Engee documentation

Reluctance Force Actuator

Interface between magnetic and mechanical progressive networks.

reluctance force actuator

Description

The Reluctance Force Actuator unit represents the interface between magnetic and mechanical progressive networks.

The block is based on the following equations:

,

μμ ,

Where:

  • - magnetic force;

  • - flux through magnetic ports;

  • - magnetic resistance;

  • - thickness or length of the air gap;

  • μ - magnetic constant;

  • μ - relative magnetic permeability of the material;

  • - cross-sectional area of the modelled element;

  • - velocity.

Connections N and S are magnetic ports, and connections C and R are ports of mechanical translational motion. The magnetic force generated by the actuator tends to reduce the gap, so the resultant force is negative when it acts from C to R.

Key assumptions and limitations

  • The excitation current in the system is constant.

  • Only the axial magnetic flux is modelled.

Input

N - north terminal
magnetic

Magnetic port corresponding to the north terminal of the unit.

S is the south terminal
magnetic

Magnetic port corresponding to the south terminal of the unit.

C - housing

Mechanical progressive port corresponding to the housing.

R - stem

Mechanical progressive port corresponding to the stem.

Parameters

Initial air gap, m - initial air gap
`0.002 m (by default)

Length of the air gap at the beginning of the simulation.

Minimum air gap, m - minimum air gap
0.0000001 m (by default).

Minimum air gap value at which the gap is considered closed. The value of the parameter must be greater than 0.

Cross-sectional area, m² - cross-sectional area
0.01 m² (by default).

Cross-sectional area of the modelled element.

Relative permeability of material - relative magnetic permeability of material
1 (By default)

Relative permeability of material.

Contact stiffness, N/m - contact stiffness
`1000000 N/m (by default)

A stiffness that models the rigid stop at the position of minimum air gap.

Contact damping, N*s/m - contact damping
500 N*s/m (by default).

Damping that simulates a rigid stop at the position of minimum air gap.

Initial value of flux, Wb - initial value of magnetic flux
0 (By default).

Initial value of magnetic flux.

Initial value of MMF, A - initial value of magnetomotive force
0 (By default)

Initial value of magnetomotive force.

Initial value of force, N - initial value of force
0 (By default)

Initial value of force.

Initial value of relative velocity, m/s - initial value of relative velocity
0 (By default).

Initial value of relative velocity.

Examples