scholarly journals Insulation Performance Analysis of Field Aged and New MV XLPE Cables Using Various Diagnostic Techniques

2021 ◽  
Vol 294 ◽  
pp. 02008
Author(s):  
Yousef Al-Onazi ◽  
Nissar Wani ◽  
Abdulrahman Al-Arainy ◽  
Yasin Khan
Keyword(s):  
Power Systems ◽  
Experimental Studies ◽  
Dissipation Factor ◽  
Diagnostic Techniques ◽  
Transmission Networks ◽  
Medium Voltage ◽  
Normal Life Span ◽  
Power Utilities ◽  
Non Destructive ◽  
Insulation Condition

Cross-linked polyethylene (XLPE) cables are widely used in the distribution and transmission networks of power systems. The insulation materials of these cables are stressed by the over voltages and are also exposed to various environmental conditions. This leads the power cables to degrade during their normal life span. Therefore, it would be advantageous for the power utilities to acquire the cable’s insulation condition frequently during their operation. In this paper, experimental studies were carried out on short sections of field aged as well as un-aged medium voltage (MV) XLPE cables to investigate the insulation condition using non-destructive diagnostic techniques such as Dissipation Factor (DF), Isothermal Relaxation Current (IRC), and Partial Discharge (PD) characteristics at 60Hz. From this set of experiments, different parameters will be used to analyze the dielectric response and the insulation condition. Finally, the results show how the VLF dissipation factor works efficiently to assess cable aging.

scholarly journals Thermal Analysis of the Medium Voltage Cable

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4164
Author(s):  
Tomasz Szczegielniak ◽  
Dariusz Kusiak ◽  
Paweł Jabłoński
Keyword(s):  
Temperature Distribution ◽  
Analytical Method ◽  
Good Accuracy ◽  
Proximity Effects ◽  
Electrical Performance ◽  
Power Cables ◽  
Power Losses ◽  
Transmission Networks ◽  
Medium Voltage ◽  
Cable Lines

The use of high voltage power cables in distribution and transmission networks is still increasing. As a result, the research on the electrical performance of cable lines is still up to date. In the paper, an analytical method of determining the power losses and the temperature distribution in the medium voltage cable was proposed. The main feature of the method is direct including the skin and proximity effects. Then the Joule law is used to express the power losses in the conductor and screen, and the Fourier-Kirchhoff equation is applied to find out the temperature distribution in the cable. The research was focused on a cable with isolated screen and return current in the screen taken into account. The proposed method was tested by using the commercial COMSOL software(5.6/COMSOL AB, Stockholm, Sweden) as well as by carrying out laboratory measurements. Furthermore, the results obtained via the proposed method were compared with those given in literature. The differences between the temperature values calculated by the analytical method, numerical computations and obtained experimentally do not exceed 10%. The proposed analytical method is suitable in prediction the temperature of the power cables with good accuracy.

Photometric Method of Diagnosis of Bearing Units Operating with Hydrocarbon Mixtures

2018 ◽  
Vol 284 ◽  
pp. 1342-1348
Author(s):  
E.N. Gryadunova ◽  
R.N. Polyakov ◽  
N.V. Tokmakov
Keyword(s):  
Experimental Studies ◽  
Physicochemical Process ◽  
Bright Spot ◽  
Photometric Method ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Internal Damage ◽  
Hydrocarbon Mixtures ◽  
Bearing Unit ◽  
Non Destructive

The article is devoted to the diagnosis of bearing units working with hydrocarbon mixtures. The diagnostic is based on the photometric method. This method allows you to determine the internal damage to the bearing unit at the stage of the appearance of the microcrack. The photometric method is based on changing the color of the indicator fabric. As the indicator substance, a bromine solution was used which had a dark brown color. If there is a leak, the hydrocarbon reacts with bromine molecules and a bright spot appears on the tape. Indicator fabric is applied to the bearing unit during assembling.The material of the article contains a model of the physicochemical process, which is the basis of the photometric method. Various stages of leakage of hydrocarbon mixtures through microcracks were studied. The results of the experimental studies are consistent with the theoretical propositions. The proposed diagnostic method can be used as a method for non-destructive testing of bearing units.

Sign in / Sign up

Export Citation Format

Share Document