TITLE:
Impacts of Water-Tree Fault on Ferroresonance in Underground Cables
AUTHORS:
Bin Sun, Elham Makram, Xufeng Xu
KEYWORDS:
Ferroresonance, Water Tree, PSCAD, COMSOL, Overvoltage
JOURNAL NAME:
Journal of Power and Energy Engineering,
Vol.5 No.12,
December
18,
2017
ABSTRACT: Nowadays, more and more electrical power is being distributed to customers by underground cables rather than overhead transmission lines due to their advantage of providing better protection in inclement weather. They also have significantly reduced electromagnetic field emission because of their copper shielding. But underground cables have larger capacitance than transmission lines per unit. Thus, ferroresonance is more likely to occur in distribution systems using underground cables. Moreover, soil humidity at a depth of one meter remains 100 percent for most of the year, a factor that risks the occurrence of water tree (WT) in cables. Consequently, both ferroresonance and WT are prone to occur in underground cable systems. The objective of this paper is to determine the relationship between ferroresonance and water tree. A test system was designed to simulate and analyze ferroresonance in a cable system caused by single-phase switch and water tree. Eight scenarios of water tree were compared in the simulation. There sponses of ferroresonance are presented in this paper and two common patterns are observed from the simulation results.