzed a fault that the shunt capacitor of generator circuit breaker phase loss. The reasons causing abnormal condition outlet voltage low side main transformer are analyzed. It is concluded may cause imbalance capacitance to earth each system, thus lead system. And basis, combined with author's work experience, give preventive measures for such situations reference.

The characteristics of backfill loess is different from undisturbed loess. Researches on pile foundations large thickness sites are relatively scarce. Based a Q4 site, with the depth 25 m, concrete strain gauges and reinforcement stress meter were arranged shafts, soil pressure cells installed bottom for field load test three piles. Results show that: in layer, piletop proportional to negative skin friction, inversely time occurrence positive friction. ratio neutral point (Neutral...