The results show that grooves on magnetic pole surface can change the magnetic field distribution effectively and enhance the grade of magnetic field,so the higher finishing efficiency can be obtained.

The third damp bars of some magnetic poles on the bulb type hydrogenerators in Feilaixia Hydropower Station regularly broke.

Magnetics is one of the foundations in elementary physics education from which emerge some specious problems such as the mutual actions between magnetic poles, the distinction of permanent magnet polarity and the description of magnetic induction line.

The technological process of the new and old die forging for the pole was described.

This paper introduces the main design differences between the poles of Three Gorges Generator and the traditional one and as well the structures and the merits of the pole without press plate,chain wedge etc which are the new structures used in Three Gorges Generator by ALSTOM Power Ltd.