A SVD-based Dynamic Harmonic Phasor Estimator with Improved Suppression of Out-of-Band Interference

TL;DR

This paper presents a novel SVD-based harmonic phasor estimator that effectively suppresses out-of-band interference, improving accuracy in power systems with nonlinear loads and power electronic devices.

Contribution

It introduces an SVD-enhanced Taylor-Fourier transform algorithm with adjustable parameters to minimize out-of-band interference effects in dynamic harmonic phasor estimation.

Findings

Achieves accurate harmonic phasor estimation under multiple interferences.

Demonstrates robustness against noise, frequency deviation, and dynamic conditions.

Outperforms conventional methods in suppressing out-of-band interference.

Abstract

The diffusion of nonlinear loads and power electronic devices in power systems deteriorates the signal environment and increases the difficulty of measuring harmonic phasors. Considering accurate harmonic phasor information is necessary to deal with harmonic-related issues, this paper focuses on realizing accurate dynamic harmonic phasor estimation when the signal is contaminated by certain interharmonic tones, i.e. the out-of-band interference (OBI). Specifically, this work introduces the singular value decomposition into the Taylor-Fourier transform algorithm, deriving a general decomposition form for harmonic phasor filters, and yielding a set of adjustable parameters. Then these parameters are configured to minimize the negative influence of OBI on the dynamic harmonic phasor filters. Based on the recommended parameter values, the optimized harmonic estimator is obtained, and then tested under signals distorted by OBI, harmonic, noise, and in worse cases, frequency deviation, and some dynamic conditions. Test results show the proposal achieves good harmonic phasor estimation even under multiple interferences and dynamic scenarios, and has a much weaker dependence on OBI tones compared to conventional approaches.