Start-up of large-power synchronous motor with the 6 kV voltage source inverter and microprocessor-controlled unit for excitation supply

The paper presents idea and practical implementation of a medium voltage synchronous drive with a voltage source inverter in the stator circuit and a microprocessor controlled unit for excitation supply. Construction of both devices was presented, and methods of their cooperation were described. Selected start-up methods of large power synchronous motors were presented. Exemplary realization was discussed. Measurement results of the direct full-voltage start-up and frequency start-up of a real 1.25 MW 6 kV fan drive system were compared and discussed.