Partial discharge (PD) may occur in a transformer winding due to ageing processes, operational over stressing or defects introduced during manufacture. The presence of PD does not necessarily indicate imminent failure of the transformer but it will lead to serious degradation and ageing mechanisms which can be considered as a precursor of transformer failure. A necessary step is required in ord...

An open-end winding permanent magnet synchronous motor (PMSM) has a larger range of speed regulation than normal PMSM with the same DC voltage, and the control method is more flexible. It can also manage energy distribution between two power sources without a DC/DC converter. This paper aims at an electric vehicle equipped with OW-PMSM drive system with dual power sources and dual inverters; ba...

—Transformer terminal equivalents obtained via admittance measurements are suitable for simulating high-frequency transient interaction between the transformer and the network. This paper augments the terminal equivalent approach with a measurement-based voltage transfer function model which permits calculation of voltages at internal points in the regulating winding. The approach is demonstrat...

Superconducting machine designs have historically focused on an isolated, cryogenic rotor and conventional (copper) stator due to unacceptable levels of AC loss in a superconducting stator. Thus, reduction the armature windings is one key issues for achieving practical all-superconducting motors that could deliver unprecedented power density significantly reduce complexity. In this paper, 100 k...

Necessary and sufficient conditions are given for a satellite knot to be fibered. Any knot k̃ embeds in an unknotted solid torus Ṽ with arbitrary winding number in such a way that no satellite knot with pattern (Ṽ , k̃) is fibered. In particular, there exist nonfibered satellite knots with fibered pattern and companion knots and nonzero winding number.

This work is devoted to the calculation of the undulatory parameters and the study of the influence of te number parallel path of a winding on overvoltage compared to the frame and between turns (sections) in a multiturn random winding of an asynchronous motors supplied with PWMconverters. Keywords—Asynchronous Motors, Parallel path, PWMconverters, Undulatory process, Undulatory parameters, Und...

Hyperbolic versions of the integrable (1+1)-dimensional Heisenberg Ferromagnet and sigma models are discussed in the context of topological solutions classifiable by an integer ‘winding number’. Some explicit solutions are presented and the existence of certain classes of such winding solutions examined.

Misner space, also known as the Lorentzian orbifold R1,1/boost, is one of the simplest examples of a cosmological singularity in string theory. In this work, the study of weakly coupled closed strings on this space is pursued in several directions: (i) physical states in the twisted sectors are found to come in two kinds: short strings, which wind along the compact space-like direction in the c...

A method is proposed for determining the number of damaged stator windings in presence an asymmetric power supply system induction electric motor based on Park vector hodograph. As a result experiments simulation model, it was found that with symmetry voltages and windings, hodograph describes circle; all other cases ellipse. It has been established asymmetry voltage indicated by angle inclinat...