Inductor inrush current stress - QuickField simulation example
AC voltage source is connected to the inductor. Then AC power is applied, inrush current may be considerably higher than regular, and corresponding magnetic forces may cause higher mechanical stresses in the inductor assembly.
How to find inrush current and mechanical stress in inductors?
Answer Typical applications Geometry Given
Task
Solution
Results
Engineering question
Set up an axisymmetric QuickField Transient Magnetics problem for an inductor and evaluate inrush current and mechanical stress from computed field results.
ferromagnetic core inductors, power inductors, surge-current inductors
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Simulation problem
Problem Type
Axisymmetric multiphysics problem of transient magnetics coupled to stress analysis.
Relative magnetic permeability of the steel core μ=2000;
Electric conductivity of the winding (copper) g = 56 MS/m;
Number of turns w = 600;
Applied voltage value (amplitude) U = 18√2 V;
Frequency f = 60 Hz.
Calculate the peak current value and mechanical stress in the inductor winding.
The current wave period is T = 1 / f = 16 ms. We choose the time step of 1 ms that guarantees a smooth time-plot. Nine periods are simulated (150 ms).
The peak current value is 1.8 A (+65% to the rated value) appears 7ms after switching the voltage on. The color map of mechanical stress in the coil is shown below.
Video
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