A wideband zero-padded IpDFT framework with leakage-aware tone-set formation for harmonic and interharmonic synchrophasor estimation

Measurement, vol. 292, pp. 123262

Abstract

Phasor Measurement Units (PMUs) are increasingly deployed in distribution networks, where harmonics, interharmonics, and noise jeopardize synchrophasor accuracy, hence calling for wideband reporting. Wideband Multifrequency Synchrophasor Estimation (WMFSE) addresses this demand, but existing parametric approaches (e.g., Prony, ESPRIT, Matrix Pencil) remain computationally expensive and noise-sensitive. Nonparametric solutions, particularly Interpolated Discrete Fourier Transform (IpDFT) variants, offer a practical trade-off between accuracy and efficiency, making them suitable for real-time PMU operation. However, IpDFT-family estimators generally refine an already selected component or tone pair and do not address the formation of a physically consistent multifrequency tone set. This paper proposes a leakage-aware WMFSE framework that combines adaptive background thresholding, window-based sidelobe rejection, residual-background reclassification, adaptive Short-Range Leakage Limit determination, and selective zero-padding-adapted iterative IpDFT refinement. The resulting architecture separates tone-set formation from local leakage compensation, so only validated nearby components are passed to the iterative refinement stage. The method is assessed through a wideband validation framework complementary to IEC/IEEE 60255-118-1:2018 and based on concepts from IEC 61000-4-30 and IEC 61000-4-7, with comparisons against representative parametric, non-parametric and IpDFT-family methods. Results demonstrate robust harmonic and interharmonic estimation, improved weak-component exposure, and real-time feasibility while preserving FFT-level scalability.

Authors 8

1. César Cazal corresponding Aachen Institute for Automation of Complex Power Systems

   RWTH Aachen University

   Affiliation as printed

   Institute for Automation of Complex Power Systems, RWTH Aachen University, Aachen, Germany

2. Antonio Nardone

   Università degli studi di Cassino e del Lazio Meridionale

   Affiliation as printed

   Department of Electrical and Information Engineering “M. Scarano”, University of Cassino and Southern Lazio, Cassino, Italy

3. Guglielmo Frigo
   Affiliation as printed

   Department of Energy and Electrical Power, METAS, Bern, Switzerland

4. Luca Tari

   Università degli studi di Cassino e del Lazio Meridionale

   Affiliation as printed

   Department of Electrical and Information Engineering “M. Scarano”, University of Cassino and Southern Lazio, Cassino, Italy

5. Mirko Ginocchi

   European Commission · Joint Research Centre · Joint Research Centre

   Affiliation as printed

   European Commission, Joint Research Centre (JRC), Petten, The Netherlands

6. Ferdinanda Ponci Aachen Institute for Automation of Complex Power Systems

   RWTH Aachen University

   Affiliation as printed

   Institute for Automation of Complex Power Systems, RWTH Aachen University, Aachen, Germany

7. Arya Kumalajati Aachen Institute for Automation of Complex Power Systems

   RWTH Aachen University

   Affiliation as printed

   Institute for Automation of Complex Power Systems, RWTH Aachen University, Aachen, Germany

8. Antonello Monti Aachen Institute for Automation of Complex Power Systems

   Fraunhofer Institute for Applied Information Technology · RWTH Aachen University

   Affiliation as printed

   Fraunhofer-Institut für Angewandte Informationstechnik FIT, Aachen, Germany

   Institute for Automation of Complex Power Systems, RWTH Aachen University, Aachen, Germany