A Complete Analytical Theory of Self controlled Inverter Fed Synchronous Machine

A natural commutation inverter fed salient pole synchronous machine, with dampers in both axes is considered. Complete expressions are given for the currents during both the conduction and commutation intervals; they are based on the evaluation of the eigenvalues and eigenvectors of the equations which are derived from Park's model. All resistances are taken into account, for any value of frequency. It is shown how to determine the lower frequency at which natural thyristor turn-off can occur. An experimental method is proposed to find experimentally the lower frequency limit of operation.