The comparative analysis of selected overvoltage protection measures for medium voltage overhead lines with covered conductors

2017 ◽  
Author(s):  
Michal Borecki ◽  
Jacek Starzynski ◽  
Zuzanna Krawczyk
Keyword(s):  
Comparative Analysis ◽  
Protection Measures ◽  
Overhead Lines ◽  
Medium Voltage ◽  
Overvoltage Protection ◽  
Covered Conductors

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 Study on the Effect of Helium on the Dielectric Strength of Medium-Voltage Vacuum Interrupters

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3742
Author(s):  
Paweł Węgierek ◽  
Michał Lech ◽  
Damian Kostyła ◽  
Czesław Kozak
Keyword(s):  
Comparative Analysis ◽  
Test Object ◽  
Pressure Range ◽  
Dielectric Strength ◽  
Working Pressure ◽  
Medium Voltage ◽  
Vacuum Interrupter ◽  
Working Medium ◽  
Pure Helium ◽  
Insulating Properties

This paper presents the results of a comparative analysis of the dielectric strength of disconnecting vacuum interrupters operating on air and helium. The breakdown voltage Ud was measured in the pressure range from 8.0 × 10−4 Pa to 3.0 × 101 Pa for air and from 8.0 × 10−4 Pa to 7.0 × 102 Pa for helium, while varying the interelectrode distance from 1.0 to 5.0 mm. Dedicated laboratory workstations were used to determine the actual pressure values in the vacuum interrupters tested and to precisely measure and record the dielectric strength results of the test object. It was found that the helium-filled vacuum interrupter maintains its full dielectric strength in significantly larger pressure ranges, while the air-filled vacuum interrupter loses its insulating properties. Thus, it is possible to make vacuum interrupters based on the working medium associated with pure helium, with larger working pressure ratings. Under such conditions, it is easier to maintain the tightness of the device and to limit cut-off currents and overvoltages associated with vacuum switchgear.

Sign in / Sign up

Export Citation Format

Share Document