A Precise Location Method of Power Quality Disturbances Based on Morphological Edge Detection

A precise location method of power quality disturbances was proposed to solve the background gradient problems originated from the periodic changes of power signals and the existing of various interferences in the process of sampling. The proposed method includes the adaptive selection of structuring element (SE) for morphological filter by using signal to noise ratio (SNR) as a standard to assess the filtering effect, Top-Hat transform of morphological gradient (MG) which is introduced to suppress background gradient, and the soft- thresholding quantitative method. The preliminary location results are achieved by Top-Hat transform of morphological gradient and the final location results are determined by the soft-thresholding values. Simulations of a variety of power quality disturbances have been carried out, which shows its enhanced location precision, outstanding anti- jamming ability and universal applicability.