In operation of the generators

electrical field strength in the passage of the stator bar

between the stator bar and the tank wall

or on the insulation of the coil’s surface is uneven.When the electrical field strength reaches a critical level

the corona phenomenon arises.What’s more

under the affection of electric field

when the working voltage reaches the discharging voltage

partly discharging will happen in the gap of the coil.So

the electric field’s calculation in coil slot is of great importance.This article introduces the basic principle of finite element.Using the large-scale generator stator trough as the analysis model and a professional finite element analysis software-ANSOFT for the electric field analysi.