Determination of Fault Location in Shunt Capacitor Bank through Compensated Neutral Current

Abstract

Shunt capacitor bank in power transmission are essential in providing reactive power support and improvement of voltage profile at any required point within the grid system. The failure of shunt capacitor bank due to unbalance capacitance caused reactive power and voltage losses to the power transmission network. The time taken to identify the location of capacitance failure require a lot of time due to no physical indication failure in shunt capacitor bank. This paper is focused on investigating the fault location in shunt capacitor bank in high voltage system mainly at power system transmission through compensated neutral current method.The investigation is focused on the internal failure of capacitor unit in shunt capacitor bank which caused by capacitance element failure. The configuration of shunt capacitor bank applied in this research used the common type of configuration which is ungrounded double wye connection and internally fused type of capacitor unit. This type of shunt capacitor bank configuration will affect the development of mathematical modelling as the algorithm for identifying the location and number of element failure in shunt capacitor bank. The investigation is done by developing the mathematical modelling and simulation through MATLAB software for neutral current at the neutral point of shunt capacitor bank. The output results of neutral current are used to determine and identify the location and number of element failure in shunt capacitor bank. Through neutral current result, the angle of neutral current is compared with corresponding or equivalent phase current to determine the faulty section thus determine the location of element failure in shunt capacitor bank. The ratio between neutral current and equivalent phase current will determine the number and type of element failure occurred in a section of shunt capacitor bank. The comprehensive analysis was done to determine the relationship between number and type of element failure to the number and type of faulty capacitor unit in shunt capacitor bank.