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Vladimir Terzija - One of the best experts on this subject based on the ideXlab platform.

  • measurement based transmission Line Parameter estimation with adaptive data selection scheme
    2018
    Co-Authors: Yaping Zhang, Hengxu Zhang, Vladimir Terzija
    Abstract:

    Accurate Parameters of transmission Lines are critical for power system operation and control decision making. Transmission Line Parameter estimation based on measured data is an effective way to enhance the validity of the Parameters. This paper proposes a multi-point transmission Line Parameter estimation model with an adaptive data selection scheme based on measured data. Data selection scheme, defined with time window and number of data points, is introduced in the estimation model as additional variables to optimize. The data selection scheme is adaptively adjusted to minimize the relative standard deviation (RSD) of estimated Parameters. An iterative technique derived from the Newton method is adopted to solve the proposed model by fitting the relationship between the RSD and data selection scheme with exponential functions. Simulated data are applied to illustrate the performance of the proposed model. Some 500-kV transmission Lines from a provincial power system of China are estimated to demonstrate the applicability of the presented model. The superiority of the proposed model over fixed data selection schemes is also verified.

  • methodology for testing a Parameter free fault locator for transmission Lines
    2016
    Co-Authors: M Popov, Z M Radojevic, G Preston, Shreya Parmar, Gert Rietveld, Vladimir Terzija
    Abstract:

    This paper presents a comparison between two different approaches to fault location both with and without utilising transmission Line Parameters. Firstly, an impedance-based Parameter-dependent algorithm, derived by using modal transformation theory and fast Fourier transform is presented. The methodology is able to locate the fault whether it is on an overhead Line or on an underground power cable. The second algorithm is a Parameter-free fault location method that uses time synchronised data. Here, the unknown fault location is determined from voltage and current phasors, synchronously measured at both Line terminals. This approach to fault location avoids the requirement for prior knowledge of Line Parameters, which is advantageous as Line Parameters are not always known precisely. This paper presents the results of algorithm testing through the use of ATPDraw simulations and MATLAB. The results were validated through laboratory experiments. The results of the Line Parameter-free model are compared with those from the Parameter-dependent model. Both algorithms were tested for single Line to ground faults.

  • new Parameter free fault location algorithm for transmission Lines in phasor domain
    2012
    Co-Authors: Shantanu Padmanabhan, Vladimir Terzija
    Abstract:

    This paper presents a new fault location algorithm for transmission Lines. It is different from other fault location algorithms since it does not require the use of any Line Parameters. Line Parameter settings are only approximate and may vary with weather and loading condition. The settings-free aspect of the new algorithm makes it more reliable and accurate. All calculations are carried out in the phasor domain unlike many of the settings-free algorithms. The phasor domain approach in fault location offers an important advantage over the sequence domain approach as modifications can be made easily for Lines where the sequence networks are coupled e.g. a series compensated Line during fault. The algorithm uses synchronized data samples for voltage and currents from both ends of the Line.

  • new settings free fault location algorithm based on synchronised sampling
    2011
    Co-Authors: G Preston, Chulhwan Kim, Z M Radojevic, Vladimir Terzija
    Abstract:

    This study presents a new numerical algorithm for fault location on transmission Lines. It does not require Line Parameters, it is settings-free, which is a radical step forward compared to the existing approaches that require this information. Line Parameters are only approximately constant, they differ as the loading and weather conditions vary; this affects the accuracy of the existing fault location algorithms. Thus, an approach that does not require Line Parameters would be more robust, accurate, flexible and cost-effective than those approaches that do require Line Parameter information to determine the location of the fault. This is essential for the fast and secure elimination of faults on transmission Lines; consequently, the solution leads to a significant improvement in the quality of the energy supply. The new algorithm is based on the emerging synchronised measurement technology, using synchronised data sampling at both Line terminals. The study presents the algorithm derivation and the results of thorough testing using the ATP-EMTP simulations.

  • new approach for fault location on transmission Lines not requiring Line Parameters
    2009
    Co-Authors: Z M Radojevic, Chulhwan Kim, M Popov, G Preston, Vladimir Terzija
    Abstract:

    This paper presents a new numerical algorithm for fault location on transmission Lines. It does not require Line Parameters, which is a radical step forward compared to the existing approaches, which require this information, so the algorithm can be considered as a settings-free algorithm. Line Parameters are only approximately constant; they differ with the loading and weather conditions. Thus, an approach which does not require them would be more robust, accurate and flexible, than those approaches that do require Line Parameter information to determine the location to the fault. This is essential for the fast and secure elimination of faults on transmission Lines, and, consequently, the solution leading to a significant improvement of the quality of the energy supply. The new algorithm uses synchronised data sampling at both Line terminals, which is a prerequisite for the successful algorithm application. The paper presents the results of the initial algorithm testing through the use of ATP-EMTP simulations.

Yun Zhihao - One of the best experts on this subject based on the ideXlab platform.

  • a fault location algorithm for high voltage overhead power transmission Line based on Line Parameter estimation
    2004
    Co-Authors: Yun Zhihao
    Abstract:

    In existing fault location algorithms the Parameters of power transmission Line are regarded as known constants, so the accuracy of fault location depends on that of the value of Parameters. Here, a least-squares algorithm for fault location based on Parameter estimation of transmission Line is proposed in which the accurate value of the Line Parameters is not to be known and no hardware should be added. Using the data provided by the fault recorders equipped at the both ends of the transmission Line, the on-Line Parameter estimation of the transmission Line can be carried out and the position where fault occurs can be determined, therefore the influence of inaccuracy or variation of the Line Parameter value, which is caused by the practical factors on site, on the accuracy of fault location can be overcome. The results from theoretical analysis and simulation show that high accuracy of fault location can be obtained by use of the proposed algorithm.

Hongyu You - One of the best experts on this subject based on the ideXlab platform.

  • Linear approximations for the influence of phasor angle difference errors on Line Parameter calculation
    2020
    Co-Authors: Ancheng Xue, Kenneth E Martin, Hongyu You
    Abstract:

    Phase angle measurements from phasor measurement units (PMUs) may have errors that can significantly affect Line Parameter calculation. In this paper, approximate expressions for the influence of phase angle difference errors on Line Parameter calculation are derived. Specifically, first the PMU phase angle error at both ends of a Line is analyzed and an equivalent synchronization error is defined. Second, approximated expressions for the influence of current & voltage phase angle difference error on the Line Parameters are derived. The voltage amplitude ratio on the relative error of Line reactance, resistance and capacitance measurement through the $\pi -$type equivalent model are considered. The influence of voltage and current phase angle difference error on reactance and resistance is shown from the perspective of relative sensitivity. The relative sensitivity expressions in active power form are given and the identifiable conditions of Line reactance Parameters based on PMU data are given. In addition, this paper presents the influence mechanism of voltage magnitude and discusses the case of synchronization issue. Finally, the accuracy of the sensitivity equations are verified by simulations, and the influence of the voltage amplitude ratio and the Line flow on the identification result is quantitatively analyzed.

  • Linear approximations for the influence of phasor angle difference errors on Line Parameter calculation
    2019
    Co-Authors: Ancheng Xue, Kenneth E Martin, Hongyu You
    Abstract:

    Phase angle measurements from phasor measurement units (PMUs) may have errors that can significantly affect Line Parameter calculation. In this paper, approximate expressions for the influence of phase angle difference errors on Line Parameter calculation are derived. Specifically, first the PMU phase angle error at both ends of a Line is analyzed and an equivalent synchronization error is defined; second, approximated expressions for the influence of current and voltage phase angle difference error on the Line Parameters are derived. The voltage amplitude ratio on the relative error of Line reactance, resistance, and capacitance measurement through the π -type equivalent model are considered. The influence of voltage and current phase angle difference error on reactance and resistance is shown from the perspective of relative sensitivity. The relative sensitivity expressions in active power form are given and the identifiable conditions of Line reactance Parameters based on PMU data are given. In addition, this paper presents the influence mechanism of voltage magnitude and discusses the case of synchronization issue. Finally, the accuracy of the sensitivity equations is verified by simulations, and the influence of the voltage amplitude ratio and the Line flow on the identification result is quantitatively analyzed.

S A Soman - One of the best experts on this subject based on the ideXlab platform.

  • estimation of zero sequence Parameters of mutually coupled transmission Lines from synchrophasor measurements
    2017
    Co-Authors: Kalyan Dasgupta, S A Soman
    Abstract:

    The authors consider the problem of estimating zero sequence Parameters of a transmission Line using synchrophasor data. When a set of three-phase transmission Lines share, partial or complete, right of way, then their zero sequence models exhibit mutual coupling. As such the zero sequence Parameters cannot be estimated by Linear least squares or total least squares (TLS) technique which are the preferred methods when dealing with the positive sequence Line Parameter estimation problem. Further, method design has to factor the constraint of a sparse data set when dealing with zero sequence phasors. Therefore, the authors propose orthogonal distance regression approach for solving the zero sequence Parameter estimation problem. This generalises the method of TLS to the non-Linear Parameter estimation problem considering noise in both the voltage and current synchrophasor measurements. Extensive case studies and comparative evaluations are presented to demonstrate the efficacy of the proposed approach.

  • detection and correction of systematic errors in instrument transformers along with Line Parameter estimation using pmu data
    2017
    Co-Authors: Kedar Khandeparkar, S A Soman, Gopal Gajjar
    Abstract:

    We consider the following two estimation problems from synchrophasor measurements: first, estimation of positive sequence transmission Line Parameters and second, estimation of ratio correction factors for instrument transformers (ITs), also known as remote meter calibration (RMC). These two seemingly distinct problems are actually interrelated because incorrect Parameters of any one set adversely affects the results of another. Hence, a simultaneous Line Parameter and RMC approach is proposed. Following extensions and adaptions viz., implicit RMC, explicit RMC, solving an individual Line problem, and solving a network level problem are proposed. Open-circuit tests on transmission Lines are proposed to improve accuracy in RMC. A decibel-scale-based statistical score is introduced for detection of ITs which require calibration. Extensive simulation results are presented to justify the claims.

  • Line Parameter estimation using phasor measurements by the total least squares approach
    2013
    Co-Authors: Kalyan Dasgupta, S A Soman
    Abstract:

    Transmission Line Parameters can be estimated from PMU data at the end of two Lines. Both Linear least squares and total least squares approaches have been suggested in the literature. This paper further develops the TLS approach for estimating positive sequence Line Parameters. We present an algorithm for appropriate selection of phasor samples (similar to down sampling) so as to contain independent information for better filtering action. Results of Parameter estimation will be erroneous if the CVT accuracy is compromised. We propose a Durbin Watson test to detect serial correlation in errors to flag biased CVT measurements. Finally, we compare and contrast TLS and LS estimators and demonstrate superiority of TLS approach using ATP-EMTP simulations.

Ancheng Xue - One of the best experts on this subject based on the ideXlab platform.

  • Linear approximations for the influence of phasor angle difference errors on Line Parameter calculation
    2020
    Co-Authors: Ancheng Xue, Kenneth E Martin, Hongyu You
    Abstract:

    Phase angle measurements from phasor measurement units (PMUs) may have errors that can significantly affect Line Parameter calculation. In this paper, approximate expressions for the influence of phase angle difference errors on Line Parameter calculation are derived. Specifically, first the PMU phase angle error at both ends of a Line is analyzed and an equivalent synchronization error is defined. Second, approximated expressions for the influence of current & voltage phase angle difference error on the Line Parameters are derived. The voltage amplitude ratio on the relative error of Line reactance, resistance and capacitance measurement through the $\pi -$type equivalent model are considered. The influence of voltage and current phase angle difference error on reactance and resistance is shown from the perspective of relative sensitivity. The relative sensitivity expressions in active power form are given and the identifiable conditions of Line reactance Parameters based on PMU data are given. In addition, this paper presents the influence mechanism of voltage magnitude and discusses the case of synchronization issue. Finally, the accuracy of the sensitivity equations are verified by simulations, and the influence of the voltage amplitude ratio and the Line flow on the identification result is quantitatively analyzed.

  • Linear approximations for the influence of phasor angle difference errors on Line Parameter calculation
    2019
    Co-Authors: Ancheng Xue, Kenneth E Martin, Hongyu You
    Abstract:

    Phase angle measurements from phasor measurement units (PMUs) may have errors that can significantly affect Line Parameter calculation. In this paper, approximate expressions for the influence of phase angle difference errors on Line Parameter calculation are derived. Specifically, first the PMU phase angle error at both ends of a Line is analyzed and an equivalent synchronization error is defined; second, approximated expressions for the influence of current and voltage phase angle difference error on the Line Parameters are derived. The voltage amplitude ratio on the relative error of Line reactance, resistance, and capacitance measurement through the π -type equivalent model are considered. The influence of voltage and current phase angle difference error on reactance and resistance is shown from the perspective of relative sensitivity. The relative sensitivity expressions in active power form are given and the identifiable conditions of Line reactance Parameters based on PMU data are given. In addition, this paper presents the influence mechanism of voltage magnitude and discusses the case of synchronization issue. Finally, the accuracy of the sensitivity equations is verified by simulations, and the influence of the voltage amplitude ratio and the Line flow on the identification result is quantitatively analyzed.