Search

Your search keyword '"Barater, Davide"' showing total 191 results
Start Over Author "Barater, Davide"
191 results on '"Barater, Davide"'

10. High power density electrical machines with hairpin windings

Author

Barater, Davide, Soltani, Mohammad <1986>, Barater, Davide, and Soltani, Mohammad <1986>

Abstract

Nowadays, electrical machines are seeing an ever-increasing development and extensive research is currently being dedicated to the improvement of their efficiency and torque/power density. Compared to conventional random windings, hairpin winding inherently features lower DC resistance, higher fill factor, better thermal performance, improved reliability, and an automated manufacturing process. However, several challenges need to be addressed, including electromagnetic, thermal, and manufacturing aspects. Of these, the high ohmic losses at high-frequency operations due to skin and proximity effects are the most severe, resulting in low efficiency or high-temperature values. In this work, the hairpin winding challenges were highlighted at high-frequency operations and at showing the limits of applicability of these standard approaches. Afterward, a multi-objective design optimization is proposed aiming to enhance the exploitation of the hairpin technology in electrical machines. Efficiency and volume power density are considered as main design objectives. Subsequently, a changing paradigm is made for the design of electric motors equipped with hairpin windings, where it is proven that a temperature-oriented approach would be beneficial when designing this type of pre-formed winding. Furthermore, the effect of the rotor topology on AC losses is also considered. After providing design recommendations and FE electromagnetic and thermal evaluations, experimental tests are also performed for validation purposes on a motorette wound with pre-formed conductors. The results show that operating the machine at higher temperatures could be beneficial to efficiency, particularly in high-frequency operations where AC losses are higher at low operating temperatures. The last part of the thesis focuses on comparing the main electromagnetic performance metrics for a conventional hairpin winding, wound onto a benchmark stator with a semi-closed slot opening design, and a continuous h

Published
2023

11. Hairpin windings for high reliability and high power density electrical machines

Author

Barater, Davide, Pastura, Marco <1994>, Barater, Davide, and Pastura, Marco <1994>

Abstract

In the last years the increasing demand of higher torque and power densities has led to the adoption of hairpin windings (HWs) in electrical machines, mainly in those intended for automotive applications. However, this winding topology is quite sensitive to AC losses, hence one of their main challenges is represented by their reduction. This work deals with different design aspects related to the enhancements of some performance figures of rotating electrical machines for traction applications, above all power density and reliability, mainly through the adoption of HWs., In the last years the increasing demand of higher torque and power densities has led to the adoption of hairpin windings (HWs) in electrical machines, mainly in those intended for automotive applications. However, this winding topology is quite sensitive to AC losses, hence one of their main challenges is represented by their reduction. This work deals with different design aspects related to the enhancements of some performance figures of rotating electrical machines for traction applications, above all power density and reliability, mainly through the adoption of HWs.

Published
2023

24. Partial Discharges in Electrical Machines for the More Electric Aircraft—Part I: A Comprehensive Modeling Tool for the Characterization of Electric Drives Based on Fast Switching Semiconductors

Author

Pastura, Marco, Nuzzo, Stefano, Immovilli, Fabio, Toscani, Andrea, Rumi, Alberto, Cavallini, Andrea, Franceschini, Giovanni, Barater, Davide, Pastura, Marco, Nuzzo, Stefano, Immovilli, Fabio, Toscani, Andrea, Rumi, Alberto, Cavallini, Andrea, Franceschini, Giovanni, and Barater, Davide

Subjects
RAISE, Hardware_INTEGRATEDCIRCUITS, H2020, Clean Sky 2 JU, Hardware_PERFORMANCEANDRELIABILITY, Electric drives, electrical machines, insulation, insulation stress, more electric aircraft, partial discharges, reliability, voltage distribution, voltage overshoot, wide bandgap
Abstract

This paper proposed a modelling approach for the comprehensive analysis of high-frequency challenges in electrical drives designed for aerospace applications, in particular the overvoltage at the machine terminals and the voltage distribution within windings. After a separate description of the models for the estimation of these insulation stress sources, the combined model was detailed. The main benefit of developing a combined, flexible and comprehensive tool is that both overvoltage at machine terminals and uneven voltage distribution can be calculated simultaneously, without neglecting the voltage overshoot when estimating the voltage distribution (and vice versa). In fact, an accurate calculation of the terminal overvoltage is necessary to provide a good estimation of the voltage within winding turns since its waveform shape can be quite different with respect to the converter output, even with cables of a few meters. A case study based on a real aerospace application was considered to investigate the model validity and accuracy. Experimental results were performed on a complete system comprising a SiC-based converter, a connecting cable and a machine stator, proving the simulation model accuracy in terms of peak voltages of both the line-to-line terminal voltage and the turn voltage distribution across the first turns, which are the most relevant quantities for the sake of this study as well as for the investigations of the subsequent companion papers. In the forthcoming papers, the effects of different rise times and cable lengths on the inception of partial discharges will be investigated through fast parametric simulation carried out using the proposed combined model. The feasibility of using conventional insulation systems for aircraft applications using SiC drives fed by a ±270 V DC bus voltage will be discussed, with the aim of signaling and finding solutions to improve the overall reliability.

Published
2021

27. Multi Three-Phase Hairpin Windings for High- Speed Electrical Machine: Possible Implementations

Author

Pastura, Marco, Barater, Davide, Nuzzo, Stefano, and Franceschini, Giovanni

Subjects
JTI-CS2-2018-CfP09-SYS-03-19, AC losses, Horizon 2020, AUTO-MEA, High-Speed, Multi-phase, Automotive, Multi three-phase, Clean Sky 2 Joint Undertaking, European Union (EU), GA 865354, Hairpin
Abstract

—This work provides an in-depth critical analysisrelated to the feasibility of combining multi three-phase winding layouts with the ever-spreading hairpin technology. After anintroduction on the advantages and challenges of both hairpin and multi-phase windings, more details on how these twotechnologies can be combined are provided. Then two similar stator geometries, with 72 and 96 slots, are analyzed in detailexploiting an 8 poles permanent magnet – assisted synchronous reluctance motor for traction applications. A relevant set offeasible winding configurations are modelled and analyzed through finite element simulations. For every machine, abreakdown of the power losses is provided and compared against that of the same machine topologies having randomwoundwindings with stranded round conductors. The main results and possible solutions to increase the machineperformance are then provided. © 20XX IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. &nbsp

Published
2021

Catalog

Books, media, physical & digital resources
See catalog results