A Waveform Distortion Evaluation Method Based on a Simple Half-Cycle RMS Calculation

Cho, Soo-Hwan; Park, Chang-Hyun; Han, Ji Hyuk; Jang, Gilsoo

doi:10.1109/tpwrd.2012.2190304

Cited by 13 publications

(5 citation statements)

References 7 publications

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“…This section will further prove the presence of the second harmonic in the power system will cause fluctuation of rms, which may also indirectly cause voltage flicker. Basically, rms value can be calculated by the formula below [13]

rms = \sqrt{\frac{{false\sum}_{i = 1}^{N} {false(v false(i false) false)}^{2}}{N}}

where v ( i ) is represented as instantaneous voltage at sample i , N is represented as a window size (or samples). For this discussion, the value of N is 128, which is half cycle of 50 Hz power system.…”

Section: Fluctuation Of Rms Value With the Presence Of Second Harmonicmentioning

confidence: 99%

“…For the second harmonic, unambiguously, when a voltage supply contains the second harmonic, the root‐means‐square (rms) value of its waveform will be fluctuated due to its asymmetrical pattern [6, 13]. Meanwhile, the voltage flicker detection is carried out by analysing the rms value [13–15] and the formula for converting the rms value is included in flickermeter, as mentioned in IEC 61000‐4‐15 [9]. In the flickermeter, it has weighting filter which is designed to allow a signal passing within a range of frequency resulted from fluctuation of rms value.…”

Section: Introductionmentioning

confidence: 99%

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Investigation of severity of voltage flicker caused by second harmonic

Goh

Radzi

Hizam

et al. 2017

IET Science, Measurement & Technology

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Second harmonic produces asymmetrical waveform which leads to fluctuation of root-meanssquare (rms) value with certain frequency. Meanwhile, function of weighting filter in flickermeter is designed for sixth-order low-pass filtering function with frequency to be limited to 35 Hz, signal with frequency ranging from 35 to 100 Hz, at certain gain, still can pass through. Since the second harmonic produces fluctuation of rms value with 50 Hz, there is high possibility that it can be passed by this filter and thus resulting in flicker detection. Therefore, this study points out a worthwhile research gap to justify that the presence of the second harmonic can directly increase severity of voltage flicker. In addition, further simulation work using semi-converter has been carried out, as one of main even harmonic sources, in order to justify the concept. To practically validate the concept, Fluke power analyser 435 series II and programmable alternative current source are utilised in the experimental setup. In the main finding, it is confirmed that severity of the voltage flicker increases directly with the presence of the second harmonic and it also formed a clear relationship between short-term perceptibility (Pst) and percentage of the second harmonic component.

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rms = \sqrt{\frac{{false\sum}_{i = 1}^{N} {false(v false(i false) false)}^{2}}{N}}

Section: Fluctuation Of Rms Value With the Presence Of Second Harmonicmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Investigation of severity of voltage flicker caused by second harmonic

Goh

Radzi

Hizam

et al. 2017

IET Science, Measurement & Technology

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“…Light flicker is caused due to the low‐frequency fluctuations of the voltage magnitude and a 10 min raw data of the voltage signal is required to obtain the short‐term flicker severity [2], which is not always easy to achieve due to memory limitations. There are various approaches in the literature for the computation of light flicker [3–15]; however, to the knowledge of the authors there is no study which directly computes the light flicker in the absence of the voltage waveform, but presence of its RMS form instead, except for the work reported in [8]. In [8], however, four of the five blocks of the IEC flickermeter are used, but RMS computation is used to obtain the signal envelope instead of the first block of the IEC flickermeter [2].…”

Section: Introductionmentioning

confidence: 99%

Digital realisation of the IEC flickermeter using root mean square of the voltage waveform

Balouji

Salor

2016

IET Generation, Transmission & Distribution

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“…KOK hesabı için, IEEE Std.1159.2 [2] standardında yarım çevrim pencere uzunluğu tavsiye edilmiştir ve IEC 61000-4-30 da yarım çevrim KOK hesabını alternatif KOK hesaplama yöntemi olarak önermiştir [1]. Bunlara ek olarak literatürde KOK hesabı için çeşitli yöntemler denenmiştir [3][4][5][6][7][8][9][10][11][12][13][14][15]. [6]'da frekans değişimine göre KOK hesaplamasında yapılan frekansın geniş bir aralıkta değişimi için ve harmoniklerin varlığı durumunda diğer yayınlara göre çok daha ayrıntılı olarak incelenmiştir.…”

Section: Introductionunclassified

“…[6]'da frekans değişimine göre KOK hesaplamasında yapılan frekansın geniş bir aralıkta değişimi için ve harmoniklerin varlığı durumunda diğer yayınlara göre çok daha ayrıntılı olarak incelenmiştir. [7]'de yarım-çevrim KOK hesaplaması ile gerilim dalgasındaki bozulmaların değerlendirmesi yapılmıştır. [8][9]'da Güç Kalitesi (GK) olaylarının izlenmesi ve çözümlenmesi için KOK hesabı kullanılmıştır.…”

Section: Introductionunclassified

Assessment of RMS computation in terms of power quality event detection

Balouji

Salor

2015

2015 23nd Signal Processing and Communications Applications Conference (SIU)

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Özetçe-Bu bildiride, güç kalitesi olaylarının algılanması için IEC Standartlarında önerilmiş olan karekök-ortalamakare (KOK) hesaplamasını etkileyen faktörlerin incelenmesi için yapılan çalışmalar anlatılmıştır. IEC 61000-4-30Standardı'nda önerilen KOK hesabının, sinyal örneklerinin pencerenin başlangıcındaki sıfır geçişe göre kaymasına, güç sisteminin temel frekansının sapmasına ve temel bileşen ile harmonikler arasındaki faz farklarına göre doğruluğu, harmoniklerin varlığı ve yokluğu durumlarında incelenmiştir. Yapılan KOK hatalarının, örnekleme noktalarından çok az etkilenmesine rağmen, frekans sapmaları ve faz farkları durumunda tek harmonik bileşen durumunda dahi binde üçe varabileceği gösterilmiştir. IEC 61000-4-30 standardına önerilen KOK hesabının, güç kalitesi olaylarının doğru algılanması açısından sinyalin içeriğine göre değerlendirilebileceği önerilmiştir. Anahtar Kelimeler -Kök-Ortalama-Karekök (KOK), Güç Kalitesi, Güç Kalitesi Olayları, Güç Kalitesi Standartları.Abstract-In this paper, work on assessment of rootmean-square (RMS) computation recommended in the IEC Standards for power quality event detection with respect to various signal parameters. Correctness of the RMS computation in the standard IEC 61000-4-30, has been tested for power system frequency deviations, point-on-wave changes and phase differences between the fundamental frequency and harmonics in cases of both no harmonics and with harmonics. It has been shown that point-on-wave has negligible effect on RMS errors; however, frequency deviations and phase differences can significantly effect the RMS error, upto 0.3% even in the case of a single harmonic presence. It is recommended that the RMS computation method given in the IEC Standard 61000-4-30 should be assessed based on signal composition for the correctness of power quality event detection.

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A Waveform Distortion Evaluation Method Based on a Simple Half-Cycle RMS Calculation

Cited by 13 publications

References 7 publications

Investigation of severity of voltage flicker caused by second harmonic

Investigation of severity of voltage flicker caused by second harmonic

Digital realisation of the IEC flickermeter using root mean square of the voltage waveform

Assessment of RMS computation in terms of power quality event detection

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