Single-phase induction motors have a wide range of domestic and industrial applications. These motors have a squirrel cage rotor and their stator usually has two windings: main and auxiliary. The use of auxiliary winding in the structure of single-phase induction motors creates two unbalance and asymmetric phases. This causes to increase the spatial harmonics of the field in the air gap, and al...

We study single-texture collapse using a leapfrog discretization method on a 30X30X30 spatial lattice. We investigate the influence of boundary conditions, physical size of the lattice, type of space-time background (flat, i.e., nonexpanding, vs radiation-dominated and matter-dominated universes), and spatial distribution of the initial texture configuration on collapse time and critical windin...

power system overvoltages due to switching, lightning and other disturbances are the main problem for designers of the power transformers. once some frequencies of the incoming surges match with some of the natural frequencies of transformer winding, the resonance phenomenon is expected in transformer winding. the resonant overvoltages may destroy the insulation between turns and cause to insul...

A 2D finite element electromagnetic model that permits the simulation of a cage induction machine, involving the effects of eddy currents and coupling the field equation with the stator fieldcircuit equation, has been presented in this paper. Transformation matrix has been derived to incorporate specialized stator winding scheme called the bridge configured winding (BCW) in the coupled field ci...

We consider a Lebwohl-Lasher model of chiral particles confined in a planar cell (slit pore) under different boundary conditions, and solve it using mean-field theory. The phase behaviour of the system with respect to temperature and pore width is studied. Two phenomena are observed: (i) an isotropic-cholesteric transition, which exhibits an oscillatory structure with respect to pore width, and...

An autonomous induction generator (IG) with an asymmetric configuration, in which both the stator and the rotor are single-phase, is often formed when a triple-phase wound rotor loses connection to a winding component while running. The machine still works and is shown to be capable of generating modulated waveforms. Equations can help as an IG design guideline. The first harmonics of the mutua...

Overvoltage distribution along the transformer winding must be uniform to certify the safety of the operation of the power transformer. Influence of the parameters variation on the impulse voltage distribution (IVD) in disk winding transformer is going to be analyzed which hasn’t been analyzed on this type of winding in the previous papers. In this research, a transformer with disk winding and ...

Power system overvoltages due to switching, lightning and other disturbances are the main problem for designers of the power transformers. Once some frequencies of the incoming surges match with some of the natural frequencies of transformer winding, the resonance phenomenon is expected in transformer winding. The resonant overvoltages may destroy the insulation between turns and cause to insul...

Abstract An asymmetric dependence of the critical current on direction an applied magnetic field in HTS coated conductors has a non-trivial influence AC loss coil windings. We report modelled real conductor asymmetry characteristics 1 MVA transformer design previously demonstrated by Robinson Research Institute as well stand-alone having same geometrical and electrical parameters low voltage (h...

Machine stator winding insulation degradation is one of the main results machine aging. It non-negligible once this process becomes asymmetric between phases. The traditional way to determine state health a partial discharge test. However, method requires system offline, which causes production loss and extra administrative burden. This paper presents an idea for better characterizing machine's...