Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 2
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

Varying ohmic loss in the winding of electrical machines, which are operated at various operating points, results in temperature changes during operation. Particularly, when the temperature is varying dynamically, the insulation system suffers from repeated thermalmechanical stress, since the thermal expansion coefficients of the insulating materials and copper conductors are different. For the appropriate design of an insulation system, the effect of thermal-mechanical stress must be known. In the present work, motorettes are subjected to repeated thermal cycles. The expected lifetime is estimated and compared to the lifetime which is achieved by applying a lifetime-model which only considers thermal aging while ignoring thermal-mechanical stress effects. In addition, the hotspot temperature is simulated, the lifetime at the hotspot is estimated as theworst case. As expected, the results indicate that the thermal-mechanical stress plays a significant role during dynamic thermal aging of the winding insulation system. To better understand the thermal-mechanical stress effect, the resulting thermal-mechanical stress in a single wire is analyzed by the finite element method. A preliminary analysis of the aging mechanism of materials due to cyclic thermal-mechanical stress is performed with the theory of material fatigue.
Go to article

Bibliography

[1] Stone G.C., Boulter E.A., Culbert I., Dhirani H., Electrical insulation for rotating machines: design, evaluation, aging, testing, and repair, John Wiley & Sons (2004).
[2] Rothe R., Hameyer K., Life expectancy calculation for electric vehicle traction motors regarding dynamic temperature and driving cycles, 2011 IEEE International Electric Machines and Drives Conference (IEMDC), Niagara Falls, ON, Canada, pp. 1306–1309 (2011).
[3] Huang Z., Modeling and testing of insulation degradation due to dynamic thermal loading of electrical machines, Licentiate Thesis, Lund University, Lund (2017).
[4] Chen W., Nelson C., Thermal stress in bonded joints, IBM Journal of Research and Development, vol. 23, no. 2, pp. 179–188 (1979).
[5] Arrhenius S., On the heat of dissociation and the influence of temperature on the degree of dissociation of the electrolytes, Zeitschrift für Physikalische Chemie (in German, Über die Dissociationswärme und den Einfluss der Temperatur auf den Dissociationsgrad der Elektrolyte), vol. 4, no. 1, pp. 96–116 (1889).
[6] Dakin T.W., Electrical insulation deterioration treated as a chemical rate phenomenon, Transactions of the American Institute of Electrical Engineers, vol. 67, no. 1, pp. 113–122 (1948).
[7] Ruf A., Pauli F., Schröder M., Hameyer K., Lifetime modelling of non-partial discharge resistant insulation systems of electrical machines in dynamic load collectives, e & i Elektrotechnik und Informationstechnik (in German, Lebensdauermodellierung von nicht-teilentladungsresistenten isoliersystemen elektrischer maschinen in dynamischen lastkollektiven), vol. 135, no. 2, pp. 131–144 (2018).
[8] Pauli F., Schröder M., Hameyer K., Design and evaluation methodology for insulation systems of low voltage drives with preformed coils, 2019 9th International Electric Drives Production Conference (EDPC), Esslingen, Germany, pp. 1–7 (2019).
[9] Madonna V., Giangrande P., Lusuardi L., Cavallini A., Gerada C., Galea M., Thermal overload and insulation aging of short duty cycle, aerospace motors, IEEE Transactions on Industrial Electronics, vol. 67, no. 4, pp. 2618–2629 (2019).
[10] Sciascera C., Galea M., Giangrande P., Gerada C., Lifetime consumption and degradation analysis of the winding insulation of electrical machines, 2016 8th IET International Conference on Power Electronics, Machines and Drives (PEMD), Glasgow, UK, pp. 1–5 (2016).
[11] IEC 60505, Evaluation and qualification of electrical insulation systems (2011).
[12] Ruf A., Paustenbach J., Franck D., Hameyer K., A methodology to identify electrical ageing of winding insulation systems, 2017 IEEE International Electric Machines and Drives Conference (IEMDC), Miami, FL, USA, pp. 1–7 (2017).
[13] Pauli F., Ruf A., Hameyer K., Low voltage winding insulation systems under the influence of high du/dt slew rate inverter voltage, Archives of Electrical Engineering, vol. 69, no. 1, pp. 187–202 (2020).
[14] IEC 60034–18–41, Rotating electrical machines – Part 18–41: Partial discharge free electrical insulation system (Type I) used in rotating electrical machines fed from voltage converters – Qualification and quality control tests (2014).
[15] Nikolova G., Ivanova J., Interfacial shear and peeling stresses in a two-plate structure subjected to monotonically increasing thermal loading, Journal of Theoretical and Applied Mechanics, vol. 51 (2013).
Go to article

Authors and Affiliations

Liguo Yang
1
ORCID: ORCID
Florian Pauli
1
Kay Hameyer
1
ORCID: ORCID

  1. Institute of Electrical Machines (IEM), RWTH Aachen University, Schinkelstraße 4, 52062 Aachen, Germany
Download PDF Download RIS Download Bibtex

Abstract

An integration of the electrical machine and the gearbox is attracting particular attention for the design of modern electric and hybrid drive trains, since it saves overall space and subsequently increases the power density. Another benefit of a high level of integration is that it enables a combined application of oils as both cooling fluid for the electrical machine and as lubrication fluid for the transmission system. In this way, the power density of the integrated drive train can be further increased. During the oil cycling, conductive contaminations may be introduced and subsequently have an influence on the function of the insulation system of the electrical machine. In the present work, the influences of the cooling oil and its conductive contaminations, conductive particles as well as their combination with humidity, on the electrical and dielectric properties of the insulation system are studied. The results show that by application of the cooling oil, the partial discharge inception voltage (PDIV) of the winding insulation increases significantly so that an electrical breakdown is prone to happen before a partial discharge (PD) occurs. With increasing particle contamination, the PDIV of the insulation system decreases significantly, while the capacitance increases. Besides, conductive particles and humidity decrease the surface resistance and surface breakdown voltage of the insulation papers significantly. The results indicate that the conductive particle contaminations can play an important role for the electrical degradation of the insulation system.
Go to article

Bibliography

[1] Lehmann R., Petuchow A., Moullion M., Künzler M., Windel C., Gauterin F., Fluid Choice Based on Thermal Model and Performance Testing for Direct Cooled Electric Drive, Energies, vol. 13, no. 22, 5867 (2020), DOI: 10.3390/en13225867.
[2] Popescu M., Staton D.A., Boglietti A., Cavagnino A., Hawkins D., Goss J., Modern heat extraction systems for power traction machines – A review, IEEE Transactions on Industry Applications, vol. 52, no. 3, pp. 2167–75 (2016), DOI: 10.1109/TIA.2016.2518132.
[3] Tighe C., Gerada C., Pickering S., Assessment of cooling methods for increased power density in electrical machines, 2016 XXII international conference on electrical machines (ICEM), Lausanne, Switzerland, pp. 2626–2632 (2016), DOI: 10.1109/ICELMACH.2016.7732892.
[4] Ponomarev P., Polikarpova M., Pyrhönen J., Thermal modeling of directly-oil-cooled permanent magnet synchronous machine, 2012 XXth International Conference on Electrical Machines, Marseille, France, pp. 1882–1887 (2012), DOI: 10.1109/ICElMach.2012.6350138.
[5] Dan M., Hao J., Qin W., Liao R., Zou R., Mengzhao Z., Liang S., Effect of different impurities on motion characteristics and breakdown properties of insulation oil under DC electrical field, 2018 IEEE International Conference on High Voltage Engineering and Application (ICHVE), Athens, Greece, pp. 1–4 (2018), DOI: 10.1109/ICHVE.2018.8642256.
[6] Popescu M., Goss J., Staton D.A., Hawkins D., ChongY.C., Boglietti A., Electrical vehicles—Practical solutions for power traction motor systems, IEEE Transactions on Industry Applications, vol. 54, no. 3, pp. 2751–62 (2018), DOI: 10.1109/TIA.2018.2792459.
[7] McFadden C., Hughes K., Raser L., Newcomb T., Electrical conductivity of new and used automatic transmission fluids, SAE International Journal of Fuels and Lubricants, vol. 9, no. 3, pp. 519–26 (2016), DOI: 10.4271/2016-01-2205.
[8] Montonen J., Nerg J., Polikarpova M., Pyrhönen J., Integration principles and thermal analysis of an oil-cooled and-lubricated permanent magnet motor planetary gearbox drive system, IEEE Access, vol. 7, pp. 69108–18 (2019), DOI: 10.1109/ACCESS.2019.2919506.
[9] Carlo R.M., de Bruzzoniti M.C., Sarzanini C., Maina R., Tumiatti V., Copper contaminated insulating mineral oils-testing and investigations, IEEE Transactions on Dielectrics and Electrical Insulation, vol. 20, no. 2, pp. 557–63 (2013), DOI: 10.1109/TDEI.2013.6508759.
[10] Carlo R.M., de Sarzanini C., Bruzzoniti M.C., Maina R., Tumiatti V., Copper-in-oil dissolution and copper-on-paper deposition behavior of mineral insulating oils, IEEE Transactions on Dielectrics and Electrical Insulation, vol. 21, no. 2, pp. 666–73 (2014), DOI: 10.1109/TDEI.2013.004121.
[11] Antonov G.I., Working Group 17 (Particles in Oil) of Study Committee 12, Effect of particles on transformer dielectric strength, International Conference on Large High Voltage Electric Systems, Cigré, Paris, France (2000).
[12] Zhang J., Wang F., Li J., Ran H., Huang D., Influence of copper particles on breakdown voltage and frequency-dependent dielectric property of vegetable insulating oil, Energies, vol. 10, no. 7, 938 (2017), DOI: 10.3390/en10070938.
[13] Dan M., Hao J., Liao R., Cheng L., Zhang J., Li F., Accumulation behaviors of different particles and effects on the breakdown properties of mineral oil under DC voltage, Energies, vol. 12, no. 12, pp. 2301 (2019), DOI: 10.3390/en12122301.
[14] Pauli F., Ruf A., Hameyer K., Low voltage winding insulation systems under the influence of high du/dt slew rate inverter voltage, Archives of Electrical Engineering, vol. 69, no. 1, pp. 187–202 (2020), DOI: 10.24425/aee.2020.131767.
[15] Brütsch R., Chapman M., Insulating systems for high voltage rotating machines and reliability considerations, 2010 IEEE International Symposium on Electrical Insulation, San Diego, CA, USA, pp. 1–5 (2010), DOI: 10.1109/ELINSL.2010.5549737.
[16] Dymond J.H., Stranges N., Younsi K., Hayward J.E., Stator winding failures: contamination, surface discharge, tracking, IEEE Transactions on Industry Applications, vol. 38, no. 2, pp. 577–83 (2002), DOI: 10.1109/28.993182.
[17] Rahimi M.R., Javadinezhad R., Vakilian M., DC partial discharge characteristics for corona, surface and void discharges, 2015 IEEE 11th International Conference, Sydney, NSW, Australia, pp. 260–263 (2015), DOI: 10.1109/ICPADM.2015.7295258.
[18] IEC/TR 60664-2-1: 2011 ¸ Cor.:2011, Insulation coordination for equipment within low-voltage systems – Part 2–1: Application guide – Explanation of the application of the IEC 60664 series, dimensioning examples and dielectric testing (2011).
[19] IEC 60664-1:2007, Insulation coordination for equipment within low-voltage systems – Part 1: Principles, requirements and tests (2007).
[20] IEC 60172:2015, Test procedure for the determination of the temperature index of enamelled and tape wrapped winding wires (2015).
[21] IEC 60317-0-1:2013, Specifications for particular types of winding wires – Part 0–1: General requirements – Enamelled round copper wire (2013).
[22] IEC 62631-3-2:2015, Dielectric and resistive properties of solid insulation material – Part 3–2: Determination of resistive properties (DC Methods) – Surface resistance and surface resistivity (2015).
[23] Yang L., Pauli F., Hameyer K., Influence of thermal-mechanical stress on the insulation system of a low voltage electrical machine, Archives of Electrical Engineering, vol. 70, no. 1, pp. 233–44 (2021), DOI: 10.1109/ICPADM.2015.7295258.
[24] Akmal A.S., Borsi H., Gockenbach E., Wasserberg V., Mohseni H., Dielectric behavior of insulating liquids at very low frequency, IEEE Transactions on Dielectrics and Electrical Insulation, vol. 13, no. 3, pp. 532–538 (2006), DOI: 10.1109/TDEI.2006.1657965.

Go to article

Authors and Affiliations

Liguo Yang
1
ORCID: ORCID
Florian Pauli
1
Shimin Zhang
2
Fabian Hambrecht
1
Kay Hameyer
1
ORCID: ORCID

  1. Institute of Electrical Machines (IEM), RWTH Aachen University, Aachen, Germany
  2. Lubricant Division, TotalEnergies One Tech Solaize, France

This page uses 'cookies'. Learn more