A noninvasive technique for identifying the magnetic properties of permanent magnet synchronous machines core material

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Influence of the Lamination Material and Rotor Pole Geometry on the Performance of Wound Field Synchronous Machines

This paper examines the influence of the lamination material and rotor pole geometry on the steady-state performance of a wound field synchronous machine operated in the generating mode. The investigations are carried out through 2D finite element analyses using a commercial software package. Non-Oriented silicon-iron alloys of various grades are selected to recognize the impact of their magnetic properties on the machine performance. Different methods for the extrapolation of BH curves from low medium field levels to saturation are reviewed and compared. The effect of using different materials on both the rotor and the stator core is assessed in terms of variation of the air gap power, the torque ripple and the core losses. The performance of a new machine featuring a higher-grade lamination material and a refined rotor pole geometry are compared at constant air gap power with those of the reference machine. The results show that, depending on the adopted strategy, it is possible to almost halve the torque ripple and slightly decrease the mass of the rotor core

Comparison of Nonoriented and Grain-Oriented Material in an Axial Flux Permanent-Magnet Machine

The performance and iron losses of an axial flux permanent-magnet synchronous machine (AFPMSM) using nonoriented (NO) steel are compared with the performance and iron losses of an AFPMSM using grain-oriented (GO) material. The machine is modeled by several 2-D finite element models in circumferential direction, at different radii. The material model for the GO material is an anhysteretic anisotropic model based on the magnetic energy. The magnetic energy is computed by using several measured quasi-static -loops on an Epstein frame in seven directions starting from the rolling direction to the transverse direction. The losses are calculated a posteriori, based on the principles of loss separation and dynamic loop measurements. A loss model was made for each of the seven directions, assuming unidirectional fields. In comparison with the more usual NO material, both the saturation induction and the torque are higher with GO material. The magnetic field in the GO material is lower than for NO material in the major part of the iron, but higher in the tooth tips where the field is not in the rolling direction. The stator iron losses are about 7 times lower for the considered GO compared to the NO material

The latest advances in wireless communication in aviation, wind turbines and bridges

Present-day technologies used in SHM (Structural Health Monitoring) systems in many implementations are based on wireless sensor networks (WSN). In the context of the continuous development of these systems, the costs of the elements that form the monitoring system are decreasing. In this situation, the challenge is to select the optimal number of sensors and the network architecture, depending on the wireless system’s other parameters and requirements. It is a challenging task for WSN to provide scalability to cover a large area, fault tolerance, transmission reliability, and energy efficiency when no events are detected. In this article, fundamental issues concerning wireless communication in structural health monitoring systems (SHM) in the context of non-destructive testing sensors (NDT) were presented. Wireless technology developments in several crucial areas were also presented, and these include engineering facilities such as aviation and wind turbine systems as well as bridges and associated engineering facilities

Abbreviated BioBrick Prefix and Suffix for More Efficient Primer Design

This Request for Comments (RFC) modifies the assembly standard for biological parts proposed in BBF RFC 10 by removing the NotI restriction site from the BioBrick Prefix and Suffix

Methodology to evaluate the influence of electrical steel properties on the design of wind turbine generators

De hernieuwbare energiesector wint de voorbije jaren meer en meer aan belangstelling. Een belangrijke component van deze sector is windenergie. De windenergiemarkt heeft zich de laatste jaren heel snel ontwikkeld. De windturbines en het nominale vermogen van de bijhorende windgeneratoren bij zowel onshore als offshore toepassingen zijn beduidend groter geworden. Er werden in het verleden verscheidene windturbineconcepten ontwikkeld. Typische elektrische machines in die toepassing zijn inductiegeneratoren, elektrisch bekrachtigde synchrone generatoren en synchrone generatoren met permanente magneten. Als men de huidige status van de windenergiemarkt bekijkt, komt men snel tot de vaststelling dat dit laatste type generatoren heel wat belangstelling geniet bij de fabrikanten van windturbines voor grote vermogens. Ook in de wetenschappelijke wereld gaat dit type generatoren niet onopgemerkt voorbij. Het voorgestelde doctoraatswerk richt zich op de ontwikkeling van nieuwe methoden voor elektromagnetische en thermische analyse van dit type generatoren met het oog op de maximalisatie van de jaaropbrengst van elektriciteit door een windturbine. Een belangrijk deel hierbij is de studie van de invloed van de gebruikte materialen in de elektrische generator

Przypadek chorej z długotrwałą odpowiedzią na immunoterapię pembrolizumabem w pierwszej linii poddanej zabiegowi kardiochirurgicznemu powikłanemu COVID-19

Chora w wieku 60 lat została skierowana do ośrodka autorów w celu diagnostyki i leczenia guza płuca prawego. Rozpoznano raka gruczołowego płuca w IV stadium zaawansowania, z wysoką ekspresją PD-L1. Pacjentka została zakwalifikowana do monoterapii pembrolizumabem w 2019 roku. W czasie leczenia przebyła pomyślnie zabieg kardiochirurgiczny wymiany zastawki aorty z powodu ciężkiej stenozy oraz zapalenie płuc w przebiegu COVID. Odpowiedź na leczenie przeciwnowotworowe była bardzo dobra (PR — częściowa odpowiedź wg RECIST 1.1) i utrzymuje się nadal. Dotąd chora otrzymała 63 cykle podania pembrolizumabu z dobrą tolerancją leczenia

3-D FEM Investigation of Eddy Current Losses in Rotor Lamination Steel Sheets

In this paper, a test setup that emulates field conditions equivalent to the ones of the rotor of a Salient Pole Synchronous Machine (SPSM) is presented. A 3-D Finite Element Method (FEM) model of the test setup is used to examine the induced eddy currents and to estimate losses using direct eddy current calculation method. The high mesh resolution of the model enables an accurate calculation and detailed illustration of the induced eddy currents as well as the estimation of related losses via direct computation within the volume of the test samples. A comparison of the estimated eddy current losses is made for different lamination thicknesses and materials of the test object. In the paper it is shown that the approximation that the eddy current losses are directly proportional to the square of the lamination thickness is not valid in the considered cases.Part of proceedings: ISBN 978-1-5386-2477-7QC 20181029</p

Comparison of iron loss models for electrical machines with different frequency domain and time domain methods for excess loss prediction

The goal of this paper is to investigate the accuracy of modeling the excess loss in electrical steels using a time domain model with Bertotti’s loss model parameters n0 and V0 fitted in the frequency domain. Three variants of iron loss models based on Bertotti’s theory are compared for the prediction of iron losses under sinusoidal and non-sinusoidal flux conditions. The non-sinusoidal waveforms are based on the realistic time variation of the magnetic induction in the stator core of an electrical machine, obtained from a finite element-based machine model