A proposed method for evaluating the frequency response of 22 kV outdoor current transformers for harmonic measurements in renewable energy plant applications

Murray, Ruan; Kock, J.A. de

doi:10.1109/amps.2019.8897784

Cited by 4 publications

(2 citation statements)

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“…In (1) indicates that the excitation current depends on the DC source, the RLC network time constants and the PRBS switching intervals which in turn are dependent on the PRBS clock frequency. In practice,…”

Section: Int J Powmentioning

confidence: 99%

“…In recent years, there has been a rapid increase in renewable energy sources such as photovoltaic and wind generators [1]- [3]. These energy sources have presented new challenges such as the risk of high harmonic voltage distortion due to their use of power electronic converters [1], [4], [5]. These power system harmonics have increased in both amplitude and frequency bandwidth.…”

Section: Introductionmentioning

confidence: 99%

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Characterizing power transformer frequency responses using bipolar pseudo-random current impulses

Sayyid

2021

IJPEDS

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The behaviour of a power transformer is complex and difficult to predict during transient conditions or during operation at frequencies below or above its nominal frequency, a phenomenon common in renewable energy plants due to harmonic distortion. Furthermore, the accuracy of a power system simulation depends on the models of critical subsystems such as the power transformers. This paper presents the use of a unique excitation waveform comprising of pseudo-random current impulses to accurately identify the wideband characteristics of a power transformer. By injecting the excitation waveform to the relevant transformer terminals, frequency responses are determined by cross-correlation of the perturbation signal, and the measured response. Compared to the traditional transformer identification methods, the pseudo-random current impulses offer a wideband excitation with a higher degree of controllability such that its spectral energy can be focused in the frequency band of interest. The proposed method was investigated on a 16 kVA, 22 kV/240 V single-phase transformer. The obtained wideband frequency responses provide useful information in harmonic penetration and over-voltage studies and are also used to estimate, with a high degree of accuracy, the lumped parameters of the equivalent transformer broadband circuit model.

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Section: Int J Powmentioning

confidence: 99%