Kilowatt Three-phase Rotary Transformer Design for Permanent Magnet DC Motor with On-rotor Drive System
Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
The aim of this thesis is to design a kilowatt three-phase step-down rotary transformer for
a permanent magnet DC motor. The permanent magnet DC motor has an on-rotor drive
system, and therefore requiring a power supply that can transfer power to its drive unit
without mechanical contact. The rotary transformer has a detached magnetic coupling
structure that qualifies it as a potential method for the wireless power transfer.
This thesis studies the rotary transformer as a static device, focusing on its core loss.
By using a transient finite element analysis of COMSOL Multiphysics and an iron loss
prediction model, the rotary transformer was optimized in terms of efficiency and power
density for the on-rotor drive system through proper material selection and geometry exploration.
After this, a mechanical design, which based on a literature review of the
influences of manufacturing processes on electrical steels, was proposed for realizing the
core fabrication and the rotary transformer assembly.
The results show that the rotary transformer can step down 400 V/50 Hz three-phase
voltage to 13.15V in a Delta-wye connection and output 1.17kW power over an air-gap
of 0.3mm with 95.94% overall efficiency. The proposed mechanical design enables the
transformer to minimize the core loss and the manufacturing cost. Without using resonant
inductive coupling, this transformer design simplifies the power supply for the motor,
thereby decreasing the motor manufacturing and maintenance cost.
Place, publisher, year, edition, pages
2016. , 91 p.
contactless energy transfer, transformer power loss, iron loss, iron loss model, rotary transformer, three-phase transformer, finite element method, COMSOL Multiphysics, electrical steel, electrical steel manufacturing process
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:miun:diva-27781OAI: oai:DiVA.org:miun-27781DiVA: diva2:932733
Subject / course
Master by Research TPRMA 120 higher education credits
Thungström, Göran, Docent