Fault Detection in Series Compensated Lines in the Presence of Power Swings Using Sum of Negative and Zero-Sequence Voltages

Abstract

The distance relays misinterpret power swings as fault like situation and produce undesirable tripping signals. So, the action of these relays is bypassed for power swing conditions. Distance relays are equipped with features like power swing blocking and out-of-step operation functions to deal with such situations. Although, the fault in the presence of the power swing can be identified, but to detect the faults when power swing is present in a series compensated line is quite problematic because of the issues related to effects generated by the series capacitor and its protection aspects. This paper introduces a technique that uses the sum of negative sequence and zero-sequence voltages to identify the faults in the presence of the power swings in a series compensated line. Various types of faults like fault involving single phase or two phases or all the phases incorporating high fault resistance are simulated using this technique in MATLAB from the data generated by simulating the system in EMTDC/PSCAD to test the proposed technique.