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.