Question

A synchronous motor can be made to operate either at the lagging or unity or leading power factor?

Answer 1

Answer:

Synchronous motors are designed to operate at unity (1.0) power factor or 0.8 leading power factor. By varying the DC excitation of the motor, the power factor of the motor can be varied widely. Overexcited synchronous motors operate at leading power factor and provide reactive kVAR-like capacitors. It can be made to take a leading current with over-excitation of its field winding. One of the major and unique characteristics of this motor is that it can be operated at any electrical power factor leading, lagging or unity and this feature is based on the excitation of the synchronous motor