Relay dynamics simulation using Ruby and QuickField Object Model - QuickField simulation example
Relay-plunger motion under electromagnetic and spring forces, with Ruby integrating the motion equation and obtaining electromagnetic force at each position..
To combine the electromagnetic field analysis with the moving core dynamics both Ruby and QuickField are used. Interaction between QuickField and Ruby is performed using ActiveField application programming interface.
How is the relay's plunger motion calculated using QuickField and Ruby?
Answer Typical applications Geometry
Given
Task
Solution
The motion function can be found from second-order differential equation
The equations are solved in Ruby. The dynamic link through COM is used to invoke QuickField and calculate the electromagnetic force at each step.
The calculations are stopped when x=xmin (pull in position, plunger hits damper).
Results
Engineering question
Set up an axisymmetric QuickField DC Magnetics problem and replace the multi-turn coil with an equivalent total current. Use Ruby (via COM/ActiveField) to integrate the plunger's equation of motion, invoking QuickField at each step to get the electromagnetic force.
electromagnetic relays, relay armatures, electromechanical switching devices
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Simulation problem
Problem Type
Axisymmetric problem of DC magnetics.
Current I = 400 Ampere*turns;
Plunger pull-out position xmax = 10 mm.
Plunger pull in position xmin = 6 mm.
Plunger weight m = 4.5 g;
Spring constant k = 4 N/m
Spring free position xspring.free = 15 mm.
Relay-plunger motion under electromagnetic and spring forces, with Ruby integrating the motion equation and obtaining electromagnetic force at each position..
The multi-turn winding is replaced with the equivalent total current.
m · d²x/dt² = f(x),
where m - is a plunger weight (kg),
x - is a plunger position (m)
f(x) - is the force acting on the plunger (N).
The force acting on the plunger is a sum of spring force fspring(x) = k·(xspring.free - x) and electromagnetic force.
The plunger hits initial position at 0.075 s.
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