Fundamental Reluctance

Simplified implementation of magnetic reluctance


Magnetic Elements


The Fundamental Reluctance block provides a simplified model of a magnetic reluctance, that is, a component that resists flux flow. Unlike the Reluctance block, which computes reluctance based on the geometry of the section being modeled, the Fundamental Reluctance block lets you specify a value of reluctance directly as a block parameter.

The block is based on the following equation:



MMFMagnetomotive force (mmf) across the component
ΦFlux through the component

Connections N and S are magnetic conserving ports. The mmf across the reluctance is given by MMF(N)MMF(S), and the sign of the flux is positive when flowing through the device from N to S.

Dialog Box and Parameters

Parameters Tab


The ratio of the magnetomotive force (mmf) across the component to the resulting flux that flows through the component. The default value is 8e4 1/H.

Variables Tab

Use the Variables tab in the block dialog box (or the Variables section in the block Property Inspector) to set the priority and initial target values for the block variables prior to simulation. For more information, see Set Priority and Initial Target for Block Variables.


The block has the following ports:


Magnetic conserving port associated with the block North terminal.


Magnetic conserving port associated with the block South terminal.

Introduced in R2014a

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