Influence of Magnetic Slot Wedge on Parameter and Loss Distribution of High Voltage Induction Motor

Owing to the stator open slot structure of the high-voltage motor, the magnetic field distribution in the motor will be uneven, and the performance of the motor will deteriorate. When the slots are embedded with magnetic material slot wedges, the magnetic field of the motor will be changed. In this article, taking a 10 kV/1000 kW high-voltage induction motor (HVIM) as the prototype, the two-dimensional finite element models are established, the effect of magnetic slot wedge (MSW) on HVIM was analyzed. First, by establishing the air-gap permeance function, the influence of magnetic slot wedge on the air gap magnetic field is analyzed, the influence mechanism of magnetic slot wedge on tooth harmonic magnetic field is revealed. In addition, the effect of magnetic slot wedge on excitation inductance, slot leakage resistance, and winding inductance of HVIM is analyzed in detail, the variation of parameters with different relative permeability of slot wedge is summarized, the changes in the motor starting performance had further discussed. Finally, the influence of the slot wedge permeability on motor losses is studied, the distribution of core loss is obtained by establishing the motor segmenting model, and the various mechanisms of core losses in different regions are revealed. The findings provide the guidelines and theoretical basis for the rational selection of magnetic slot wedges.