Lamination material anisotropy and its influence on the operation of inverter-fed induction machines

In modern inverter-fed machines the exploitation of the transient electrical behavior becomes of increasing interest to obtain additional information on the machine state with speed sensorless flux/rotor position detection schemes or fault condition methods. In the application of these methods it turned out that the anisotropy of the lamination material, which is usually negligible in the fundamental wave behavior of the machines influences the transient control signals and may act as a disturbance during operation. In this paper the anisotropy is determined by hysteresis and torque measurements of lamination sheet as well as by the evaluation of the transient electrical behavior of industrially manufactured inverter fed induction machines.