Problems #7

1. Discuss a complete scheme for the control of LCI fed Wound Field Synchronous Machine drive with constant turn-off angle. Also explain how commutation overlap angle may be measured and utilized for such drive.

2. Explain with the help of phasor diagrams how reference-flux and reference-field-current commands may be estimated for a scalar control cycloconverter fed synchronous machine drive for operation at the unity power factor.

3. Compare the performance of vector controlled Induction motor drive with a vector controlled synchronous machine drive. Why the performance of the synchronous machine drive is sluggish and how this may be overcome? Discuss a complete scheme for a high performance speed control system for the wound field synchronous machine drive with programmed power factor.