Professor Geraint Jewell
PhD, BEng
School of Electrical and Electronic Engineering
Professor
Lecturer for Aerospace Engineering
Full contact details
School of Electrical and Electronic Engineering
- Profile
-
I am a graduate of the Department (BEng 1988, PhD 1992) and have been a member of the academic staff since 1994. During my time on the academic staff I held an EPSRC Advanced Research Fellowship (2000-2005) and a Royal Society Industry Fellowship at Rolls-Royce (2006-2008).
I have been Director of the Rolls-Royce University Technology Centre in Advanced Electrical Machines since 2006 and Director of the EPSRC Future Electrical Machines Manufacturing Hub since 2019.
Alongside my mainstream academic roles within the Department, I served as the Faculty of Engineering’s first Faculty Director of Research and Innovation from 2008-2011 and as Head of the Department from 2013 to 2019.
My PhD research was concerned with the electromagnetic modelling and design of capacitor- discharge multipole magnetizing fixtures for NdFeB magnets, which at that time were a relatively recent development that posed many magnetization challenges.
I then applied the underpinning transient modelling to the problem of eddy currents in pulsed magnetometry for permanent magnet characterisation.
Since becoming a member of academic staff my interests have broadened to cover many aspects of electromechanical devices including electrical machines (permanent magnet, switched reluctance, synchronous reluctance) and linear actuators.
Much of this research has been directed towards aero-engine applications in collaboration with Rolls-Royce. This research has included high temperature devices (many around 400℃ but with one up to 800℃) and several demonstrator starter-generators for aero-engines.
I have also had a long-standing interest in core loss calculation methods for electrical machines. I have supervised ~20 PhD students to completion across a wide range of electromagnetic and electro-mechanical topics.
- Research interests
-
- Power dense electrical machines for aerospace applications
- Linear electromagnetic actuators
- Electromagnetic modelling of novel devices
- Publications
-
Journal articles
- Thermal Failure of Stator Winding Insulation and Useful Life Assessment by Impedance Spectroscopy. EEE Transactions on Industry Applications, 1-12.
- Degradation-Informed Coil Insulation Modelling by Impedance Frequency Response Analysis. IEEE Transactions on Industry Applications, 1-12.
- AC Loss Calculation for Litz Wire Windings in Electrical Machines. IEEE Transactions on Transportation Electrification, 1-1.
- A Hybrid Winding Design to Reduce AC Losses in Electrical Machines with Bar Conductors. IEEE Transactions on Transportation Electrification, 1-1.
- Thermal degradation profile mapping in stator coil insulation by impedance spectroscopy. IEEE Transactions on Industry Applications, 61(4), 6110-6119. View this article in WRRO
- Localized Asymmetric Behavior of Common-Mode Current Through Bearing Balls. IEEE Transactions on Energy Conversion, 1-11.
- Influence of remote laser cutting on magnetic loss and mechanical properties in 0.2 mm silicon steel. Journal of Magnetism and Magnetic Materials, 607. View this article in WRRO
- Combined electromagnetic and mechanical design optimization of interior permanent magnet rotors for electric vehicle drivetrains. World Electric Vehicle Journal, 15(1). View this article in WRRO
- A model to account for magnetic permeability changes resulting from edge damage caused by laser cutting in a high performance cobalt-iron alloy. Journal of Magnetism and Magnetic Materials, 584. View this article in WRRO
- Novel stator slot opening to reduce electrical machine bearing currents. IEEE Transactions on Magnetics, 59(11). View this article in WRRO
- Geometrical control of eddy currents in additively manufactured Fe-Si. Materials & Design, 230. View this article in WRRO
- Experimental ball bearing impedance analysis under different speed and electrical conditions. IEEE Transactions on Dielectrics and Electrical Insulation, 30(3), 1312-1321. View this article in WRRO
- Inspection of enamel removal using infrared thermal imaging and machine learning techniques. Sensors, 23(8). View this article in WRRO
- Cracking of soft magnetic FeSi to reduce eddy current losses in stator cores. Additive Manufacturing, 70. View this article in WRRO
- Coupled mechanical-magnetic analysis of cut-edge damage in thin sheet electrical steels. International Journal of Mechanical Sciences.
Conference proceedings
- Design, optimization and performance analysis of 250 kW permanent magnet machine for hybrid electric propulsion of civil aircrafts. IET Conference Proceedings, Vol. 2025(3) (pp 141-148)
- Fast Algorithm for Eliminating Common Mode Voltage in Dual Three-phase Inverter. 2024 IEEE Energy Conversion Congress and Exposition (ECCE) (pp 3895-3901), 20 October 2024 - 24 October 2024.
- Modelling of Insulation in Concentrated Stator Coils for Characterisation and Material Changes. 2024 International Conference on Electrical Machines (ICEM) (pp 01-08), 1 September 2024 - 4 September 2024.
- Identification of Thermal Failure Profiles in Stator Winding Insulation by Impedance Spectroscopy. 2024 International Conference on Electrical Machines (ICEM) (pp 1-7), 1 September 2024 - 4 September 2024.
- Developing requirements for future electrical machine manufacture to achieve a net zero future. IET Conference Proceedings, Vol. 2023(29) (pp 15-19)
- Manufacturing processes for 2.5D laminated stacks. 2023 13th International Electric Drives Production Conference (EDPC) (pp 1-5), 29 November 2023 - 30 November 2023.
- Flexible Manufacturing of High-value Low-volume Electrical Machines through Robotic Coil Winding. 2023 13th International Electric Drives Production Conference (EDPC) (pp 1-10), 29 November 2023 - 30 November 2023.
- Fibre Bragg Grating Sensor Based Winding Strain Monitoring and Insulation Lifetime Prediction. 2023 IEEE Transportation Electrification Conference and Expo, Asia-Pacific (ITEC Asia-Pacific) (pp 1-5), 28 November 2023 - 1 December 2023.
- An Investigation of Substituting Copper with Aluminum Conductors in a High Power, Medium Speed SPM Machine. 2023 IEEE Transportation Electrification Conference and Expo, Asia-Pacific (ITEC Asia-Pacific) (pp 1-8), 28 November 2023 - 1 December 2023.
- Effect of Load on Impedance Characteristics of High Frequency Circulating Bearing Current Path in Stator Laminations for an Inverter Fed AC Machine. 2023 26th International Conference on Electrical Machines and Systems (ICEMS) (pp 952-957), 5 November 2023 - 8 November 2023.
- A New Analytical Model for Voltage Stress Analysis at Neutral Point of Stator Windings. 2023 26th International Conference on Electrical Machines and Systems (ICEMS) (pp 1364-1369), 5 November 2023 - 8 November 2023.
- Thermal Degradation Profile of Concentrated Stator Winding Insulation by Impedance Spectroscopy. 2023 IEEE 14th International Symposium on Diagnostics for Electrical Machines, Power Electronics and Drives (SDEMPED) (pp 554-560), 28 August 2023 - 31 August 2023.
- Line-connected permanent magnet generator with adjustable excitation for variable-frequency AC aircraft power systems. 2023 IEEE International Electric Machines & Drives Conference (IEMDC) (pp 1-7), 15 May 2023 - 18 May 2023.
Preprints
- Thermal Failure of Stator Winding Insulation and Useful Life Assessment by Impedance Spectroscopy. EEE Transactions on Industry Applications, 1-12.
- Professional activities and memberships
-
- Rolls-Royce University Technology Centre in Advanced Electrical Machines