The electro magnetic energy conversion is given by Ampere's law and Faraday's law respectively:
In this equation
is the magnetomotive force that is supplied to the connected
magnetic circuit,
is the magnetic flux through the associated branch of this
magnetic circuit. The negative sign of the induced voltage
is due to Lenz's law.
The static inductance is calculated from the flux linkage
and the current
:
This quantity is calculated for information only.
is set to
if
.