Lumped parameter thermal model for large-diameter, low-speed permanent magnet synchronous motors
No Thumbnail Available
URL
Journal Title
Journal ISSN
Volume Title
School of Engineering |
Master's thesis
Authors
Date
2024-08-30
Department
Major/Subject
Mcode
Degree programme
Master's programme in Mechanical Engineering
Language
en
Pages
116
Series
Abstract
The purpose of this study was to create a lumped parameter thermal model for megawatt-scale, large-diameter, low-speed permanent magnet synchronous electric motors, and to use the model to simulate and analyse the average temperatures of key motor components. Based on the results, the study qualitatively evaluated how useful such a model is for early-stage electric motor design. A literature review was conducted, covering the basics of permanent magnet motors, the physical mechanisms that cause heat losses in motors, losses in different motor components, and different motor cooling types. The thermal model was built in KiCad 8.0 and simulated using its inbuilt ngspice circuit simulator. The study explains in detail the equations and different elements needed to build a lumped parameter thermal model in electronic design software, covering each major permanent magnet motor component separately. The resulting model is shown to quite accurately predict the component temperatures of a hypothetical motor design, when compared to temperature results from a computational fluid dynamics simulation. The usefulness of lumped parameter thermal models for early-stage motor design was found to be high when fast iterative design is needed. The model can be used to establish a thermal design baseline for different motor sizes, as long as the motor topology remains the same. The usefulness in cases where the motor topology changes was found to be lower due to longer required model setup time. The simulation setup and solving time for the tested thermal model was found to be only a fraction of the time required for a detailed computational fluid dynamics simulation. The thermal model solving time was found to be in the order of seconds on regular desktop hardware.Description
Supervisor
Kuosmanen, PetriThesis advisor
Säkkinen, PetriKeywords
lumped parameter thermal model, permanent magnet electric motor, low-speed, large diameter, large radius, early-stage design, megawatt-scale