Accurate Dynamic Phasor Estimation by Matrix Pencil and Taylor Weighted Least Squares Method

Abstract

Out-of-band interference (OOBI) test is a bench-mark test for M-class phasor measurement units (PMUs) in IEEE/IEC 60255-118-1-2018 and C37.118.1a-2014. Because of the spectral interference produced by interharmonic, it is difficult for dynamic phasor estimators to satisfy the OOBI test requirements with a short observation time. To this end, this article proposed a Taylor weighted least squares (TWLS) method based on the matrix pencil for the dynamic phasor estimation of the OOBI contaminated signal. The proposed method first applies the matrix pencil algorithm to obtain rough estimations for the frequencies of the fundamental component and other components (i.e., harmonics, subharmonics, and interharmonics) within a few cycles. Then, the TWLS method was adopted to acquire more accurate estimations of the dynamic phasor and frequencies. The effectiveness of the proposed method is validated by simulations under steady and dynamic conditions that follow the requirements of the IEEE standard.