Overcurrent Relay Setting Model for Different Fault Location in Transmission Line
K Thi Soe #1, May Than Naing *2,
#Department of Electrical Power Engineering, West Yangon Technological University,Myanmar
The fault is a major problem in a power system network. The demand of electric power, the transmission is increasing year by year and therefore maintenance and protection of power system equipments. The line protection is very important aspect when we consider the safety of the power system as it is used to transfer bulk power from one area to other. Various protection schemes are used to protect the transmission line like over-current protection, distance protection, etc. EHV/HV long transmission transmits large power.it is very important to clear any fault occurred in the transmission line. The protective relay operates when internal and external fault is occurred in power system. The aim of this paper is the relay which operates through the faults in accordance with setting value of relay plug setting multiplier (current setting) and time multiplier setting. The main objective of this paper is to design a computer based model using characteristics equation of overcurrent relay (Standard Inverse) for determination of different fault locations. This paper also present the relay setting and coordination of a 230/66/11kV typical substation with expected short-circuit. The result of the actual operating time and time multiplier setting (TMS) of overcurrent relay are determined.
Keywords - Symmetrical & Unsymmetrical fault, overcurrent relay, relay setting.