In this system, the neutral is earthed either directly or through resistance or reactance depending on the requirement. Thus the system neutral can be grounded effectively or non-effectively. In effectively grounded system, the neutral is grounded directly and hence it is called solid grounding. Following methods are adopted for non-effectively grounded systems.
i) Resistance earthing
ii) Reactance earthing
iii) Arc supression coil or resonant earthing
iv) Voltage transformer earthing
v) Earthing transformer
The advantages of neutral earthing are as follows,
i) The arcing grounds are prevented from occurring by employing suitable switchgears.
ii) As the neutral point is not shifted in this system, thus the voltages of healthy phases remains nearly constant.
v) The magnitude of transient voltage is small in this system.
vi) The discriminative type fault indicator can be installed on such systems.
iii) The static charges which are induced are grounded immediately and are thus prevented from causing any disturbance.
iv) The faulty part of the system can be isolated from the remaining system with the help of earth fault relays.v) The magnitude of transient voltage is small in this system.
vi) The discriminative type fault indicator can be installed on such systems.
vii) This system is more reliable, provides safety to personnel and equipment with reduced operational and maintenance cost than ungrounded system.
