A voltage dip is a short temporary drop in the voltage magnitude in the distribution or customer's electrical system. Common causes of voltage sags and under voltages are short circuits (faults) on the electric power system, motor starting, customer load additions and large load additions in the utility service area. Sags can cause computers and other sensitive equipment to malfunction or simply shut off.
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.