Auto-reclosing Scheme Research Articles

An efficient deep learning based scheme for adaptive auto-reclosing in power transmission lines

As a large percentage of faults in transmission lines are single-line-to-ground (SLG) and transient in nature, the use of adaptive single-phase auto-reclosing (ASPAR) schemes is essential. In this paper, a new scheme for ASPAR is proposed to improve the stability and reliability of power transmission lines. The proposed approach distinguishes between the transient and permanent faults by using the feature of Stationary Wavelet Transform (SWT) and Gate Recurrent Unit (GRU) deep artificial neural network. Also, by utilizing another GRU network, the proposed scheme predicts the extinction time of the secondary arc (SA) one power cycle before the complete extinction. This can increase the speed of the faulty phase reclosing in the case of a transient fault. Simulation results carried out on a 400 kV power transmission line in the EMTP-RV and MATLAB software environments illustrate that the F1 score of the proposed ASPAR in classifying the faults is 99.55 %, and its average error in predicting the extinction time of the SA based on the root mean square error (RMSE) criterion is 0.0557. Also, the superiority and high-quality performance of the proposed protection scheme are demonstrated by comparing the results with several state-of-the-art methods.

A novel phasor-based adaptive single-phase auto-reclosing scheme for transmission lines with shunt reactors

A novel phasor-based adaptive single-phase auto-reclosing scheme for transmission lines with shunt reactors

Improving protection of compensated transmission line using IoT enabled adaptive auto reclosing scheme

Abstract Protection of critical components in the power sector especially the transmission line system is very important to minimize loss of revenue, resources, and productivity. Improvement of power transfer capacity and voltage profile in smart the power grid is achieved by Series Compensation (SC). However, it poses many serious issues in the protection of compensated transmission lines. The majority of faults occurring in transmission lines are transient in nature for which service continuity can be regained by an auto-reclosing scheme. An efficient auto-reclosing scheme that can provide adaptive protection with reliable operation is required to prevent transient and permanent faults in the series compensated transmission line (SCTL). This work highlights the emulation of an Internet of Things (IoT) aided adaptive auto-reclosing scheme in association with an ESP32 controller that provides adaptive dead time control. The reclosing instance has been identified by means of a synchro-check relay. A real-time IoT-aided auto-reclosing scheme has been realized using the ESP32 controller that can generate a trip/reclosing signal instantaneously using the concepts of edge computing. The projected system has been also corroborated by simulating the modeled smart power grid network with wide variations in fault context in PSCAD. The validation of the set of rules is done in MATLAB software for the proposed auto-reclosing scheme. The extracted test outcomes of the simulation and its laboratory hardware implementation indicate an appreciable reduction in dead time which reflects the efficacy of the developed protection scheme.

Detection of secondary arc extinction and auto-reclosing in compensated AC transmission lines based on machine learning

Detecting and recognizing the secondary arc extinction is considered as a backbone of the single pole auto reclosing schemes. This paper proposes a multi-channel convolutional network to detect the secondary arc extinction during a long AC power transmission line arc fault. In contrast to the conventional methods, the proposed Machin learning-based method can automatically learn the features from the raw data given as input. Multivariate time series data of phase voltage, current and neutral reactor signals were used as the input to the proposed model. The features are extracted in the convolution layer instead of using hand-crafted feature extraction like most of the existing research. The softmax classifier is used to detect fault and secondary arc extinction. Matlab Simulink is used to simulate the test system and collect the dataset to evaluate the proposed neural network model. To verify the generalizability of the proposed architecture datasets were collected at various locations and different phase lines. The proposed algorithm was able to detect the secondary arc extinction with 98.26% accuracy and able to give signal for auto-recloser logic with the maximum window length of three cycles. The result shows that the proposed neural network architecture is accurate and robust to detect the secondary arc extinction further can be used as a signal for a single pole adaptive auto recloser scheme.

Adaptive single-phase auto-reclosing scheme based on the moving average filter-quadrature signal generator for transmission lines with shunt reactors

An adaptive single-phase auto-reclosing method based on the moving average filter (MAF)-quadrature signal generator (QSG) is developed to determine secondary arc extinction time for high-voltage transmission lines with shunt reactors. Firstly, the difference between permanent and transient faults is derived and analyzed by the equivalent circuit model. Then, MAF-QSG is utilized to extract these features from the fault voltage. During the second arc period, for transient fault, the fundamental component and subharmonic component with around 50 Hz are reserved by MAF-QSG; however, in the case of permanent fault, only the fundamental component is retained. Finally, the identification index and its threshold are designed above the extraction fault features. The performance of the proposed method is evaluated by simulation and field data studies, accounting for different transmission line compensation levels, transition resistances, and fault location conditions.

A continuous wavelet and fast fourier transform-based single-phase adaptive auto-reclosing scheme for ehv transmission lines

A continuous wavelet and fast fourier transform-based single-phase adaptive auto-reclosing scheme for ehv transmission lines

Setting Free Fault Location for Three-Terminal Hybrid Transmission Lines Connected With Conventional and Renewable Resources

Three-terminal hybrid transmission lines (TTHTLs) are attractive from both environmental and commercial view. Hybrid transmission lines are growing due to urbanization, connecting an industrial load and renewable integration. A TTHTL comprises sections of both overhead lines and underground/subsea cables or overhead lines with different X/R ratios. Faulted section identification (FSI) is key for defining the adaptive/selective auto-reclosing scheme and estimation of the fault location for TTHTLs. In this paper, FSI and fault location algorithms are proposed without using the parameters of any line section. Novelty of the methodology lies in a two-stage approach to the problem. In the first stage, series impedance parameters of all the sections are calculated using closed loop formulae. These parameters are then utilized in identifying the faulted section. In the second stage, the above calculated line section parameters and faulted section are used to estimate complete line parameters including shunt capacitance and subsequently the fault location. The advantage of the proposed method is that it does not require an initial guess of the line section parameters, is non-iterative in the first stage, and provides correct fault section identification for TTHTLs. These features make it suitable for designing the selective auto-reclosing protection scheme for the TTHTLs within traditional protection relaying hardware. More importantly, the series impedance parameters calculated in the first stage constitute good initialization values for the non-linear problem of estimating the complete line parameters. This results in better convergence of the algorithm and accurate parameter estimation. The developed solution is verified using the PSCAD/EMTDC simulations for TTHTLs connected with conventional and different inverter-based renewable resources. The performance of the proposed solution is compared with commercially available solutions, and it is found to be accurate. This solution is amenable for implementation in line differential protection relays without additional infrastructural changes.

An Adaptive Reclosing Scheme Based on Phase Characteristics for MMC-HVDC Systems

To improve the reliability of power supply, reclosing schemes are required after transient faults, which commonly occur in overhead line based high voltage DC (HVDC) systems. However, in the event of permanent faults, the auto-reclosing scheme may cause a severe strike. To avoid the severe impacts caused by permanent faults, the fault type should be discriminated before activating the reclosing scheme. Therefore, an adaptive reclosing scheme based on phase characteristics is proposed in this paper. Firstly, the modulation of a periodic voltage by actively controlling the hybrid DC circuit breaker (DCCB) is introduced. Then, a cascaded π equivalent model and its decoupling algorithm are presented to analyze the frequency-domain characteristics of the measured impedance of the coupled overhead lines. From the frequency-domain characteristics, the frequency of the periodic detecting voltage is determined to analyze the phase features of the measured impedance at primary frequency. The permanent or transient faults can thus be accurately identified by using these different phase characteristics, with negligible influence on the healthy lines. In addition, the proposed scheme is robust to various fault resistances, leading to improved reliability. The effectiveness of the proposed scheme is verified in PSCAD/EMTDC.

Leveraging existing relays to improve single phase auto-reclosing

Single-phase auto-reclosing (SPAR) is used in power systems worldwide. However, many SPAR methods do not present a practical approach for field implementation. Although manufacturers have embedded SPAR functions into their commercial relays, the closed solutions make not trivial the application of new functions/methods. Thus, in this paper, a practical approach is proposed to leverage existing relays structure aiming to improve SPAR applications. A simple and effective phasor-based single-phase auto-reclosing scheme for non-compensated transmission lines is embedded in a commercially available relay equipped with a free-form programming logic. Field recordings of single-line-to-ground (SLG) faults followed by single-phase opening of transmission lines are used in a playback test procedure for validation. The results attest the effectiveness of the implemented SPAR method, as well as the feasibility of the proposed practical approach for real-world applications.

Adaptive three-phase reclosure scheme based on the correlation of currents between compensation reactors

This study proposes a novel adaptive three-phase auto-reclosing (ATPAR) scheme for shunt-compensated transmission lines when a single- or double-phase-to-ground fault occurred, which is conducted on the correlations between the currents of shunt-reactors after the line opened. In this paper, the currents characteristics of compensation reactors are analyzed firstly through fault boundary condition theoretical, then, Pearson correlation coefficient (PCC) is used to construct criterions for identifying fault nature and fault cleared time. The proposed ATPAR scheme is implemented on a 230 kV-60 Hz IEEE 9-BUS power simulation system by using ATPDraw, and various faults which considered different fault conditions are simulated. The extensive simulation results verify the efficiency and reliability of the proposed ATPAR scheme.

Improvement of Transient Stability of the Power Networks by an Intelligent Autoreclosing Scheme in the Presence of Synchronous-Based DGs

This article presents an adaptive autoreclosing scheme to preserve the network stability in postfault scenarios for the power grids equipped with synchronous-based distributed generations (SBDGs). Based on the precise fault location information, the proposed adaptive reclosing strategy will classify all the fault events in either reclosing or block reclosing zones. Furthermore, the proposed intelligent autoreclosing scheme will ensure safe and stable network operation by preventing hazardous futile reclosing attempts against persistent faults in forestry or densely populated areas due to serious safety concerns. The swift fault removal by the associated protective devices (PDs) will assist in ensuring the stable operation of the power grid after the fault clearance. If the fault is in the reclosing zones, the adaption of the proposed scheme will permit the reclosing at an appropriate instant to preserve the network stability against momentary faults. However, it will also ensure quick fault clearance by permitting the associated PD to directly operate against the permanent faults by disabling the fast operation of the autorecloser. The validation of the proposed protection strategy has been carried out using the IEEE standardized test system with multiple SBDG units to demonstrate its effectiveness in comparison with the conventional reclosing practices. A comparative analysis has been presented to illustrate the efficacy of the proposed scheme to reduce substantially the postfault swings for different fault events.

Fast and Complete Mitigation of Residual Flux in Current Transformers Suitable for Auto-Reclosing Schemes Using Jiles-Atherton Modeling

Accurate measurement of electrical currents cannot be done when the core of current transformers (CTs) is saturated. One of the reasons that causes saturation of a CT is the activation of the auto-reclose function for the circuit breaker. When the circuit breaker is switched off, a residual flux will remain in the CT core, and when the circuit breaker is reconnected, this residual flux may cause saturation of the CT core. It is necessary to remove the residual flux in an auto-reclosing scheme. In the auto-reclosing scheme, due to the short time interval between each reclosing shot of the circuit breaker, only methods that have a high-speed operation should be used to mitigate the residual flux to prevent CT core saturation. This paper introduces a fast and complete demagnetization method based on Jiles-Atherton magnetic modeling to mitigate the residual flux in the CT core. The advantages of this method are high-speed performance, independent of the CT characteristics, high accuracy and high reliability against the secondary open circuit. To evaluate the efficacy of the proposed method, software simulations and laboratory experiments are performed on a 63kV, 300A/5A CT. The results are presented and analyzed.

Adaptive Single-Pole Auto-Reclosing Scheme Based on Secondary Arc Voltage Harmonic Signatures

This paper presents an advanced adaptive single-pole auto-reclosing (ASPAR) scheme based on harmonic characteristics of the secondary arc voltage. For analysis of the harmonics, short-time Fourier transform (STFT), which is a universal signal processing tool for transforming a signal from the time domain to the frequency domain, is utilized. STFT is applied to extract the abnormal harmonic signature from the voltage waveform of a faulted phase when a transient or permanent fault occurs on a power transmission line. The proposed scheme uses the total harmonic distortion (THD) factor to determine the fault type based on the variation and distortion characteristics of the harmonics. Harmonic components in the order of odd/even are also utilized to detect the secondary arc extinction time and guide the reclosing operation. Based on these factors, two coordinated algorithms are proposed to reduce the unnecessary dead time in conventional auto-reclosing methods and enable an optimal reclosing operation in the event of a single-pole to ground fault. The proposed ASPAR scheme is implemented using the electromagnetic transient program (EMTP), and various simulations are conducted for actual 345 and 765 kV Korean study systems.

Phasor-Based Single-Phase Auto-Reclosing Scheme for Non-Compensated Transmission Lines

An approach to detect the secondary arc extinction is proposed here for single-phase auto-reclosing of non-compensated transmission lines. It consists on the analysis of the line side voltage phasors in the modal domain to safely and rapidly identify the presence and the extinction of secondary arc in the line. The procedure can also determine the arc re-ignition if it occurs during the line dead time. Since the proposed approach requires only the voltage phasors at one line terminal, it can be easily implemented in existing Intelligent Electronic Devices (IEDs) with no additional hardware or equipment requirement. Data from the Brazilian Power Grid were used to generate the case studies through the Electromagnetic Transients Program (EMTP). Moreover, field recordings were used to validate the proposed approach. A qualitative comparison with existing methods was accomplished and the obtained results reveal the proposed scheme efficiency, reliability and robustness.

A Comprehensive Review of Auto-Reclosing Schemes in AC, DC, and Hybrid (AC/DC) Transmission Lines

The integration of distributed generators has changed the paradigm of modern power transmission systems. To cope with energy demands, electrical networks emphasize the efficient utilization of power transmission. Thus, high-voltage DC (HVDC) and hybrid (AC/DC) transmission systems are also getting attention owing to their high efficiency in addition to the widely adopted high-voltage AC (HVAC) systems. Most faults in the bulk of transmission lines are temporary or intermittent. Auto-reclosing schemes can be used to prevent these faults. However, conventional auto-reclosing schemes based on constant dead time cannot recognize the fault nature within the assigned duration. Consequently, the accuracy of power grids can be compromised. Therefore, adaptive auto-reclosing schemes are convenient for overcoming the issues caused by the rapid restoration of faulty power lines. This can enhance system reliability and avoid power failures and blackouts. This study is based on a systematic, detailed, and thorough research review of the existing auto-reclosing schemes in all three power transmission lines, i.e., AC, DC, and hybrid (AC/DC). Subsequently, a critical analysis has been performed to assess the pros and cons of each existing adaptive auto-reclosing scheme. Finally, future recommendations are presented to improve adaptive auto-reclosing schemes in each medium.

Adaptive reclosing strategy for single outgoing line of converter-interfaced wind park using distance relaying algorithm

The 110 kV single outgoing line powered by wind generation usually adopts tripolar tripping and three-phase auto-recloser. The electrical quantities of the single line attenuate quickly after fault tripping, which makes it difficult to identify fault properties during the dead time. Also, due to the high voltage or frequency protection, the converter-interfaced wind generation is prone to be blocked after tripolar tripping. The machine-side circuit breaker is then reclosed temporarily. A fast adaptive auto-reclosing scheme is proposed for three-phase tripping scenarios by injecting sinusoidal currents from interface converter to the faulty line. By re-activating pulse width modulation (PWM) for a very short time, the interface converter works as STATCOM to regulate the output voltage and then an active current injection is realized. Improved distance relaying algorithm is deduced in this injection scenario to locate the fault and achieve fault property identification. After the confirmation of arc extinction, the triggering control of interface converter will be re-activated and the circuit breaker will be reclosed to restore power transmission. The proposed fast three-phase reclosing scheme is validated in PSCAD/EMTDC and the simulation results show the accuracy of fault identification and short reclosing time.

Adaptive Single-Phase Auto-Reclosing Approach for Shunt Compensated Transmission Lines

Single-phase auto-reclosing (AR) scheme is widely employed in extra high voltage (EHV) transmission networks to quench transient faults without completely removing the faulted transmission line (TL). Long EHV TLs are commonly equipped with shunt reactors to reduce the Ferranti effect overvoltages. It is common practice to disconnect these reactors under the heavy load periods during the year. Considering this point, the AR technique should be able to work properly not only when the TL shunt reactors are in service, but also when they are disconnected. This paper puts forward a novel adaptive single-phase AR approach for shunt compensated TLs based on the general mathematical model of faulted phase voltage waveform after the line isolation, which is obtained by analytical analysis conducted on the TL's equivalent circuit. The effect of capacitor voltage transformer (CVT) on the voltage measurement is taken into account using a proper model for the CVT. Performing some data processing on the faulted phase measured voltage, useful features are extracted which are used by the support vector machine classifier to reliably detect the arc extinction instant. The proposed approach performance is evaluated by extensive simulation studies, accounting for different TL compensation schemes, transposition configurations, and arc conditions.

Protection Coordination of Radial Distribution Networks Connected with Distributed Generation Considering Auto-reclosing Schemes by Resistive Superconducting Fault Current Limiters

AbstractRadial distribution networks are normally protected against fault currents by fuses and reclosers. This protection is coordinated in a way that reclosers clear temporary faults before the melting of fuses and fuses melt to clear permanent faults. Distribution networks, which are recently connected with distributed generations (DGs), incur a variety of issues that are certainly worthy of closer considerations. One of these issues is the operation of protection devices. Recloser-fuse coordination may be lost when DGs are integrated with distribution networks due to the effect of current flowing from DGs during fault period and the breaking of the radiality nature of these networks. The impact of DGs on recloser-fuse coordination depends on penetration level, location, and type of DG. Recloser-fuse coordination of radial distribution networks connected with DGs can be kept by connecting resistive superconducting fault current limiter (R-SFCL) in series with the DG to limit the fault current contribution of DG during the fault period. However, when considering the auto-reclosing scheme of the recloser, recloser-fuse coordination may be lost even if R-SFCL is connected. This paper shows the effectiveness of R-SFCL to restore recloser-fuse coordination without considering auto-reclosing scheme. It also proposes solution methods based on three different configurations of R-SFCL to maintain recloser-fuse coordination when auto-reclosing scheme is considered. Simulation results illustrate the effectiveness of the proposed configurations of R-SFCL to keep recloser-fuse coordination. All simulations are performed using MATLAB/Simulink package.

Adaptive Comprehensive Auto-Reclosing Scheme for Shunt Reactor-Compensated Transmission Lines

After a tripping of a transmission line, if the fault is transient, fault arc may be extinguished in three different kind of periods: initial, middle, and ending period. Existing adaptive auto-reclosing (AAR) schemes cannot cover all kind of situations, which seriously affects application of those AAR schemes. An adaptive comprehensive auto-reclosing (ACAR) scheme for shunt reactor-compensated transmission lines is proposed in this paper. Based on a novel partial tripping method (PTM), two criteria are included in the proposed ACAR scheme. The first criterion is based on fault phase reactive power low-frequency component (RPLC), which can deal with faults extinguished in initial and middle periods; and the other criterion is based on high-frequency component distortion (HCD), which can deal with faults extinguished in middle and ending periods. The theoretical analysis and simulation experiments based on PSCAD/EMTDC indicate that, for different fault categories, locations, and transition resistances, the proposed ACAR can distinguish transient faults from permanent ones and determine the fault extinction time rapidly and accurately.

Adaptive Autoreclosing Scheme for Line-to-Line Nongrounded Faults on Double-Circuit Transmission Lines Based on Phase-to-Phase Reactive Power

Double-circuit transmission lines play a very important role in electric power transmission. When a line-to-line nongrounded fault occurs on double-circuit transmission lines, for traditional tripping and reclosing methods, tripping of all six phases may cause power system instability, and fixed time autoreclosing may reclose the double-circuit transmission lines to a nonextinguished fault. In this paper, a novel tripping strategy is proposed; when a line-to-line nongrounded fault occurs, some part of the electric power can be transmitted after tripping, and many kinds of nongrounded faults can be equivalent to a single-phase to ground fault. Furthermore, reactive power characteristics are adopted to determine the fault extinction. Finally, an adaptive autoreclosing scheme for line-to-line nongrounded faults on double-circuit transmission lines based on phase-to-phase reactive power is proposed. The accuracy and feasibility of the propose method are verified by relevant simulation experiments, and multiple operation conditions are considered.