Electromagnetic plunger

QuickField simulation example

Electromagnetic plunger works on AC current and consists of the coil with moveable core. Core position is controlled by the external spring.

Problem Type
Axisymmetric multiphysics problem of AC magnetics coupled to Stress analysis.

Geometry

Given
Coil has 500 turns with current 1 A.
AC frequency 50 Hz.
Plunger is made of steel with relative permeability μ = 1000
Steel's Young modulus 200 GPa.
Spring has the rigidity coefficient 50 N/m.

Task
Estimate the plunger displacement at the given current.

Solution
Two QuickField problems are created which share the same geometry. Stress analysis simulation is coupled to the AC magnetic analysis to import the magnetic forces acting on the plunger. Spring is taken into account by use of the special boundary condition in the Stress analysis problem assigned to the vertex of the model where the spring touches the core body.
Stress analysis should be performed on the plunger alone, other parts of AC magnetic model do not need to be included.

Result
Plunger displacement is -0.7 mm.
Magnetic field distribution and plot of the displacement of the moveable plunger

• Video: Electromagnetic plunger. Watch on YouTube
  
• Download simulation files (files may be viewed using any QuickField Edition).