scholarly journals Research on the Protection Scheme of DG Interconnection Transition Mode Based on Decoupling Zero Sequence

2016 ◽  
Vol 9 (8) ◽  
pp. 65-76
Author(s):  
Xia Lin ◽  
Yuping Lu ◽  
Yao Li ◽  
Guibin Zou
Keyword(s):  
Transition Mode ◽  
Protection Scheme ◽  
Zero Sequence

scholarly journals Zero-Sequence Differential Current Protection Scheme for Converter Transformer Based on Waveform Correlation Analysis

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1814
Author(s):  
Tao Zheng ◽  
Xinhui Yang ◽  
Xingchao Guo ◽  
Xingguo Wang ◽  
Chengqi Zhang
Keyword(s):  
Correlation Coefficient ◽  
Neutral Current ◽  
Current Transformer ◽  
Neutral Point ◽  
Inrush Current ◽  
Protection Scheme ◽  
Internal Fault ◽  
Zero Sequence ◽  
Fault Removal ◽  
Differential Current

Through the analysis of the recovery inrush current generated by the external fault removal of the converter transformer, it is pointed out that the zero-sequence current caused by the recovery inrush may result in the saturation of the neutral current transformer (CT), whose measurement distortion contributes to the mis-operation of zero-sequence differential current protection. In this paper, a new scheme of zero-sequence differential current protection based on waveform correlation is proposed. By analyzing the characteristics of zero-sequence current under internal fault, external fault and external fault removal, the waveform correlation of the zero-sequence current measured at the terminal of the transformer and the zero-sequence current measured at the neutral point of the transformer is used for identification. The polarity of the CT is selected to guarantee the zero-sequence currents at the terminal and neutral point of the transformer exhibit a "ride through" characteristic under external fault, then the waveform similarity is high, and the correlation coefficient is positive. On the other hand, when internal fault occurs, zero-sequence current waveforms on both sides differ from each other largely, and the correlation coefficient is negative. Through a large number of simulations verified by PSCAD/EMTDC, this criterion can accurately identify internal and external faults, exempt from effects of the recovery inrush. Moreover, it presents certain ability for CT anti-saturation.

scholarly journals IEC 61850-Based Centralized Protection against Single Line-To-Ground Faults in Ungrounded Distribution Systems

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 722
Author(s):  
Soon-Ryul Nam ◽  
Woong-Hie Ko ◽  
Sopheap Key ◽  
Sang-Hee Kang ◽  
Nam-Ho Lee
Keyword(s):  
Computer Aided Design ◽  
Distribution Systems ◽  
Electronic Device ◽  
Single Line ◽  
International Electrotechnical Commission ◽  
Iec 61850 ◽  
Protection Scheme ◽  
Zero Sequence ◽  
Intelligent Electronic Device ◽  
Electro Magnetic

We developed an International Electrotechnical Commission (IEC) 61850-based centralized protection scheme to prevent single line-to-ground (SLG) faults in the feeders and busbars of ungrounded distribution systems. Each feeder intelligent electronic device (IED) measures its zero-sequence current and voltage signals and periodically transmits zero-sequence phasors to a central IED via a Generic Oriented Object Substation Event message. Using the zero-sequence phasors, the central IED detects SLG faults in feeders and busbars. To achieve centralized protection, angle differences between the zero-sequence currents and voltage phasors are exploited, and their calculation compensates for data desynchronization. The feeder IEDs were implemented using the MMS-EASE Lite library, while the transmitted zero-sequence phasors were calculated based on fault signals simulated by Power System Computer Aided Design / Electro-Magnetic Transient Design and Control (PSCAD/EMTDC). The central IED determined if the SLG fault was in a feeder or busbar by aggregating and analyzing the zero-sequence phasors received from the feeder IEDs. The results confirmed the validity and efficiency of our centralized protection scheme.

scholarly journals Mutual Coupling Compensation Techniques Used for Distance Protection of Parallel Lines

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1982
Author(s):  
Michael O Donovan ◽  
Noel Barry ◽  
Joe Connell ◽  
Eoin Cowhey
Keyword(s):  
Mutual Coupling ◽  
Coupling Effect ◽  
Parallel Line ◽  
Distance Protection ◽  
Coupling Impedance ◽  
Distance Relay ◽  
Protection Relay ◽  
Protection Scheme ◽  
Parallel Lines ◽  
Zero Sequence

When a distance relay protects a transmission line located on a dual circuit tower, a coupling effect will occur between the two circuits. Transposition of the circuits can reduce the mutual impedances, but this does not cater to the zero-sequence mutual coupling impedance during earth faults. As a result, the impedance measured by a distance relay under phase-to-earth fault conditions in these circumstances will not represent the correct impedance to the fault point unless these effects are taken into account. On multi-circuit lines, primarily if they operate in parallel, a zero-sequence mutual coupling should be considered when calculating settings for distance protection function. A 220 kV parallel line sharing the same tower was analysed using DigSilent Power Factory in the simulations. Phase-to-earth faults in different configurations were analysed on this system, and the reach of the protection relay was then estimated for operation. The results confirm how a protection relay can overreach and underreach in a distance protection scheme due to the influence of mutual coupling.

scholarly journals Combined DFT and Fuzzy Based Faulty Phase Selection and Classification in a Series Compensated Transmission Line

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Praveen Kumar Mishra ◽  
Anamika Yadav
Keyword(s):  
Transmission Line ◽  
Fault Location ◽  
Fault Classification ◽  
Testing Time ◽  
Heavy Load ◽  
Phase Selection ◽  
Protection Scheme ◽  
Fault Resistance ◽  
Zero Sequence ◽  
Series Capacitor

The conventional distance protection scheme malfunctions sometimes in case of a fixed series capacitor compensated transmission line due to the change in relaying impedance of the protected line during faulty conditions. In order to mitigate this problem, a combined discrete Fourier transform and fuzzy (CDFTF) based algorithm has been proposed in this paper. This method has been tested on a 400 km, 735 kV series compensated transmission line network and WSCC 3-machine 9-bus system for all fault types using MATLAB/Simulink and PSCAD platforms, respectively. A fixed series capacitor is located at the middle of the protected line. The fundamental components of phase currents, phase voltages, and zero-sequence current are fed as inputs to the proposed scheme. The fault detection, faulty phase selection, and fault classification are achieved within 1/2–1 cycle of power frequency. The proposed CDFTF-based scheme is less complex and is better than other data mining techniques which require huge training and testing time. Test results corroborate the proposed scheme reliability with wide variations in fault location, fault resistance, fault inception angle, evolving faults, compensation level, and heavy load interconnection. The results discussed in this work indicate that the proposed technique is resilient to wide variations in fault and system conditions.

scholarly journals Alienation Coefficient and Wigner Distribution Function Based Protection Scheme for Hybrid Power System Network with Renewable Energy Penetration

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1120 ◽  
Author(s):  
Sheesh Ram Ola ◽  
Amit Saraswat ◽  
Sunil Kumar Goyal ◽  
Virendra Sharma ◽  
Baseem Khan ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Solar Energy ◽  
Power System ◽  
Wigner Distribution ◽  
Discrete Wavelet ◽  
Protection Scheme ◽  
Double Phase ◽  
Variable Nature ◽  
Zero Sequence ◽  
Hybrid Grid

The rapid growth of grid integrated renewable energy (RE) sources resulted in development of the hybrid grids. Variable nature of RE generation resulted in problems related to the power quality (PQ), power system reliability, and adversely affects the protection relay operation. High penetration of RE to the utility grid is achieved using multi-tapped lines for integrating the wind and solar energy and also to supply loads. This created considerable challenges for power system protection. To overcome these challenges, an algorithm is introduced in this paper for providing protection to the hybrid grid with high RE penetration level. All types of fault were identified using a fault index (FI), which is based on both the voltage and current features. This FI is computed using element to element multiplication of current-based Wigner distribution index (WD-index) and voltage-based alienation index (ALN-index). Application of the algorithm is generalized by testing the algorithm for the recognition of faults during different scenarios such as fault at different locations on hybrid grid, different fault incident angles, fault impedances, sampling frequency, hybrid line consisting of overhead (OH) line and underground (UG) cable sections, and presence of noise. The algorithm is successfully tested for discriminating the switching events from the faulty events. Faults were classified using the number of faulty phases recognized using FI. A ground fault index (GFI) computed using the zero sequence current-based WD-index is also introduced for differentiating double phase and double phase to ground faults. The algorithm is validated using IEEE-13 nodes test network modelled as hybrid grid by integrating wind and solar energy plants. Performance of algorithm is effectively established by comparing with the discrete wavelet transform (DWT) and Stockwell transform based protection schemes.

The Relay Protection Scheme for Distribution Network with Distributed Generations

2012 ◽  
Vol 433-440 ◽  
pp. 4046-4052
Author(s):  
Shi En He ◽  
Xin Zhou Dong ◽  
Zhi Qian Bo ◽  
Jia Le Suo Nan
Keyword(s):  
Distribution Network ◽  
Relay Protection ◽  
Distribution Grid ◽  
Hydro Power ◽  
Power Sources ◽  
Protection Scheme ◽  
Entire Line ◽  
Zero Sequence ◽  
Speed Up ◽  
Double Circuit Line

Three-zone distance protection and four-zone zero sequence over-current protection are traditional relay protection schemes used for tapped-lines that connect distributed photovoltaic, wind, and small hydro power sources into a distribution network. These protection schemes cannot quickly clear the faults that occur at the end of the protected line. A newly developed non-communication protection scheme for tapped-line and double-circuit line tested at Gansu Power Grid can significantly speed up fault clearing at the end of the lines, and achieve fast tripping for the entire line section. This protection scheme also shows advantageous results for distribution grid with distributed generation.

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