Fault Analysis and Fault location in Fuseless split-wye shunt capacitor banks

Abstract

Shunt capacitor banks (SCBs) play a vital role in the electrical industry as a reactive power compensator and improvement of voltage-efficiency profile. The failure of the shunt capacitor banks cause unbalances to the power and voltage profile of the system. The time taken to physically locate the fault place in bank is large and troublesome and hence reduces the efficiency of the system. The following paper focuses the method of fault location in high voltage shunt capacitor banks using the technique of neutral current compensation method and also provides detailed fault analysis of the capacitor bank. This paper covers Fuseless SCBs. The investigation will focus on identification of single capacitive faulty element in the capacitor bank. The paper employs the un-grounded double wye configuration, which is the technically more suitable for fault detection. The technique efficiently applicable for grounded, un-grounded, even and un-even capacitor bank configurations. The investigation relies on a comprehensive mathematical modeling of capacitor bank. The results are tabulated using IEEE Std C37.99-2000.The tabulated results are in per-unit values, hence the following technique not only removes the problem of complex series –parallel capacitance calculations, but also easier to understand and apply. The ratio between neutral compensation current and corresponding phase current will lead us towards faulty element location