Static VAr compensators for critical synchronous motor loads during voltage dips

The operation continuity of a critical synchronous motor load group subjected to momentary voltage sags can be enhanced by locally installing a static VAr compensator (SVC). A method is presented to determine the minimum capacitive SVC rating necessary for the system to be transient stable, and to apply a microprocessor based control of the SVC admittance for providing damping of the power oscillations. The results are validated by simulation of the full order nonlinear model of the drive and distribution system.>