Bus Type - Known Parameter - Unknown Parameter Load Bus -P, Q - V, phase angle Generator Bus - P, V (magnitude) - Q, Voltage phase angle Slack Bus Voltage - magnitude and phase angle - P, Q
For lagging power factor = (IR*cosφ + Ixsinφ)/Vr For leading power factor = (IR*cosφ - Ixsinφ)/Vr Zero voltage regulation occurs on leading power factor only.
The connection of CT on primary and secondary side is always reverse to the connection of transformer. To protect the power transformer with star-delta against fault, the type of connection of CTs should be in the delta–star connection otherwise the relay will operate when an external fault occurs due to zero sequence currents
EXAMIANS