Application of S-Transform for voltage dips detection and analysis in modern distribution grids

The paper addresses the problem of fault detection and analysis in modern distribution grids, using an algorithm based on Stockwell transform (S-transform). The FFT and the Standard RMS were implemented for comparison of results with the ST method. Modified IEEE model of 13-bus test system with high level of distributed generation was used for testing of presented methods in Matlab/Simulink simulation environment. Methods are implemented in laboratory using advanced, dSpace based setup that includes modified industrial converters and distribution grid emulator. Also, real grid measurement results of voltage disturbances obtained on two different voltage levels are used for further testing of presented methods and confirmation of results obtained in simulations and on the laboratory setup.