ACElec3: Slot Insulation

End part of the rotor winding of the turbine generator

Problem Type:
A plane-parallel problem of AC conduction.

Geometry:
Slot insulation electric stress To reduce the field intensity along the surface of insulation the semi-conducting SiC lacquer is applied. Insulation Conductor Rotor (grounded) Coating SiC lacquer

Given:
Relative permittivity of coating ε = 4.
Relative permittivity of insulation ε = 3.
Relative permittivity of SiC lacquer ε = 4.
Conductivity of coating g = 10-4 S/m;
Conductivity of insulation g = 10-10 S/m;
Conductivity of SiC lacquer g = 10-8... 10-5 S/m;
Frequency f = 50 Hz;
Voltage Uf = 15000 V;
Breakdown voltage E = 25 kV/mm.

Problem:
In the overvoltage test the voltage U = 2Uf + 5 kV is applied. The field intensity along the surface of insulation should be less then ES < 0.5 kV/mm. To reduce ES value the special semi-conducting SiC lacquer is applied. Determine the distribution of the field intensity along the surface of isolation.

Results:

See the ACElec3.pbm problem in the Examples folder.