The Harmonic Perturbation subnode is available at the global level from the context menu (right-click the Coil parent node) or from the Physics toolbar, Attributes menu. Use this feature to specify a harmonic perturbation for the coil excitation.

A harmonic perturbation can be specified only if the Coil excitation of the parent feature is Coil current or Coil voltage. In the first case, enter a Coil current Icoil (SI unit: A). The default is 1 A. In the second case, enter a Coil voltage Vcoil (SI unit: V). The default is 1 V.