PMU Phasor Estimation Using Different Techniques

2021 ◽  
pp. 70-99
Author(s):  
Hamid Bentarzi ◽  
Abderrahmane Ouadi
Keyword(s):  
Fourier Transform ◽  
Discrete Fourier Transform ◽  
Dynamic Models ◽  
Zero Crossings ◽  
Phasor Measurement ◽  
Input Signals ◽  
Measurement Units ◽  
Phasor Estimation ◽  
Phase Angles ◽  
True Values

Many models of phasor measurement units (PMU) have been implemented; however, few dynamic models have been developed when the power system parameters change. It is necessary to use a method that can somehow estimate the frequency and correct the phasors. The conventional way to determine frequency is to detect zero crossings per unit time. However, this method has many drawbacks such as high cost and low accuracy. Also, after the frequency determination, the phasor should be corrected by suitably modifying the algorithm without omitting any data. This chapter presents different estimation techniques such as discrete Fourier transform (DFT), smart discrete Fourier transform (SDFT) that may be used to estimate the phasors. These estimated values would be incorrect if the input signals are at an off-nominal frequency and the phase angles would drift away from the true values. To correct this issue, first of all, the off-nominal frequency has been estimated using different techniques such as least error squares and phasor measurement angle changing, and then it is used to correct the phasors.

Use of Synchronized Phasor Measurements for Model Validation in ERCOT

2013 ◽  
Vol 14 (1) ◽  
pp. 87-94
Author(s):  
Sarma Nuthalapati ◽  
Jian Chen ◽  
Prakash Shrestha ◽  
Shun-Hsien Huang ◽  
John Adams ◽  
...  
Keyword(s):  
Dynamic Models ◽  
Measurement Technology ◽  
Small Signal Stability ◽  
Record System ◽  
Signal Stability ◽  
Phasor Measurement ◽  
Phasor Measurements ◽  
Measurement Units ◽  
Phase Angles ◽  
Synchronized Phasor Measurement

Abstract This paper discusses experiences in the use of synchronized phasor measurement technology in Electric Reliability Council of Texas (ERCOT) interconnection, USA. Implementation of synchronized phasor measurement technology in the region is a collaborative effort involving ERCOT, ONCOR, AEP, SHARYLAND, EPG, CCET, and UT-Arlington. As several phasor measurement units (PMU) have been installed in ERCOT grid in recent years, phasor data with the resolution of 30 samples per second is being used to monitor power system status and record system events. Post-event analyses using recorded phasor data have successfully verified ERCOT dynamic stability simulation studies. Real time monitoring software “RTDMS”® enables ERCOT to analyze small signal stability conditions by monitoring the phase angles and oscillations. The recorded phasor data enables ERCOT to validate the existing dynamic models of conventional and/or wind generator.

Harmonic and Interharmonic Phasor Estimation Using Matrix Pencil Method for Phasor Measurement Units

2021 ◽  
Vol 21 (2) ◽  
pp. 945-954
Author(s):  
Lakshan Bernard ◽  
Sunny Goondram ◽  
Behrooz Bahrani ◽  
Athanasios A. Pantelous ◽  
Reza Razzaghi
Keyword(s):  
Matrix Pencil ◽  
Phasor Measurement Units ◽  
Phasor Measurement ◽  
Matrix Pencil Method ◽  
Measurement Units ◽  
Phasor Estimation

scholarly journals Orthogonal Components Forming of the Microprocessor-Based Protection Input Signals

2020 ◽  
Vol 63 (4) ◽  
pp. 328-339 ◽  
Author(s):  
F. A. Romaniuk ◽  
V. Yu. Rumiantsev ◽  
Yu. V. Rumiantsev ◽  
V. S. Kachenya
Keyword(s):  
Fourier Transform ◽  
Discrete Fourier Transform ◽  
High Speed ◽  
Block Diagram ◽  
Short Circuit ◽  
Current Transformer ◽  
Secondary Current ◽  
Measuring Devices ◽  
Input Signals ◽  
Orthogonal Components

The use of orthogonal components (OS) is the main direction of determining information parameters in microprocessor relay protection and automation of electric power systems. Most of the measuring devices used in modern protection and automation devices can be implemented using known operating systems. Digital non-recursive frequency filters based on discrete Fourier transform are used for OS selection. The main disadvantage of these filters is their low performance that exceeds the period of industrial frequency. For the construction of high-speed measuring devices, this time of establishing the true output signal is often unacceptable. The article proposes to form the equivalent signal OS in microprocessor defenses based on the values of the cosine and sine axes of the main harmonic formed using a discrete Fourier transform, by multiplying them by a correction factor, which is a function of the values of the input signal amplitude and its main harmonic. The proposed algorithm for generating OS input signals in microprocessor defenses is characterized by high performance in transient modes and has wide functionality. A block diagram of an OS equivalent signal generator has been developed, all blocks of which can be implemented according to known schemes on a microelectronic and microprocessor element base. The OS shaper model is implemented in the MatLab-Simulink dynamic modeling environment. The model functioning was checked using two types of test actions, viz. a sinusoidal signal with a frequency of 50 Hz (idealized action) and a signal close to the real secondary current of a short-circuit current transformer. As a result of the performed calculations, a significant (up to two times) in the speed of the proposed method of OS formation in comparison with the formers based on the discrete Fourier transform, frequency properties of both formers being identical.

scholarly journals Research on Discrete Fourier Transform-Based Phasor Measurement Algorithm for Distribution Network under High Frequency Sampling

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2203 ◽  
Author(s):  
Zhiguo Zhou ◽  
Ruliang Lin ◽  
Lifeng Wang ◽  
Yi Wang ◽  
Hansen Li
Keyword(s):  
Fourier Transform ◽  
Discrete Fourier Transform ◽  
High Frequency ◽  
Distribution Network ◽  
Sampling Rate ◽  
Waveform Data ◽  
Phasor Measurement ◽  
Frequency Sampling ◽  
Measurement Algorithm ◽  
High Frequency Sampling

This paper proposes a phasor measurement algorithm that is suitable for a distribution network. Under the condition of fixed interval and high frequency sampling, the algorithm uses a dynamic calibration factor to correct the traditional Discrete Fourier Transform (DFT) algorithm, which solves the shortcomings of the rapid decline in traditional algorithm measurement accuracy under the condition of power system frequency deviation or dynamic measurement. Under the high sampling rate of the international distribution network waveform data, the conventional phasor is used to represent the theoretical phasor, and the value of the conventional phasor is compensated to make the result closer to the theoretical value. Finally, the phasor measurement software simulation platform is built in Matlab/Simulink, based on the principle of the algorithm, providing a simulation environment for researchers to verify the phasor measurement algorithm of the distribution network and the fault location, state estimation, or other advanced applications.

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