Detection and analysis of power system faults in the presence of wind power generation using stockwell transform based median

Recently, the distributed generation (DG) has emerged as important source of energy which is capable to meet our future energy demand. These generators with large capacity are integrated into the power system network. Integration of DG sources to the utility networks changes network behavior causing different effects on the system such as power quality problem, protection issues, and stability issues. These issues need to be investigated separately. Protection of the utility network in the presence of DG sources is a challenging task which needs to be investigated. Integration of DG units to power system networks affects behavior of protection and relaying equipment due to widespread distribution of these units and variable generation from these units. Hence, to provide an accurate protection system against various types of faults in the power system network, such as line to ground (LG), double line (LL), double line to ground (LLG), and three-phase to ground fault (LLLG), effective detection, as well as discrimination of faults from each other, is essentially required. This work presents an algorithm based on the median calculated from the S-matrix obtained by decomposition of current signal using Stockwell transform to detect faults in power system network incorporated with wind generator. The proposed algorithm is based on detection of the faults using the threshold values. The proposed study is performed in MATLAB/Simulink environment using IEEE-34 node test system incorporated with wind generator.