In this paper

a kind of detection method for the filter based on PSO algorithm is proposed.Its principle is to derive the calculation formula of filter impedance through the filter structure and set up equation in accordance with the impedance of the filter at different harmonics which is obtained by actual calculation.The non-linear equation system is solved by PSO optimal algorithm so to get the real value of each element and achieve the purpose of online detection for the different elements of filter.The proposed method is simple and feasible without site modification of the filter

has important significance for the safe operation of the filter.The correctness and effectiveness of the proposed method is verified by the simulation.