A Fault Zone Identification Scheme for Busbar Using Correlation Coefficients Analysis
TL;DR: The proposed scheme is able to provide ultra-high-speed protection for the bus faults and solves the problem of CT saturation which is the biggest challenge in conventional low-impedance busbar differential protection schemes (87B).
Abstract: This paper proposes a new busbar protection scheme based on the analysis of correlation coefficients between the current waveforms of all lines connected to the busbar. The cross-correlation coefficients between current waveforms of each line in moving windows are calculated in a phase segregate manner with respect to a reference line. It's performance has been evaluated by modelling an existing 400-kV Indian substation in PSCAD/EMTDC software package. The proposed scheme is able to provide ultra-high-speed protection for the bus faults. It's stability has been tested against a wide range of external faults. It also solves the problem of CT saturation which is the biggest challenge in conventional low-impedance busbar differential protection schemes (87B).
Citations
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01 Aug 2018
TL;DR: The obtained results reveal the proposed 87BW function provides ultra-high-fast trip for internal and evolving external-to-internal faults, guaranteeing security for normal through-load and external faults as well, even in the case of early and severe current transformer saturation.
Abstract: This paper presents a new wavelet-based busbar differential protection algorithm, named as 87BW function. The instantaneous current-based differential protection fundamentals are taken into account and the well-known 1-out-of-1 and 2-out-of-2 tripping logics are mapped into the wavelet domain. Operating and restraint wavelet coefficients energy of currents are computed, regarding station configuration and bus zones boundaries. Thereby, the proposed 87BW function can be properly used in both static and dynamic busbar configuration. Its performance was evaluated through EMTP-based simulations of faults in a 230 kV power substation with double bus single breaker configuration. The obtained results reveal it provides ultra-high-fast trip for internal and evolving external-to-internal faults, guaranteeing security for normal through-load and external faults as well, even in the case of early and severe current transformer (CT) saturation.
12 citations
29 Feb 2020
TL;DR: Taking into account the preventive risks of the Mho relay and discover the new techniques of artificial intelligence, namely the neural network which can contribute to the precise and rapid detection of all types of short-circuit faults, the effectiveness of the methods proposed for the automatic diagnosis of faults is demonstrated.
Abstract: Received: 19 October 2019 Accepted: 13 December 2019 This study offers the opportunity to extend the functioning of the most advanced protection systems. The faults which can arise on the power transmission lines are numerous and varied: Short-circuit; Overvoltage; Overloads, etc. In the context of short circuits, the conventional sensor as the Mho distance relay also known as the admittance relay is generally used. This relay will be discussed later in this study. By taking into account the preventive risks of the Mho relay and discover the new techniques of artificial intelligence, namely the neural network which can contribute to the precise and rapid detection of all types of short-circuit faults. The results of the simulation tests demonstrate the effectiveness of the methods proposed for the automatic diagnosis of faults.
5 citations
Cites methods from "A Fault Zone Identification Scheme ..."
...Some methods used in this area include: Support Vector Machine (SVM) for fault diagnosis [1-3]....
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09 Jul 2021
Cites background from "A Fault Zone Identification Scheme ..."
...As can be observed from (9), if we try to minimize the norm of the output weights ‖‖‖β‖‖‖, it would be equal to the maximization of the marginal distance of two different classes (2∕‖‖‖β‖‖‖) in the ELM feature space....
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...Based on Equation (1), if the differential current IDIF is higher than the F I G U R E 1 Percentage differential protection configuration22 F I G U R E 2 Differential protection scheme maloperation under CT saturation applied to the strategy proposed by Siemens....
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...26 Equation (9) provides the objective function of the ELM model26: Minimize ∶ ||Hβ − T||2 and ||β|| (9)...
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...Equation (8) defines the decision function for the problem of binary classification26: f (x) = sign(h(x)𝛽) (8) It is worth noting that our investigated problem, that is, discriminating between internal fault and other conditions (external fault or inrush current), is a binary classification problem....
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...This way of defining objective function improves its generalization performance, based on Bartlett’s theory.26 Equation (9) provides the objective function of the ELM model26: Minimize ∶ ||H𝛽 − T||2 and ||𝛽|| (9) where the output matrix of the hidden layer is denoted as H: H = ⎡⎢⎢⎢⎣ h(x1) ⋮ h(xN) ⎤⎥⎥⎥⎦ = ⎡⎢⎢⎢⎣ h1(x1) … hL(x1) ⋮ ⋮ ⋮ h1(xN) ⋮ hL(xN) ⎤⎥⎥⎥⎦ (10) As can be observed from (9), if we try to minimize the norm of the output weights ‖‖‖𝛽‖‖‖, it would be equal to the maximization of the marginal distance of two different classes (2∕‖‖‖β‖‖‖) in the ELM feature space.26...
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References
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TL;DR: A method of symmetrical component analysis for the detection of current-transformer saturation in a numerical current differential feeder protection relay shows significant improvement in sensitivity on internal faults while still maintaining a high level of stability on external faults and nonfault events.
Abstract: A method of symmetrical component analysis for the detection of current-transformer (CT) saturation in a numerical current differential feeder protection relay is presented in this paper. The performance of the differential relay is investigated for various faults on a typical Electro-Magnetic Transients Program/Alternative Transients Program (EMTP/ATP) simulated transmission feeder. The simulator includes the effects of CT saturation. A comparison between simulation and tests conducted on an analog model testbench are also evaluated. The results show a high degree of similarity and illustrate the effect that CT saturation imposes on the sensitivity and stability of the protection scheme. An algorithm is presented that shows significant improvement in sensitivity on internal faults while still maintaining a high level of stability on external faults and nonfault events.
87 citations
14 Nov 2005
TL;DR: In this article, a wavelet-packet transform (WPT) based differential busbar-protection technique is presented, which decomposes the fault signal into different frequency bands in the time domain.
Abstract: A novel wavelet-packet-transform- (WPT-) based differential busbar-protection technique is presented. The paper uses the wavelet-packet- transform (WPT) method to extract features from a fault-current signal. The WPT can decompose the fault signal into different frequency bands in the time domain. The differential signal is computed from the decomposed extracted signal. The WPT-based differential busbar-protection scheme solves several problems of current protective relays. The CT error and ratio-mismatch problems do not have any impact on the proposed WPT-based scheme. ATP simulations are used to test and validate the proposed technique for model-power-system faults.
56 citations
TL;DR: The implementation and testing of a superimposed directional comparison technique for bus protection based on an IEC61850 process bus is investigated and design, hardware implementation, and related issues of DCBPU are described.
Abstract: A directional comparison bus protection unit (DCBPU) can provide a high speed bus fault clearing in the IEC61850 process-bus environment. This technique is based on superimposed fault direction for each circuit connected to the protected bus. In this paper, the implementation and testing of a superimposed directional comparison technique for bus protection based on an IEC61850 process bus is investigated. Design, hardware implementation, and related issues of DCBPU are described. A unique test setup is proposed and developed for testing DCBPU, including merging unit simulator, traffic generator, prototype DCBPU, and Ethernet switches to simulate the real IEC 61850-based substation automation process bus. Test results are reported.
42 citations
TL;DR: In this paper, an extra high-speed busbar protection technique according to the propagation theory of traveling wave is proposed, where the detected initial traveling waves on all connected lines will come from their back, which are defined as positive direction traveling waves.
Abstract: This paper proposes an extra high-speed busbar protection technique according to the propagation theory of traveling wave. When the fault occurs on the busbar, the detected initial traveling waves on all connected lines will come from their back, which are defined as positive direction traveling waves. While a fault occurs on any one of these lines, the detected initial traveling waves on all healthy lines are positive direction traveling waves; however, the traveling wave direction on the faulted line is negative. Within a short duration of postfault, a criterion discriminating fault direction can be established according to the amplitude integral relationships between the positive direction traveling wave and the negative direction traveling wave. Analyzing the detected traveling wave directions for all lines, a distributed busbar protection scheme can be constructed. To evaluate the proposed technique, a typical busbar model was built. Simulation results show that the proposed method can rapidly and reliably discriminate the internal faults from external faults, and the protection performances are immune to fault resistances, fault inception angles, fault types, and current-transformer saturation.
42 citations
"A Fault Zone Identification Scheme ..." refers background in this paper
...Travelling wave-based scheme presented in [17] provides real time ultra-high-speed protection....
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TL;DR: In this article, a wavelet transform-based directional algorithm for busbar protection is proposed, which decomposes the current and voltage signals into their first-level details, which consist of frequencies in 500- to 1000-Hz bandwidth, for generating directional signals.
Abstract: This paper proposes a novel wavelet-transform-based directional algorithm for busbar protection. The algorithm decomposes the current and voltage signals into their first-level details, which consist of frequencies in 500- to 1000-Hz bandwidth, for generating directional signals. A high level of computational efficiency is achieved compared to the other wavelet-transform-based algorithms proposed, since only the high-frequency details at the first level are employed in this algorithm. The validity of this method was exhaustively tested by simulating various types of faults on a substation modeled in the alternative transients program/electromagnetic transients program. The algorithm correctly discriminated between bus faults, various types of external faults, and transformer energization even in the presence of current-transformer saturation. This paper also provides the design details of the algorithm using field-programmable gate array technology.
39 citations
"A Fault Zone Identification Scheme ..." refers background in this paper
...Wavelet Transform-based schemes [18]–[22] have been presented by researchers which extract information about the fault characteristics from the transient components....
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