Exploitation of iron B-H local hysteresis for the rotor position detection of a PM motor

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Magnetite nanoparticles (Fe 3 O 4 NPs) are limited by low surface area, fewer functional groups, high agglomeration tendency, and poor dispersibility in aqueous media. In this study, Fe 3 O 4 NPs were functionalized with activated carbon (Fe 3 O 4 @AC) through co-precipitation in compositional weight ratios of Fe 3 O 4 : AC of 1:1, 2:1, 3:1, designated as Fe 3 O4@AC-1, Fe 3 O4@AC-2, Fe 3 O4@AC-3, respectively. Ferric chloride from acid leached iron oxide waste powder was used as a starting material for Fe 3

A slotless magnetically-levitated high speed motor had been designed and build prior to the beginning of this project. This report presents the work done to develop a slotted alternative design to this motor. In this study, the principle of magnetically-levitated motors for high speed application is presented. Pros and cons of main topologies are highlighted. An optimisation procedure of geometric parameters for slotted stator with a given rotor is developed and explained. The optimization is run for the ro

EPS systems are more and more used in automotive application to save energy and create a more flexible tool for driver. A BLAC motor has been designed in the Prof. Shen's Laboratory and has a very sinusoidal waveform. In order to avoid the detent torque, a sinusoidal voltage supply has to be provided to the so-called Brushless AC motor (BLAC). The aim of the project is to analyze the possibility to realize this driver and to realize the controller. Control theory and current measurements will have to be car

The objective of this project is to determine in an analytical way the modes of vibration of the stator of a brushless DC motor. The knowledge of these modes is important. Once the vibration modes are determined we can avoid their excitation and thus reduce the noise emitted by the motor and its stress. This task is already performed by the use of finite element methods but they have the disadvantage of hiding the relations between the geometry of the stator and the vibration frequencies. In the first part

A digital controller for piezoelectric motors was developed. The controller tunes the driving frequency in order to maximize the power transmitted to the motor. A maximum of power is absorbed when the resonant frequency of the mechanical and electrical part of the piezoelectric motor are equal. This frequency varies in the first place because of the applied force. The control method consists of comparing two values of the transmitted power, measured at different moments, and deciding as a function of the re

In order to create a new solar aircraft totally powered by the sun, a new method able to handle such a complex system must be developed. The project aim is to make a round-the-world flight in so as to promote the sustainable development. The aircraft power train will consist of solar cells placed on the wings, the energy storage system, the energy management electronics, the brushless DC motor and propellers. This paper presents the method to optimize the motor together with the propellers, to save the maxi

The presence of oil in domestic heat pumps is a hindrance, particularly for enhanced surface evaporators and for advanced concepts based on two-stage cycles. Very compact oil-free dynamic compressor directly driven by high speed electric motors and supported on refrigerant vapor bearings represent a promising alternative. This paper presents a design analysis of the first stage prototype with the various tradeoffs between the impeller characteristics to follow the seasonable heat demand, the bearing and rot

This paper describes a new method to estimate the standstill position of Permanent Magnet Synchronous Motors (PMSM). The method is based on the anisotropic properties of permanent magnets and is therefore referred to as Magnetic Anisotropy Method (MAM). The MAM method differs significantly from all standard standstill position detection methods previously presented in the literature. The proposed method is totally independent of saliency and saturation effects and can therefore be used in many types of PMSM

This paper presents an analytical formula for the permanent magnet (PM) magnetomotive force (MMF) in a slotted PM rotating motor. To derive this formula, an analytical 2D solution of Poisson's equation for the equivalent slotless configuration using the Fourier series is applied. The formula comprises the case when the PM poles are not symmetrical. The obtained PM MMF can be used to determine the magnetic field using the slot modulation

Swissmetro is a MAGLEV Project between the main cities of Switzerland, designed for a speed up to 500 [km/h] in two tunnels under partial vacuum. Two propulsion variants are considered: - the short stators of the linear homopolar motors are fixed with the tunnel tracks; - the stator of the motors is on board of the vehicles. The levitation, the guidance and the transfer of energy are independent. The authors investigate the possibilities to combine the propulsion with the levitation and the guidance. Polari

We present an original concept of manipulation of magnetic microbeads in a microchannel. It is based on the dynamic motion of a self-assembled structure of ferrimagnetic beads that are retained within a microfluidic flow using a local alternating magnetic field. The latter induces a rotational motion of the magnetic particles, thereby strongly enhancing the fluid perfusion through the magnetic structure that behaves as a dynamic random porous medium. The result is a very strong particle-liquid interaction t

The attention of the fusion magnet specialists has been drawn in the last years to the volt-ampere characteristic (VAC) of the large cable-in-conduit conductors (CICC), as early voltage was observed in conductor and model coil tests, far away from the expected critical current. In this paper, the studies and models developed in the last decades for the VAC of bulk material and multifilament strands are shortly reviewed. The practical role of the index n of the VAC, both at the industry and in the magnet des

Direct measurements of longitudinal (d(33)) and transverse (d(31)) piezoelectric coefficients have been made on cuboid samples of 001-poled 0.955Pb[Zn1/3Nb2/3]O-3-0.045PbTiO(3) (PZN-4.5PT) and 0.68Pb[Mg1/3Nb2/3]O-3-0.32PbTiO(3) (PMN-32PT) single crystals. The measurements were made in a Berlincourt-type press over a wide range of dynamic and static bias stresses. In the transverse mode, the response was found to be essentially anhysteretic and d(31) was independent of the dynamic stress amplitude. In c

The German SUpraLeiterTest ANlage (SULTAN) test facility at the Centre de Recherches en Physique des Plasma (CRPP), Villigen, is a worldwide unique tool to test high current superconductors over a broad range of operating conditions. The key component of the facility is a set of forced flow superconducting coils to generate a background field up to I I T. A flux pump supplies the test sample with current up to 100 kA. A set of pulsed coils generates a transverse, time varying field, with amplitude up to 4 T

In many applications, industry has tried to develop sinusoidal supply for brushless DC (BLDC) motors. This paper describes a method that still keeps a simple 2 phases-on sensorless method and achieves sinusoidal supply, which is needed to avoid speed oscillations due to the very low mechanical constant of small motors. The method is based on back-EMF sensing. Principles, measures and extensions are proposed. The results of industrial applications are exposed and discussed

The present study aims at a better understanding of the high piezoelectric properties encountered in lead-based ferroelectrics by focusing on the extrinsic contributions to the response. The main characteristics of these materials are the highly nonlinear character of the electro-mechanical response and the presence of a morphotropic phase boundary (MPB) where properties are reaching a maximum. Thus, our approach was first to develop a new description for the piezoelectric hysteresis and nonlinearities and

We have developed a cheap and simple trilayer printed circuit board (PCB)-based technology, adapted for the fabrication of fluxgate magnetic sensors. The two outer layers of the PCB stack comprise the electrical windings of the fluxgate, while the inner layer is made of patterned amorphous magnetic core with extremely high relative magnetic permeability (µr100,000). The output voltage and the sensitivity of the fluxgate devices have been studied as a function of the external field and of the geometry of the

Ag-sheathed (Bi,Pb)2Sr2Ca2Cu3O10 tapes have been developed with a special filament configuration that can be of great interest when a magnetic field is applied to the tape at a significant angle with respect to the a–b planes of the superconductor. The fabrication process we propose allows the preparation of long conductors in which the filaments can be inclined with respect to the plane of the tape, according to the magnetic flux profile. Such tapes can be useful in a variety of applications, as for the ou

An electronic compass made of a new planar 2D micro-fluxgate sensor is presented. The magnetometer is integrated in a standard CMOS process, and uses a post-processed cross shape ferromagnetic amorphous core. This core is diagonally placed above a single square excitation coil common to both measurement axes. The silicon chip includes the driving and readout electronics, the excitation and pick-up coils made of the two CMOS process metallization layers. The ferromagnetic core is integrated from commercially

Rhombohedral Pb(Zr0.70Ti0.30)O-3 thin films of four different well-defined textures, namely, (100), (111), bimodal (110)/(111), and (100)/(111), were prepared by a sol-gel method. The films were characterized in terms of grain size, presence of second phases, surface roughness, columnarity of grains, and other microstructural features. The dielectric, ferroelectric, and fatigue properties were investigated, with emphasis on the hysteresis switching characteristics. Results are discussed from the reference p

Exploitation of iron B-H local hysteresis for the rotor position detection of a PM motor

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Compositional effects of rice husk based activated carbon on properties of steel waste derived magnetite nanoparticles

Alternative, Magnetically-Levitated Motor Topologies for High Speed

A BLAC Motor Drive for EPS System Application

Vibration modes of the brushless DC motor

Digital control of a piezoelectric motor

Brushless DC motor optimization process - Choice between standard or straight tooth shape

High-Speed Low Power Radial Turbocompressor For Oil-Free Heatpumps

A new standstill position detection technique for non-salient PMSM's using the Magnetic Anisotropy Method (MAM)

Analytical formula for rotating motor permanent magnet MMF in a general case

SWISSMETRO: Combined Propulsion with Levitation and Guidance

Manipulation of Self-Assembled Structures of Magnetic Beads for Microfluidic Mixing and Assaying

The index n of the voltage-current curve, in the characterization and specification of technical superconductors

Direct piezoelectric effect in relaxor-ferroelectric single crystals

Upgrade of operating range for SULTAN test facility

Implementation of a lowcost sinusoidal supply for BLDC motor

Extrinsic contributions to the piezoelectric response of lead-based ferroelectrics

Printed circuit board integrated fluxgate sensor

Development of Ag-sheathed Bi(2223) tapes with oriented filaments

CMOS planar 2D micro-fluxgate sensor

Influence of texture on the switching behavior of Pb(Zr0.70Ti0.30)O3 sol-gel derived thin films