Standstill Frequency Response Test on a Synchronous Machine Extended With Damper Bar Measurements

Standstill frequency response (SSFR) test data from a salient-pole synchronous machine with reconfigurable damper winding are presented. In addition to the regular measurements, the damper bar currents are measured and used to obtain the stator-to-damper transfer functions. The test is performed three times with physically different damper winding configurations. An extension to the standard SSFR test analysis scheme is suggested, where the stator-to-damper transfer functions are included. The validity of the identified models is substantiated by comparison of the simulated and measured machine response to a drive torque step disturbance. It is found that the damper winding measurements can be incorporated in the analysis scheme to isolate the effect of the damper circuits. However, for a machine of the type studied, also the standard SSFR test procedure yields models that are accurate enough for power system studies.