In an induction motor, magnetic flux in the axis direction, such as leakage flux in the coil end, can have a large effect on motor characteristics. However, transient phenomena are strong in the inductance motor, and analysis time is needed in order to achieve a steady state solution. Due to this, being able to evaluate characteristics in a 2D analysis is desirable, but 3D effects such as leakage flux in the coil ends are ignored in a 2D analysis, and there are cases when an accurate analysis cannot be obtained. In JMAG, highly accurate results can be quickly obtained by performing corrections on 3D effects.
This document introduces introduces a case study which obtains inductance correction values, and then obtains N-T characteristics (revolution speed-torque characteristics) using the 3D correction function.
Fig.1 shows that inductance has decreased by approximately 25% in a 2D analysis when compared to a 3D analysis. This is because a 2D analysis cannot account for leakage inductance in the coil end.
Fig.2 shows those N-T characteristics of 2D, 3D and 2D analysis with 3D correction and fig.3 shows N-I characteristics.
Fig. 2 shows that N-T characteristics becomes the same as 3D by using 3D correction. As shown in fig.3, this is because current flowing in the coil has come closer by accounting for leakage inductance.