Q1Power System - I
Question
Q.1. What is the need of grounding the neutral in power system?
Answer
The neutral is grounded to limit overvoltages during earth faults, provide a path for earth-fault current so protective relays can detect and clear the fault, and stabilize the system voltage with respect to ground.
Grounding (earthing) the neutral point of a power system serves several purposes: it limits the transient and steady-state overvoltages on healthy phases during a single line-to-ground fault (an ungrounded system can develop overvoltages up to 3 times normal on healthy phases); it provides a low-impedance return path for earth-fault current, enabling protective relays and earth-fault relays to detect and selectively clear the fault quickly; it stabilizes the phase voltages with respect to earth, preventing the neutral point from floating to dangerous potentials; and it reduces electrical stress on insulation, permitting the use of lower insulation levels and hence economical equipment design.