Reluctance Force Actuator

R2026b

Magnetomotive device based on reluctance force

• 

Reluctance Force Actuator block

To add a block to a model, double-click the canvas and start typing the block name. Then, select the block from the list.

Libraries:
Simscape / Foundation Library / Magnetic / Magnetic Elements

Description

The Reluctance Force Actuator block models a generic magnetomotive device based on reluctance force.

The block uses the equations

$$F=-0.5\cdot {\Phi }^2\cdot \frac{d\Re }{dx}$$

$$\Re (x)=\frac{x}{{\mu }_0\cdot {\mu }_r\cdot A}$$

$$u=dx$$

where:

• F is the reluctance force.

• Φ is the flux in the magnetic circuit.

• $$\Re$$ is the reluctance.

• x is the thickness of the section being modeled, or the length of air gap.

• μ₀ is the permeability constant.

• μ_r is the relative permeability of the material.

• A is the cross-sectional area of the section being modeled.

• u is the 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 Initial Targets section in the block dialog box or Property Inspector. For more information, see Set Priority and Initial Target for Block Variables.

Nominal values provide a way to specify the expected magnitude of a variable in a model. Using system scaling based on nominal values increases the simulation robustness. Nominal values can come from different sources, one of which is the Nominal Values section in the block dialog box or Property Inspector. For more information, see Modify Nominal Values for a Block Variable.

Examples

Solenoid with Magnetic Blocks

Model a solenoid with spring return. When unpowered, the spring pulls the plunger +5mm away from the center of the coil. Turning on the power supply at t=0.1 seconds pulls the plunger into the center of the coil. At t=0.3s, a 10N external load is added to the plunger.

• Open Model

Permanent Magnet Attached to Iron Wall

Model the forces acting on a magnet that is attached to an iron wall. You can define the interaction between the magnetic and translational motion domains using a Permanent Magnet block and a Reluctance Force Actuator block.

• Open Model

Model Oscillation Sensor Using Permanent Magnet Block

Model an oscillation sensor using the Permanent Magnet block. The sensor consists of a magnetic core with a permanent magnet that generates a magnetic field, a ferromagnetic plate attached to the core, and a conducting winding around the core.

• Open Model

Ports

Conserving

N — North terminal

magnetic

Magnetic conserving port associated with the north terminal.

S — South terminal

magnetic

Magnetic conserving port associated with the south terminal.

C — Case

electrical

Mechanical translational conserving port associated with the case.

R — Rod

electrical

Mechanical translational conserving port associated with the rod.

Parameters

Initial air gap — Thickness or length of air gap at start of simulation

2 mm (default) | positive scalar

Thickness of the section being modeled, or length of air gap, at the beginning of simulation.

Minimum air gap — Minimal allowed value of air gap

1e-4 mm (default) | positive scalar

Minimal value of air gap, with the reluctance force acting to close the air gap.

Cross-sectional area — Cross-sectional area of section being modeled

0.01 m^2 (default) | positive scalar

Cross-sectional area of the section being modeled.

Relative magnetic permeability of material — Relative magnetic permeability

1 (default) | positive scalar

Relative magnetic permeability of the section material.

Contact stiffness — Stiffness of hard stop

10e6 N/m (default) | positive scalar

Stiffness that models the hard stop at the minimum air gap position.

Contact damping — Damping of hard stop

500 N*s/m (default) | positive scalar

Damping that models the hard stop at the minimum air gap position.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2010a