Evaluation of wind farm harmonic emission level based on parameter adaptive FastICA

Abstract

The harmonic impedance at the wind farm side may not be much greater than the harmonic impedance at the system side due to the fan filter and reactive power compensation equipment. Therefore, the influence of the impedance at the wind farm side cannot be ignored when evaluating the harmonic emission level. A method for estimating harmonic impedance of system side based on parameter adaptive FastICA is proposed. According to the independence of the fluctuation amount of the harmonic sources on both sides of the PCC point, the parameter adaptive FastICA method is used to extract the independent components, and the least square method is used to solve the mixed matrix, and then the harmonic impedance on the system side is obtained. The approximate value of the harmonic impedance at the wind farm side is calculated through the parameters of the wind farm elements, and the influence of the harmonic impedance at the wind farm side is considered to evaluate the harmonic emission level. This method does not need to select the activation function according to the prior information of the probability density of the source signal, and has better separation effect of the source signal and anti background harmonic interference ability. The effectiveness of the proposed method is verified by simulation and measurement.