The Co Energy
magnetic stored energy is a state function, determined uniquely by the values
of the independent state variables λ and x
Coenergy: Here the
force can be obtained directly as a function of the current. The selection of energy or coenergy as the
state function is purely a matter of convenience.
magnetically-linear system, the energy and coenergy (densities) are numerically
acts in a direction to decrease the magnetic field stored energy at constant
flux or to increase the coenergy at constant current. In a singly-excited
device, the force acts to increase the inductance by pulling on members so as
to reduce the reluctance of the magnetic path linking the winding.