scholarly journals Verification of a Novel Method of Detecting Faults in Medium-Voltage Systems with Covered Conductors

2017 ◽  
Vol 24 (2) ◽  
pp. 277-288 ◽  
Author(s):  
Stanislav Mišák ◽  
Štefan Hamacek ◽  
Mikołaj Bartłomiejczyk
Keyword(s):  
Relay Protection ◽  
Overhead Lines ◽  
Medium Voltage ◽  
New Methods ◽  
Protection Systems ◽  
Novel Method ◽  
Covered Conductors ◽  
Tree Branch ◽  
New System ◽  
Three Phases

AbstractThis paper describes the use of new methods of detecting faults in medium-voltage overhead lines built of covered conductors. The methods mainly address such faults as falling of a conductor, contacting a conductor with a tree branch, or falling a tree branch across three phases of a medium-voltage conductor. These faults cannot be detected by current digital relay protection systems. Therefore, a new system that can detect the above mentioned faults was developed. After having tested its operation, the system has already been implemented to protect mediumvoltage overhead lines built of covered conductors.

scholarly journals Towards the Text Compression Based Feature Extraction in High Impedance Fault Detection

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2148 ◽  
Author(s):  
Tomáš Vantuch ◽  
Michal Prílepok ◽  
Jan Fulneček ◽  
Roman Hrbáč ◽  
Stanislav Mišák
Keyword(s):  
Partial Discharge ◽  
Partial Discharges ◽  
Classification Model ◽  
Discharge Pattern ◽  
Text Compression ◽  
Overhead Lines ◽  
Medium Voltage ◽  
Similarity Estimation ◽  
High Impedance ◽  
Covered Conductors

High impedance faults of medium voltage overhead lines with covered conductors can be identified by the presence of partial discharges. Despite it is a subject of research for more than 60 years, online partial discharges detection is always a challenge, especially in environment with heavy background noise. In this paper, a new approach for partial discharge pattern recognition is presented. All results were obtained on data, acquired from real 22 kV medium voltage overhead power line with covered conductors. The proposed method is based on a text compression algorithm and it serves as a signal similarity estimation, applied for the first time on partial discharge pattern. Its relevancy is examined by three different variations of classification model. The improvement gained on an already deployed model proves its quality.

New solutions in EDP Distribuicao medium voltage overhead lines

2009 ◽  
Author(s):  
A. Cardoso ◽  
J. Cardoso ◽  
J. Figueiredo ◽  
N. Mendes
Keyword(s):  
Overhead Lines ◽  
Medium Voltage

scholarly journals Photovoltaic Maximum Penetration Limits on Medium Voltage Overhead and Underground Cable Distribution Feeders: A Comparative Study

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3843
Author(s):  
Sultan Sh. Alanzi ◽  
Rashad M. Kamel
Keyword(s):  
Power System ◽  
Power Factor ◽  
Distribution System ◽  
Power Flow ◽  
Underground Cables ◽  
Overhead Lines ◽  
Medium Voltage ◽  
Load Power ◽  
Bus Voltage ◽  
Pv Penetration

This paper investigates the maximum photovoltaic (PV) penetration limits on both overhead lines and underground cables medium voltage radial distribution system. The maximum PV penetration limit is estimated considering both bus voltage limit (1.05 p.u.) and feeder current ampacity (1 p.u.). All factors affect the max PV penetration limit are investigated in detail. Substation voltage, load percentage, load power factor, and power system frequency (50 Hz or 60 Hz) are analyzed. The maximum PV penetration limit associated with overhead lines is usually higher than the value associated with the underground cables for high substation voltage (substation voltage = 1.05 and 1.04 p.u.). The maximum PV penetration limit decreases dramatically with low load percentage for both feeder types but still the overhead lines accept PV plant higher than the underground cables. Conversely, the maximum PV penetration increases with load power factor decreasing and the overhead lines capability for hosting PV plant remains higher than the capability of the underground cables. This paper proved that the capability of the 60-Hz power system for hosting the PV plant is higher than the capability of 50 Hz power system. MATLAB software has been employed to obtain all results in this paper. The Newton-Raphson iterative method was the used method to solve the power flow of the investigated systems.

scholarly journals Power supply risk assessment method for relay protection system faults

2016 ◽  
Vol 65 (4) ◽  
pp. 803-814
Author(s):  
Si Tuyou ◽  
Wu Jiekang ◽  
Yuan Weideng ◽  
Du Anan
Keyword(s):  
Power Supply ◽  
Distribution Systems ◽  
Probability Model ◽  
Relay Protection ◽  
Assessment Method ◽  
Protection System ◽  
Supply Risk ◽  
Load Power ◽  
Risk Assessment Method ◽  
Protection Systems

Abstract The influence and the potential risk due to hidden faults of a relay protection system on power supply in distribution systems are paid more and more attention to. A probability analysis method is used to analyse fault characteristics and action mechanism of dominant faults, hidden misoperation and non-operation of the relay protection systems, and failure probability model of relay protection system is constructed and simplified. The effects of dominant faults, hidden misoperation and non-operation of the relay protection systems on the reduced power supply load power are analysed, and a probabilistic model for reduced power supply load power is constructed by three parts corresponding to dominant faults, hidden misoperation and non-operation. A probability calculation method of power supply risk occurrence due to hidden faults of relay protecttion system is proposed considering the fault probability of the relay protection systems, the frequency of the hidden faults occurring in operation period, the reduced power supply load power or load power outage, and the connection mode of the in-lines, out-lines and transformers in a substation. The feasibility and applicability of the proposed method for estimation of risk value probability of the relay protection systems is verified by two studied examples.

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