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Iron core loss in transient excitation mode
This is an example of the iron losses calculation in transient magnetic simulation performed with QuickField software.
Problem Type:
Plane problem of transient magnetics.
Geometry:
All dimensions are in millimeters
Given:
Core type: E19/8/53C81 (by Ferroxcube)
Magnetic permeability of MnZn ferrite μ=2700
Primary winding:
Number of turns  80
Waveform  periodic rectangular wave
Frequency  20 kHz
Voltage magnitude  40 V
Task:
Calculate core loss.
Solution:
According to Dartmouth university report^{1} published by Dr. Sullivan and Dr. Harris for rectangular waves it is possible to use Steinmetzlike equation (referred as equation (8) in this report):
P_{v}[W/m^{3}] = max(k_{1}·f^{α1}·B^{β1}, k_{2}·f^{α2}·B^{β2}),
with materialdependent parameters, which for the Ecore E19/8/53C81 from Ferroxcube are:
k_{1} = 18.02, α1 = 1.23, β1 = 2.45
k_{2} = 0.000350, α2 = 2.10, β2 = 2.33.
Following this approach, to estimate the losses at a square wave excitation, we need to run Transient Magnetic analysis with a square wave source, and at the moment when the fluxes are at their maximums integrate the volume losses across the parts of our interest.
This may be easily implemented using Microsoft Excel and QuickField.
Results:
Magnetic flux density distribution at t = 2.5 ms (maximal values).
Total core loss is 19 mW.
Download simulation files
Video
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Reference:
^{1} Testing Core Loss for Rectangular Waveforms, Phase II Final Report, 21 September 2011 by Charles R. Sullivan and John H.Harris; Thayer School of Engineering at Dartmouth.
