A poster summarizing my thesis titled Circulating and Eddy-Current Losses in Random-Wound Electrical Machines

1. Who I am
• Post-doctoral researcher September 2017-
• D.Sc. 2017
• Numerical analysis of electrical machines
• Advanced winding loss model development
• Optimization
• Part-time consulting 2017-
Winding loss analysis
• 30-60+ % of losses occur in machine
windings
• 𝑅𝐼2 losses (DC-resistance)
• Circulating and eddy-current losses (AC-
resistance)
• Complex phenomenon  finite element
analysis (FEA)
• Complications:
• Fine structure  long computation
times
• Statistical uncertainty in geometry
• Results:
• 10 h  7 min computation time (10−10
precision)
• Sampling model for uncertainty
quantification
Department Postgraduate Student Research Seminar
Department of Electrical Engineering and Automation
Research Group of Electromechanics
Circulating and Eddy-Current Losses in
Random-Wound Electrical Machines
Antti Lehikoinen
antti.lehikoinen@aalto.fi
www.anttilehikoinen.fi
Open-Source FEA development
• FEA library for Matlab/Octave
• MIT-license  free to use
• Pure Matlab  no dependencies
• Available on GitHub
• Speed optimization  on par with
FORTRAN-based in-house software
• Tailored for electrical machines
• Non-linear time-stepping analysis
• Rotor motion
• Coupling to circuit equations
• Plotting
• Magneto-mechanical
• Thermal
Left: probability density of circulating current losses.
Right: current density in a slot with inverter supply.