Research On The Improved Harmonic Detection Method Based On Instantaneous Reactive Power Using Mathematical Morphology

With the development of modern industrial technology and power electronic technology,harmonic pollution became more and more serious,because the nonlinear devices widely used in the power system.Harmonic in the power system will make a lot of negative effects on power system and power equipment.The harmonic detection method based on instantaneous reactive power theory has become the mainstream algorithm of current harmonic current detection,because of simple detection circuit and clear physical meaning.How to improve the performance of harmonic detection algorithm will be great significance.The main contents of this paper are as follows:Firstly,the paper introduces the generation and harm of harmonics and the importance of harmonic detection.Then it summarizes development and research status of harmonic detection and mathematical morphology.Secondly,the paper analyzes the basic theory of instantaneous reactive power,the p?q and the ip-iq detection method is studied.The suitable filter parameters can be selected by comparing different order and different cut-off frequency of low pass filter.Thirdly,the paper introduces the basic concepts of mathematical morphology basic operation.The frequency response of the structural elements used in this paper is analyzed in detail.Then the theoretical length of the structure element is determined by the sampling frequency and the filter cut-off frequency.Lastly,combining with the S function,the realization steps of the morphological filter are given.The ip-iq harmonic detection method is improved by mathematical morphological filter.The simulation and experimental results verify the effectiveness of the algorithm.