Inter-harmonics analysis method based on particle swarm optimization algorithm

With the deterioration of harmonics pollution in power system, it is of great importance to accurately find out the harmonics component for the safe and economical operation of the power system. To effectively detect the harmonics and inter harmonics in electrical signals, an input matrix is built with series of time delay sampling signals. The waveform of each component can be obtained by independent component analysis (ICA) based on maximum likelihood estimation, and frequencies of the fundamental wave, harmonics and inter- harmonics in signal can be obtained also. Using these values as initial condition, particle swarm optimization (PSO) algorithm is run and the amplitude and phase of each component consisting of the signals are accurately computed. Matlab simulation results show that this method is more accurate to analysis inter-harmonic parameters, especially to the inter-harmonics between closer frequency, still be able to accurately analyze their parameters.