Abstract
Language | English |
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Number of pages | 14 |
Journal | IEEE Transactions on Instrumentation and Measurement |
Early online date | 25 Apr 2018 |
DOIs | |
Publication status | E-pub ahead of print - 25 Apr 2018 |
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Keywords
- frequency measurement
- frequency estimation
- white noise
- Gaussian noise
- colored noise
- signal to noise ratio
- power system measurements
- finite impulse response filters
- Fourier transforms
- phasor measurement units
Cite this
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Dealing with front-end white noise on differentiated measurements such as frequency and ROCOF in power systems. / Roscoe, Andrew J.; Blair, Steven M.; Dickerson, William; Rietveld, Gert.
In: IEEE Transactions on Instrumentation and Measurement , 25.04.2018.Research output: Contribution to journal › Article
TY - JOUR
T1 - Dealing with front-end white noise on differentiated measurements such as frequency and ROCOF in power systems
AU - Roscoe, Andrew J.
AU - Blair, Steven M.
AU - Dickerson, William
AU - Rietveld, Gert
N1 - (c) 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.
PY - 2018/4/25
Y1 - 2018/4/25
N2 - This paper describes the way that white noise (including quantised input section sampling) imparts errors onto frequency and rate-of-change-of-frequency (ROCOF) measurements. The main paper focus concerns the use of filtered heterodyned (i.e. Fourier) analyses for single-phase and 3-phase systems, and the filtered Clarke transform for 3-phase systems. The rules and equations governing the effect of white noise on frequency and ROCOF are formulated for these techniques, explaining the subtle effects of aliasing, splitting signals and noise into their positive and negative frequency components, and the correlation or de-correlation of noise. It is shown that - as expected - for 3-phase AC measurements, averaging 3 single-phase Fourier measurements produces the same performance against noise as using a method based on Clarke’s transform, if identical filtering is used. Furthermore, by understanding the theory behind the frequency and ROCOF measurement processes, it is shown that to achieve the lowest RMS errors, in the presence of front-end white noise (alone, ignoring other dynamic signal and power quality aspects), a filter which provides ~40 dB/decade attenuation (i.e. a 2-boxcar cascade) is recommended for a frequency measurement, but a filter which rolls off at ~60 dB/decade (i.e. a 3-boxcar cascade) is recommended for a ROCOF measurement.
AB - This paper describes the way that white noise (including quantised input section sampling) imparts errors onto frequency and rate-of-change-of-frequency (ROCOF) measurements. The main paper focus concerns the use of filtered heterodyned (i.e. Fourier) analyses for single-phase and 3-phase systems, and the filtered Clarke transform for 3-phase systems. The rules and equations governing the effect of white noise on frequency and ROCOF are formulated for these techniques, explaining the subtle effects of aliasing, splitting signals and noise into their positive and negative frequency components, and the correlation or de-correlation of noise. It is shown that - as expected - for 3-phase AC measurements, averaging 3 single-phase Fourier measurements produces the same performance against noise as using a method based on Clarke’s transform, if identical filtering is used. Furthermore, by understanding the theory behind the frequency and ROCOF measurement processes, it is shown that to achieve the lowest RMS errors, in the presence of front-end white noise (alone, ignoring other dynamic signal and power quality aspects), a filter which provides ~40 dB/decade attenuation (i.e. a 2-boxcar cascade) is recommended for a frequency measurement, but a filter which rolls off at ~60 dB/decade (i.e. a 3-boxcar cascade) is recommended for a ROCOF measurement.
KW - frequency measurement
KW - frequency estimation
KW - white noise
KW - Gaussian noise
KW - colored noise
KW - signal to noise ratio
KW - power system measurements
KW - finite impulse response filters
KW - Fourier transforms
KW - phasor measurement units
UR - http://dx.doi.org/10.21227/H20926
UR - http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=19
U2 - 10.1109/TIM.2018.2822438
DO - 10.1109/TIM.2018.2822438
M3 - Article
JO - IEEE Transactions on Instrumentation and Measurement
T2 - IEEE Transactions on Instrumentation and Measurement
JF - IEEE Transactions on Instrumentation and Measurement
SN - 0018-9456
ER -