In this paper, a set of correlations for the windage power losses in a 4 kW axial flux permanent magnet synchronous machine (AFPMSM) is presented. In order to have an efficient machine, it is necessary to optimize the total electromagnetic and mechanical losses. Therefore, fast equations are needed to estimate the windage power losses of the machine. The geometry consists of an open rotor–stato...

The paramagnetic complex bis(oxazolinylphenyl)amine–Fe(III)Cl2 is investigated by means of solid-state proton NMR at 18.8 T (800 MHz) using magic-angle spinning at 65 kHz. Spin echoes that are excited and refocused by combs of rotor-synchronized pulses in the manner of ‘Delays Alternating with Nutation for Tailored Excitation’ (DANTE) allow one to characterize different chemical environments th...

Concepts for sensorless position control of induction motor drives rely on anisotropic properties of the machine rotor. The built-in spatial anisotropy is detected by injecting a high-frequency flux wave into the stator. The resulting stator current harmonics contain frequency components that depend on the rotor position. Models of the rotor saliency serve to extract the rotor position signal u...

Most past investigations of dual-spin spacecraft have assumed that the platform and rotor are symmetric and rigidly connected. Recently, Cretcher and Mingori, Wenglarz, Willems, and Bainum have considered the effects of flexibility in different parts of dual-spin spacecraft. Scher and FarrenkopP have considered the effects of an asymmetric rotor rigidly connected to the platform. However, the e...

This paper provides a comprehensive review of the recent development on the switched reluctance machine operating in generating mode in both the low and high speed operations. The machine consists of a salient rotor and stator poles and controlled via switching of the power electronic devices. There is a steady development of the machine operating in the motoring mode; however, its generating o...

This paper presents a novel double-stator permanent-magnet machine integrated with a triple rotor magnetic gear structure, which is proposed to address problems of mechanical geared generators for low-speed applications. Torque transmission is based on three rotors consisting of prime permanent-magnet (PM) poles in the middle rotor and field PM poles in the inner and outer rotors. The proposed ...

By combination of fast magic-angle spinning (MAS) and detection of the free-induction decay during a rotor-synchronized quadrupolar Carr-Purcell-Meiboom-Gill (QCPMG) train of refocusing pulses, the sensitivity of quadrupolar-echo MAS NMR spectra for the central transition of half-integer quadrupolar nuclei exhibiting large quadrupolar couplings may be significantly enhanced. Enhancements by an ...

A Huey Cobra helicopter was just finishing up a nighttime practice run. The pilot was working on his low hover maneuvers at the air base when he tipped his tail rotor sharply backward, snapping off his tail boom. Without the tail —which keeps a helicopter from spinning around in circles— the helicopter took off like a pinwheel, sliding down the runway doing 360’s in a brilliant shower of sparks...

The methods of multi-DOF actuator orientation detection based on machine vision and magnetic field sensor and neural network based multisensor fusion are presented in this paper. Special grid pattern is printed on the surface of rotor according to the pseudo-random encoder for the camera capturing the image of the rotor. The magnetic field sensors are adopted and properly placed circling the sh...

Active magnetic bearing (AMB) systems support rotating shafts without any physical contact, using electromagnetic forces. Each radial AMB uses two pairs of electromagnets at opposite sides of the rotor. This allows the rotor to float in the air gap, and the machine to operate without frictional losses. In active magnetic suspension, displacement sensors are necessary to detect the radial and ax...