Finite Element Analysis of the Local Heating in Turbo-generators under Steady-state Asynchronous Operating Conditions

The heat field in the rotor of turbo-generators under steady-state asynchronous operation is studied by a two-dimensional finite element analysis. The eddy-currents in the solid iron rotor parts are taken into account. The temperature, especially in the damper-winding bars, reaches height values for small slips also, so that the safe limit can be exceeded and insulation damaged. As a consequence the synchronous machine goes of duty.