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
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.
Carrier current over the power line provides simultaneous tripping of circuit breakers at both ends of the line in one to three cycles. Thereby high-speed fault clearing is obtained, which improves the power system stability. The auto-reclosing simultaneous reclosing signal is sent thereby simultaneous (1 to 3 cycles) reclosing of the circuit breaker is obtained. For simultaneous faults, carrier-current protection provides easy discrimination.
As per answer key "pilot protection" is true but there is mistake the right answer is "none".
Simple logic of reactance diagram is that simplified equivalent circuit of power system in which the various components of power system are represented by their reactance. The reactance diagram can be obtained from impedance diagram if all the resistive components are neglected. So, from figure each of the component is represented by its reactance.
EXAMIANS