Identification of fault and load increase to prevent distance relay mal-operation: article / Faten Hamima Ismail

Distance relay mal-operation has been identified as one of the factors of blackouts in the world. One of the causes that lead to this problem is distance relay cannot differentiate between fault occurrence and load increase in transmission lines. This paper presents a proposed method to identify fault occurrence and load increase in transmission line to prevent distance relay mal-operation. The analysis of instantaneous voltage and root mean square (RMS) voltage signal waveform measured at the corresponding buses are used to differentiate the characteristics between two of them. The proposed technique is designed and validated through simulations of IEEE 9 bus test system in PSCAD and the plots of the voltage waveform using Microsoft Excel. The results show that there are different characteristic of voltage waveform that can clearly indicates fault occurrence and load increase.