A novel adaptive zero-sequence current protection for low resistance grounding system

2016 ◽  
Author(s):  
Xiaobin Guo ◽  
Bowen Han ◽  
Jinyong Lei ◽  
Gang Wang
Keyword(s):  
Grounding System ◽  
Low Resistance ◽  
Zero Sequence

scholarly journals Faulty Feeder Identification Based on Data Analysis and Similarity Comparison for Flexible Grounding System in Electric Distribution Networks

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 154
Author(s):  
Kangli Liu ◽  
Sen Zhang ◽  
Baorun Li ◽  
Chi Zhang ◽  
Biyang Liu ◽  
...  
Keyword(s):  
Wavelet Packet ◽  
Distribution Networks ◽  
Sampled Data ◽  
Grounding System ◽  
Electric System ◽  
Identification Method ◽  
Ground Fault ◽  
Correlation Degree ◽  
Zero Sequence ◽  
Electric Distribution

Reliability and safety are the most important indicators in the electric system. When a ground fault occurs, the electrical equipment and personnel will be greatly threatened. Due to the zero-sequence voltage/current sensor networks applied in the system, the fault identification and diagnosis technology are developing rapidly, including the application of ground fault suppression. A flexible grounding system (FGS) is a new technology applied to arc extinguishing in medium and high voltage electric distribution networks. Its characteristic is that when the single-phase ground fault occurs, the power-electronic-based device is put into the electric system to compensate and suppress the ground point current to be close to zero in a very short time. In order to implement the above process, the corresponding faulty feeder identification method needs to meet the requirements of rapidity and accuracy. In this article, based on the real-time sampled data from the zero-sequence current/voltage sensors, an improved faulty feeder identification method combining wavelet packet transform (WPT) and grey T-type correlation degree is proposed, which features both accuracy and rapidity. The former is used to reconstruct the transient characteristic signal, and the latter is responsible for calculating and comparing the similarity of relative variation trend. Simulation results verify the rationality and effectiveness of the proposed method and analysis.

scholarly journals Detection of broken conductor with ground contact faults in medium voltage power networks

2006 ◽  
Vol 19 (3) ◽  
pp. 429-438 ◽  
Author(s):  
Dumitru Toader ◽  
Stefan Haragus ◽  
Constantin Blaj
Keyword(s):  
Ground Contact ◽  
Power Networks ◽  
Grounding System ◽  
Medium Voltage ◽  
Protective System ◽  
Zero Sequence ◽  
Technical Solutions ◽  
Zero Sequence Voltage ◽  
Types Of Faults ◽  
Good Agreement

A major problem concerning the operation of medium voltage power networks refers to the neutral-point grounding system. Several technical solutions are in use, none of them being completely satisfactory. One criterion to appreciate the efficiency of a grounding system is the ability of the network?s protective system to accurately detect various types of faults such as broken conductor with ground contact faults. This type of fault make a relatively important figure (3 to 10 %) in the total faults statistics for a medium voltage network. In order to detect such faults, the sensed variables are the zero-sequence voltage and the neutral-grounding current. In this paper an analytical and computational analysis is performed to see how various fault and network parameters affect these variables, assuming different grounding systems. Measurements made in two real medium voltage networks show good agreement with the theoretical results.

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