Journal ArticleDOI
Impedance measurement for improved power quality-Part 1: the measurement technique
TLDR
In this article, an improved power system impedance measurement technique is introduced, which injects a short duration current spike into the supply, and derives the impedance from the measured current and voltage.Abstract:
This paper introduces an improved power system impedance measurement technique. The technique injects a short duration current spike into the supply, and derives the impedance from the measured current and voltage. The method is shown to work extremely well under most conditions, by experimental evaluation using a 45-kVA laboratory prototype. Degradation is observed when a voltage-source-type power-electronic load is connected directly to the measurement equipment. An alternative signal processing strategy, based upon the Prony method is proposed to improve the estimation under these conditions. This method also reduces the overall transient data capture time, thus allowing a faster, online calculation of the impedance.read more
Citations
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Journal ArticleDOI
Self-commissioning notch filter for active damping in three phase LCL-filter based grid converters
TL;DR: In this paper, the authors proposed a simple tuning procedure for the LCL-filter that results in proper robustness in order to cope with the grid inductance variations by means of Fourier analysis.
Journal ArticleDOI
Grid Impedance Estimation via Excitation of $LCL$ -Filter Resonance
TL;DR: In this paper, the authors proposed to use a controlled excitation in measuring the grid impedance, since this one influences also the resonance frequency, and validated both by simulations and experimental results.
Journal ArticleDOI
Minimal Invasive Equivalent Grid Impedance Estimation in Inductive–Resistive Power Networks Using Extended Kalman Filter
Nils Hoffmann,Friedrich W. Fuchs +1 more
TL;DR: In this paper, an extended Kalman filter is proposed to utilize the noise that is already present at the connection point of the power converter to overcome the need of active disturbance injection to estimate the equivalent grid impedance.
Journal ArticleDOI
Grid Impedance Monitoring System for Distributed Power Generation Electronic Interfaces
TL;DR: A grid impedance monitoring system for distributed power generation electronic interfaces that estimates the grid equivalent impedance and voltage source from the voltage measurements performed at the point of common coupling using a recursive least-squares algorithm implemented in the complex field.
Journal ArticleDOI
Utility Harmonic Impedance Measurement Based on Data Selection
TL;DR: In this paper, a new measurement technique based on the complex data-based least-square regression, combined with two techniques of data selection, is proposed to determine the utility harmonic impedances.
References
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Numerical Methods for Unconstrained Optimization and Nonlinear Equations (Classics in Applied Mathematics, 16)
TL;DR: In this paper, Schnabel proposed a modular system of algorithms for unconstrained minimization and nonlinear equations, based on Newton's method for solving one equation in one unknown convergence of sequences of real numbers.
Book
Numerical methods for unconstrained optimization and nonlinear equations
TL;DR: Newton's Method for Nonlinear Equations and Unconstrained Minimization and methods for solving nonlinear least-squares problems with Special Structure.
Journal ArticleDOI
Spectrum analysis—A modern perspective
Steven Kay,S.L. Marple +1 more
TL;DR: In this paper, a summary of many of the new techniques developed in the last two decades for spectrum analysis of discrete time series is presented, including classical periodogram, classical Blackman-Tukey, autoregressive (maximum entropy), moving average, autotegressive-moving average, maximum likelihood, Prony, and Pisarenko methods.
Journal ArticleDOI
Application issues of active power filters
TL;DR: In this article, the authors have characterized common nonlinear loads have been characterized into two types of harmonic sources, current-source type of harmonic source and voltage source type of source, and discussed the compensation characteristics of both parallel active filters and series active filters.