Mitigation of secondary arc current in monopolar recloser operation in single and double Extra High Voltage lines with application in Ecuador -Perú Interconnection 500 kV

Abstract

In   the   occurrence   of   a   single-phase   fault   in   a transmission  line,  the  existence  of  two  currents  is considered:  the  first one the  Primary  Arc  Current resulting  from  the  failure  and  the  second one,  the Secondary  Arc  Current  that  may  arise  from  the opening   of   the   phase   in   failure   by   automatic protections action.

Mitigation of Secondary Arc Current (SAC) is a taskof great incidence to obtaining a successful monopolar recloser operation in extra high voltage (EHV) lines. This research explores the main technologies and the  methodology  to  mitigate  the  secondary  arc  current. After, the  ideal  technologic  solutions,  based  on  the Ecuadorian  System  characteristics,  are  selected  and studied.  As part  of  the  research,  the  mathematical formulation  to  characterize  the  capacitive  couplings and  their  neutralization  through  parallel  inductive compensation and reactors (inductors) in the neutral of banks of three-phase reactors is presented.

A suitable  methodology  is  established  to  achieve  the goal of  mitigating or  reducing SAC in the event of a single-phase  failure. In  order  to  evaluate  the  results and  verify  the  benefits  of  the  procedure,  the  future interconnection double circuit Ecuador - Peru 500 kV has been selected as application example.