Reluctance Force Actuator
Magnetomotive device based on reluctance force
Library
Magnetic Elements
Description
The Reluctance Force Actuator block models a generic magnetomotive device based on reluctance force.
The block is based on the following equations:
where
| F | Reluctance force |
| Φ | Flux in the magnetic circuit |
| Reluctance | |
| x | Thickness or length of the air gap |
| μ0 | Permeability constant |
| μr | Relative permeability of the material |
| A | Cross-sectional area of the section being modeled |
| u | Velocity |
Connections N and S are magnetic conserving ports, and connections C and R are mechanical translational conserving ports. The magnetic force produced by the actuator acts to close the gap, therefore the resulting force is negative when it acts from C to R.
Variables
To set the priority and initial target values for the block variables prior to simulation, use the Variables tab in the block dialog box (or the Variables section in the block Property Inspector). For more information, see Set Priority and Initial Target for Block Variables.
Basic Assumptions and Limitations
The current excitation in the system is constant.
Only axial reluctance is modeled.
Parameters
- Initial air gap
Thickness or length of air gap at the beginning of simulation. The default value is
2mm.- Minimum air gap
Minimal value of air gap, with the reluctance force acting to close the air gap. The parameter value has to be greater than 0. The default value is
1e-4mm.- Cross-sectional area
Area of the section being modeled. The default value is
0.01m^2.- Relative permeability of material
Relative permeability of the section material. The default value is
1.- Contact stiffness
Stiffness that models the hard stop at the minimum air gap position. The default value is
10e6N/m.- Contact damping
Damping that models the hard stop at the minimum air gap position. The default value is 500 N/(m/s).
Ports
The block has the following ports:
NMagnetic conserving port associated with the block North terminal.
SMagnetic conserving port associated with the block South terminal.
RMechanical translational conserving port associated with the rod.
CMechanical translational conserving port associated with the case.