ABSTRACT
Power quality (PQ) is an issue of high concern to the utilities when integration of the renewable energy (RE) level is continuously increasing in the utility grids. Various operational events, including feeder operation, load switching, capacitor switching, and operation of RE generators, affect the quality of power in the presence of RE. Signal processing approaches are being used for identification of the PQ issues in the network of utilities with RE penetration. In this paper, a method is introduced that makes use of the Stockwell transform (ST) and Hilbert transform (HT) to identify PQ issues in the utility grids with RE penetration. A PQ estimation factor (PEF) and a time estimation factor (TEF) are introduced for recognition and location of the PQ issues associated with the various operational events in the distribution system where a wind power plant (WPP) and solar power plant (SPP) are connected. Features are computed from PEF and TEF to classify the events in different categories. The proposed study is performed on a IEEE-13 nodes test system after integrating a WPP and a SPP in a MATLAB/Simulink environment. The performance of the method is better, compared to the discrete wavelet transform (DWT)–based method.
