Determination of damper winding and rotor iron currents in convertor- and line-fed synchronous machines

The damper winding currents of a synchronous machine with a solid iron rotor are analyzed. Based on the self and mutual inductance modelling technique, the damper currents are described by a detailed damper model taking the damper cage and the rotor iron into account. The model´s component elements are determined by the finite element method. Theoretical results are verified by measuring damper bar currents of a six-phase synchronous machine fed by two six-pulse converters. For a number of different operating modes the model is used to calculate the damper current distribution of a six-phase machine