Abstract Multi-purpose grounding of secondary neutral point N600 of voltage transformer in transformer substation may cause distance protection, zero sequence protection rejection or misoperation. An on-line monitoring device for secondary neutral point N600 (PTN600) of voltage transformer in substation is developed, through software programming, hardware reasonable setting and coordination. It realizes the real-time monitoring of the ground condition of the PT secondary neutral line N600 in the substation, and triggers relevant warning information in time when multi-purpose grounding occurs in N600. The hidden safety hazards are found to avoid the malfunction of the fault protection device outside the zone. The fault protection device in the zone is rejected, so as to ensure the safe and stable operation of the power grid and improve the work efficiency.
2019, Vol. 20 
