TRAVELING-WAVE EXCITATION OF NONLINEAR MAGNETIC-MATERIALS OF SIGNIFICANT CONDUCTIVITY

The travelling wave excitation of semiinfinite and finite thickness st eel plate is examined using a multilayer electrical circuit concentrat ed parameter analogue to represent the electromagnetic field equations . Normalised characteristics of surface impedance and power input for steel plate with finite resistivity and constant permeability show tha t the method gives reasonably accurate results. The method is then ext ended to represent magnetic material which includes both hysteresis an d eddy current action using a digital simulation technique, previously described. Computed values of the fundamental surface impedance and p ower input are determined for magnetically semihard and hard materials . Field patterns inside the material are illustrated. Some experimenta l results on locked rotor machines validate the predicted values.