Distance protection of shunt compensated transmission line using a sparse S-transform

In this study, the detection, classification and location of faults on a power transmission system operating with a Static Compensator (STATCOM). A cumulative sum average technique is used to detect the instant of the occurrence of the fault, while the energy of the important frequency components of the fault current is evaluated using a computationally fast frequency filtering S-transform (FFST) (sparse ST) to classify the type of fault. Furthermore, the new matrix version of the FFST is used to calculate the fault location, and fault trajectories along with a simplified fast Gauss-Newton algorithm. To validate the new formulation, different types of faults are initiated on a transmission system before and after the STATCOM using MATLAB/SIMULINK software and it is observed from the results that the FFST detects, classifies and locates the fault type accurately in most of the cases. The computational speed of FFST is almost 30 times higher than the conventional discrete ST to make it a likely candidate for real-time application. Practical verification of the proposed scheme has been attempted using real-time digital simulator platform.