Tracking of voltage flicker in power distribution systems: A local polynomial modelling approach

This paper proposes a local polynomial modelling (LPM) approach for voltage flicker tracking problem in power systems. The estimation of voltage envelope can be regarded as the identification of a time-varying linear model (TVLM). The proposed LPM approach models the time-varying coefficients of the TVLM locally by polynomials, which can be estimated by least-squares estimation with a kernel having a certain bandwidth. A data-driven variable bandwidth selection (VBS) method is then proposed to estimate the optimal variable bandwidth for minimizing the mean squared error (MSE). Online implementation of the LPM method for continuous tracking is also developed. The usefulness of the proposed approach is demonstrated by its improved performance over other conventional tracking methods in a variety of simulation scenarios and for voltage flicker tracking in a simulated power distribution system.