Abstract
The Interpolated Discrete Fourier Transform (IpDFT) is one of the most popular algorithms for Phasor Measurement Units (PMUs), due to its quite low computational complexity and its good accuracy in various operating conditions. However, the basic IpDFT algorithm can be used also as a preliminary estimator of the amplitude, phase, frequency and rate of change of frequency of voltage or current AC waveforms at times synchronized to the Universal Coordinated Time (UTC). Indeed, another cascaded algorithm can be used to refine the waveform parameters estimation. In this context, the main novelty of this work is a fair and extensive performance comparison of three different state-of-the-art IpDFT-tuned estimation algorithms for PMUs. The three algorithms are: (i) the so-called corrected IpDFT (IpDFTc), which is conceived to compensate for the effect of both the image of the fundamental tone and second-order harmonic; (ii) a frequency-tuned version of the Taylor Weighted Least-Squares (TWLS) algorithm, and (iii) the frequency Down-Conversion and low-pass Filtering (DCF) technique described also in the IEEE/IEC Standard 60255-118-1:2018. The simulation results obtained in the P Class and M Class testing conditions specified in the same Standard show that the IpDFTc algorithm is generally preferable under the effect of steady-state disturbances. On the contrary, the tuned TWLS estimator is usually the best solution when dynamic changes of amplitude, phase or frequency occur. In transient conditions (i.e., under the effect of amplitude or phase steps), the IpDFTc and the tuned TWLS algorithms do not clearly outperform one another. The DCF approach generally returns the worst results. However, its actual performances heavily depend on the adopted low-pass filter.
Highlights
The Phasor Measurement Units (PMUs) are instruments designed to measure amplitude, phase, frequency, and Rate Of Change Of Frequency (ROCOF) of voltage and currentAC signals in crucial locations of transmission and distribution systems [1]
The performances of the Interpolated Discrete Fourier Transform (IpDFT)-tuned algorithms presented in Section 2 are compared under multiple testing conditions
The results of the IpDFT-tuned estimation algorithms under study are compared over 1000 data records in the P Class and M Class steady-state and dynamic testing conditions specified in [10]
Summary
The Phasor Measurement Units (PMUs) are instruments designed to measure amplitude, phase, frequency, and Rate Of Change Of Frequency (ROCOF) of voltage and currentAC signals in crucial locations of transmission and distribution systems [1]. Coordinated Time (UTC); the capability to stream real-time data to the so-called Phasor Data Concentrators (PDCs) with reporting rates ranging between about 10 frame/s and 100 frame/s; high measurement accuracy, as specified in the IEEE/IEC Standard 60255-118-1:2018, in the following referred to as the “Standard” for the sake of brevity [10]; fast responsiveness (in the order of a few power line cycles) in order to trigger adequate protection schemes when severe phasor magnitude or phase changes occur due to faults or grid topology changes [11]. The former ones can be less accurate than the latter, but they must be considerably faster.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
