A comprehensive analysis and solution for sympathetic tripping in distribution network

Abstract

The objective of this paper is to provide a comprehensive analysis and solution for sympathetic tripping in distribution network. Al Ain Distribution Company (AADC) is responsible to operate and maintain the power distribution from 0.415 kV up to and including 33 kV level in the eastern region of Abu Dhabi emirate. AADC is always keen to provide safe and secure power supply to its customers. This paper analyses the sympathetic tripping problems and provides solution using an economical, safe, secure, and reliable scheme with utmost care, in order to minimize the damage to equipments and ensure continuity of power supply to customers as far as practicable in AADC network. The scheme is developed in combination of overcurrent, under voltage and negative sequence functions, which are readily available in numerical protection relays. The solution provided in this paper not only analyses modern relays/schemes, but also the possibility of improving existing protection scheme problems, where electromechanical relays are available with required modification without major cost impact.

Sympathetic Trip Analysis in Distribution System of PLTU and PLTA Nagan Raya

“…On the other hand, the Inverse Time Relay operates with varying times depending on the magnitude variation of the fault current. Based on the steepness of the curve, Inverse Time is further divided into Standard Inverse Time (SIT), Very Inverse Time (VIT), and Extremely Inverse Time (EIT) [7].…”

“…The occurrence of voltage dips can range from 0.1 s to 0.3 s, and Transient Over Voltage can occur in 0.001 s, and the direction of current flow will head to the point of fault. This implies that feeders that are left undisturbed may still trip [7]. This occurs because the installed system in the power distribution still uses a non-directional Over Current Relay / Ground Fault Relay and the protection coordination is not yet sufficient [8].…”

Field experience with sympathetic tripping in distribution networks: problems and solutions

“…The flow of capacitive discharging currents in the healthy feeders when an adjacent feeder gets grounded in a resistance‐grounded or in the isolated‐neutral system is another reason for sympathetic tripping [5]. Referring to Fig.…”