Parametric Estimator-based Algorithm for Smart Monitoring of Harmonics/Inter-harmonics in ADN

The increasing power electronics-based equipment has aggravated the inter-harmonics distortion level in the active distribution network (ADN), challenging the accurate monitoring of harmonics/inter-harmonics with time-variant frequencies and amplitudes. To cope with this issue, this paper proposed a novel method for accurate and timely monitoring of harmonics/inter-harmonics in the modern ADN. Firstly, an adaptive parametric estimator (PE) method is presented with rigorous math derivations, where decoupled selections of data window width and model orders are achieved. Then, a novel algorithm is proposed utilizing the features of the PE method above, which properly select the estimation rate and model orders according to practical monitoring requirements. Afterwards, the proposed method is tested using field measured data from an actual ADN in China. The results validate the accuracy and robustness of the proposed method, which demonstrates the capability of its future application in practical monitoring of the power grid.