Rotor cage faults as broken rotor bars, increased bars resistance and end-ring faults can be caused by thermal stresses, due to overload, overheating and thus mechanical stresses, magnetic stresses and dynamic stresses due to shaft torques. Environmental stresses as contamination or abrasion also contributes to the rotor cage faults. The rotor cage faults can also lead to the shaft vibration an...

This paper presents a new design to reduce torque ripple in Switched Reluctance Motors (SRMs). Although SRM possesses many advantages in terms of motor structure, it suffers from large torque ripple that causes problems such as vibration and acoustic noise. The paper describes new rotor and stator pole shapes with a non-uniform air gap profile to reduce torque ripple while retaining its average...

The induction motor with an axial air gap shows some performance characteristics that are superior to conventional induction machines. So it attracts the attention of the investigators to work on the performance prediction and design of these motors. In this paper a brief history of axial flux induction motors are presented and then the different structures of them are discussed. There are a lo...

The kantele, an ancient plucked string instrument, belongs to the family of zithers, and it is still used in traditional folk music in Finland, Northwest Russia, and the Baltic countries. Design rules for making the kantele louder are proposed and confirming analysis results are presented. A description of the main characteristics of the traditional design of the kantele is given, so that it su...

The rotor power losses in magnetic bearings are due to eddy currents, hysteresis, and windage. The influence of air gap magnetic flux density and air gap thickness is not well understood at this time. This paper presents measured results in two magnetic bearing radial configurations with a laminated rotor. The rotor power losses were evaluated by measuring the rundown speed of the rotor, in air...

An MgB2 race track coil intended for demonstrating a down scaled pole of a 10 MW direct drive wind turbine generator has been designed. The coil consists of 10 double pancake coils stacked into a race track coil with a cross section of 84 mm x 80 mm. The length of the straight section is 0.5 m and the diameter of the end sections is 0.3 m. Expanded to a straight section of 3.1 m it will produce...

This paper presents the effect on resonant frequency (fr) of equilateral triangular patch due to cover and space dielectric. It is observed that as the superstrate dielectric constant and its thickness increases, the resonant frequency decreases. For space dielectric, as the air gap between patch and space dielectric increases the resonant frequency increases with incremental change in fr < 0.4...

We demonstrated a miniature and in situ ~13-layer graphene nanomechanical resonator by utilizing a simple optical fiber Fabry-Perot (F-P) interferometric excitation and detection scheme. The graphene film was transferred onto the endface of a ferrule with a 125-μm inner diameter. In contrast to the pre-tension induced in membrane that increased quality (Q) factor to ~18.5 from ~3.23 at room tem...

In the permanent magnet linear synchronous motor (PMLSM), force ripple is harmful, useless and disturbing. The force ripple is basically composed of two components: detent force and mutual force ripple. This force is influenced by the geometric parameters of the permanent magnet (PM) motors; such as width, thickness and length of the magnet poles, length and thickness of the rotor and stato...