scholarly journals Induced sheath voltages in 110 kV power cables – case study

2015 ◽  
Vol 64 (3) ◽  
pp. 361-370 ◽  
Author(s):  
Stanislaw Czapp ◽  
Krzysztof Dobrzynski ◽  
Jacek Klucznik ◽  
Zbigniew Lubosny
Keyword(s):  
Electric Shock ◽  
Single Point ◽  
Optimal Configuration ◽  
Power Cable ◽  
Power Cables ◽  
Local Power ◽  
Economic Aspects ◽  
Maximal Power ◽  
Cable System

Abstract This paper considers electric shock hazard due to induced sheath voltages in 110 kV power cables. The purpose of this paper is to find an optimal configuration of the power cable system, taking into account electric shock hazard and ability of the system to transfer maximal power. A computer simulations on a computer model of the local power system, comprising high voltage power cables, were carried out. This model enables to analyse various configurations of the metallic cable sheaths bonding and earthing (single-point bonding, both-ends bonding, cross-bonding) and their impact on induced voltages in the cable sheaths. The analysis presented in the paper shows, that it is possible to find an optimal configuration of the complicated power cable system, in terms of electric shock hazard, maximal power transfer as well as economic aspects.

scholarly journals Safety Issues Referred to Induced Sheath Voltages in High-Voltage Power Cables—Case Study

2020 ◽  
Vol 10 (19) ◽  
pp. 6706
Author(s):  
Stanislaw Czapp ◽  
Krzysztof Dobrzynski
Keyword(s):  
High Voltage ◽  
Electric Shock ◽  
Short Circuit ◽  
Single Point ◽  
Power Cable ◽  
Power Cables ◽  
Power Losses ◽  
Cable Line ◽  
Low Level

Load currents and short-circuit currents in high-voltage power cable lines are sources of the induced voltages in the power cables’ concentric metallic sheaths. When power cables operate with single-point bonding, which is the simplest bonding arrangement, these induced voltages may introduce an electric shock hazard or may lead to damage of the cables’ outer non-metallic sheaths at the unearthed end of the power cable line. To avoid these aforementioned hazards, both-ends bonding of metallic sheaths is implemented but, unfortunately, it leads to increased power losses in the power cable line, due to the currents circulating through the sheaths. A remedy for the circulating currents is cross bonding—the most advanced bonding solution. Each solution has advantages and disadvantages. In practice, the decision referred to its selection should be preceded by a wide analysis. This paper presents a case study of the induced sheath voltages in a specific 110 kV power cable line. This power cable line is a specific one, due to the relatively low level of transferred power, much lower than the one resulting from the current-carrying capacity of the cables. In such a line, the induced voltages in normal operating conditions are on a very low level. Thus, no electric shock hazard exists and for this reason, the simplest arrangement—single-point bonding—was initially recommended at the project stage. However, a more advanced computer-based investigation has shown that in the case of the short-circuit conditions, induced voltages for this arrangement are at an unacceptably high level and risk of the outer non-metallic sheaths damage occurs. Moreover, the induced voltages during short circuits are unacceptable in some sections of the cable line even for both-ends bonding and cross bonding. The computer simulations enable to propose a simple practical solution for limiting these voltages. Recommended configurations of this power cable line—from the point of view of the induced sheath voltages and power losses—are indicated.

scholarly journals A statistical method for stastical appraisal of the power cable conditions based on the TD and PD diagsnostics result

2019 ◽  
Vol 124 ◽  
pp. 02014
Author(s):  
T. Neier ◽  
J. Knauel ◽  
M. Bawart ◽  
D. Antipov ◽  
S. Kim
Keyword(s):  
Life Time ◽  
Distribution Networks ◽  
Power Cable ◽  
Practical Case ◽  
Power Cables ◽  
Remaining Life ◽  
Power Utilities ◽  
Underground Power Cables ◽  
Asset Managers

This study handles one of the key questions of network operators: How can the remaining life time of underground power cables be estimated? The answer to this question is explained by a new method of KEPCO Korea. When combining VLF Tan Delta (TD) and Partial Discharge (PD) diagnostic it is possible to identify and localize weak individual spots along a cable. After weak spots are cleared, the general aging condition of the cable can be evaluated and the Remaining Life Time can be estimated. The implementation of this approach in the KEPCO Distribution Networks is illustrated in a practical case study. A new tool for asset managers is available and it is expected that it will help to further develop the preventive maintenance approach by power utilities all around the world.

A Discussion on recent advances in heavy electrical plant - Underground power cables

1973 ◽  
Vol 275 (1248) ◽  
pp. 193-203 ◽  
Keyword(s):  
Power Transmission ◽  
Power Cable ◽  
Power Cables ◽  
Cable System ◽  
Insulating Materials ◽  
Cable Systems ◽  
Underground Power Cable ◽  
Underground Power Cables ◽  
Near Future ◽  
Further Development

Up to the present, effectively all underground power transmission needs have been satisfied by the use of conductors insulated with impregnated paper. In particular, in recent years, the oil-filled cable system using cellulose paper impregnated with oil under pressure has been further developed to meet all immediate and near future needs for higher voltage and higher current power transmission underground. With modem materials and technology, are there more economical solutions and can the needs of the longer future term be met? The basic electrical, thermal, mechanical and reliability constraints which are exerted upon the design of supertension underground power cable systems are considered. The limitations upon further development of the oil-filled cable system are identified. Also, indications are given of the potentials of new insulating materials and novel constructions of cable to provide more economical solutions and greater power transmission capabilities.

scholarly journals Optimization of Thermal Backfill Configurations for Desired High-Voltage Power Cables Ampacity

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1452 ◽  
Author(s):  
Stanislaw Czapp ◽  
Filip Ratkowski
Keyword(s):  
High Voltage ◽  
Cross Sectional Area ◽  
Power Cable ◽  
Power Cables ◽  
Sectional Area ◽  
Cable System ◽  
Cross Sectional ◽  
The Core ◽  
The Cross ◽  
The Cost

The ampacity of high-voltage power cables depends, among others, on their core cross-sectional area as well as thermal resistivity of the thermal backfill surrounding the cables. The cross-sectional area of the power cables’ core is selected according to the expected power to be transferred via the cable system. Usually, the higher the power transfer required, the higher the cross-sectional area of the core. However, the cost of high-voltage power cables is relatively high and strictly depends on the dimensions of the core. Therefore, from the economic point of view, it is interesting to focus on the improvement of the thermal condition around the cables, by changing the dimension of the thermal backfill, instead of increasing the power cables’ core cross-sectional area. In practice, it is important to find the optimal dimensions of both cable core and thermal backfill to achieve the economically attractive solution of the power cable transfer system. This paper presents a mathematical approach to the power-cable system design, which enables selecting the cost-optimal cross-section of a power cable core depending on the dimensions of the thermal backfill. The proposal herein allows us to indicate the condition in which it is advantageous to increase the core cross-sectional area or to expand the dimension of the backfill. In this approach, the optimal backfill geometry can also be evaluated. The investment costs of the 110 kV power cable system with the core cross-sectional areas consecutively equal to 630, 800 and 1000 mm2 have been compared.

Sheath Voltages and Currents in 230kV Oil-Filled Underground Power Cables

2015 ◽  
Vol 781 ◽  
pp. 276-279 ◽  
Author(s):  
Surasak Phanthurat ◽  
Apibal Pruksanubal
Keyword(s):  
Electric Shock ◽  
Heat Losses ◽  
Power Cables ◽  
Grounding System ◽  
Three Phase ◽  
Underground Power Cables

Three-phase underground power cables can induce voltages and currents in their recover sheaths. The induced voltages and currents in sheath are undesirable. They generate heat losses and reduce the cable ampacity. Moreover, the induced voltages can generate electric shock to the workers, who maintain the power cables. It is very important to predict the sheath voltages and currents, which depend on different parameters, such as the sheath grounding system, the geometry of the cables, the gap between them, etc. In this paper, the voltages and currents induced in sheath for different installation of underground power cables (trefoil and flat formation) are studied and presented. For each case study of installation, the results of sheath voltages and currents have been computed and compared. Finally, the case of cross bonding with increasing of cable spans can reduce the sheath voltage significantly.

Energy saving in the tissue industry: technical and economic aspects of a case study

2006 ◽  
Vol 14 (2) ◽  
pp. 185-193 ◽  
Author(s):  
R. Gabbrielli ◽  
C. Medeot ◽  
D. Miconi
Keyword(s):  
Energy Saving ◽  
Economic Aspects

scholarly journals Polyethylene Nanocomposites for Power Cable Insulations

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 24 ◽  
Author(s):  
Ilona Pleşa ◽  
Petru Noţingher ◽  
Cristina Stancu ◽  
Frank Wiesbrock ◽  
Sandra Schlögl
Keyword(s):  
Electrical Performance ◽  
Power Cable ◽  
Power Cables ◽  
Structure Property ◽  
Thermoplastic Polymers ◽  
Water Tree ◽  
Tree Resistance ◽  
Structure Property Relationships ◽  
Aging Mechanisms ◽  
Comprehensive Study

This review represents a comprehensive study of nanocomposites for power cables insulations based on thermoplastic polymers such as polyethylene congeners like LDPE, HDPE and XLPE, which is complemented by original results. Particular focus lies on the structure-property relationships of nanocomposites and the materials’ design with the corresponding electrical properties. The critical factors, which contribute to the degradation or improvement of the electrical performance of such cable insulations, are discussed in detail; in particular, properties such as electrical conductivity, relative permittivity, dielectric losses, partial discharges, space charge, electrical and water tree resistance behavior and electric breakdown of such nanocomposites based on thermoplastic polymers are described and referred to the composites’ structures. This review is motivated by the fact that the development of polymer nanocomposites for power cables insulation is based on understanding more closely the aging mechanisms and the behavior of nanocomposites under operating stresses.

Troubleshooting Cable Deployed Thru Tubing Electrical Submersible Pumps: A Case Study from South East Asia

2021 ◽  
Author(s):  
Saurabh Anand ◽  
Eadie Azahar B Rosland ◽  
Elsayed Ouda Ghonim ◽  
Latief Riyanto ◽  
Khairul Azhar B Abu Bakar ◽  
...  
Keyword(s):  
Low Cost ◽  
Power Cable ◽  
Related Data ◽  
Root Cause ◽  
Artificial Lift ◽  
Electrical Submersible Pumps ◽  
Cause Of Failure ◽  
Water Cut ◽  
Discharge Pressure

Abstract PETRONAS had embarked on an ambitious thru tubing ESP journey in 2016 and had installed global first truly rig less offshore Thru Tubing ESP (TTESP) in 2017. To replicate the success of the first installation, TTESP's were installed in Field – T. However, all these three TTESP's failed to produce fluids to surface. This paper provides the complete details of the troubleshooting exercise that was done to find the cause of failure in these wells. The 3 TTESP's in Field – T were installed as per procedure and was ready to be commissioned. However, during the commissioning, it was noticed that the discharge pressure of the ESP did not build-up and the TTESP's tripped due to high temperature after 15 – 30 mins of operation. Hence none of the 3 TTESP's could be successfully commissioned. Considering the strategic importance of TTESP's in PETRONAS's artificial lift plans, detailed troubleshooting exercise was done to find the root cause of failure to produce in these three wells. This troubleshooting exercise included diesel bull heading which gave some key pump performance related data. The three TTESP's installed in Field – T were of size 2.72" and had the potential to produce an average 1500 BLPD at 80% water cut. The TTESP deployment was fully rigless and was installed using 0.8" ESP power cable. The ESP and the cable was hung-off from the surface using a hanger – spool system. The entire system is complex, and the installation procedure needs to be proper to ensure a successful installation. The vast amount of data gathered during the commissioning and troubleshooting exercise was used for determining the failure reason and included preparation of static and dynamic well ESP model. After detailed technical investigative work, the team believes to have found the root cause of the issue which explains the data obtained during commission and troubleshooting phase. The detailed troubleshooting workflow and actual data obtained will be presented in this paper. A comprehensive list of lessons learnt will also be presented which includes very important aspects that needs to be considered during the design and installation of TTESP. The remedial plan is finalized and will be executed during next available weather window. The key benefit of a TTESP installation is its low cost which is 20% – 30% of a rig-based ESP workover in offshore. Hence it is expected that TTESP installations will pick-up globally and it's important for any operator to fully understand the TTESP systems and the potential pain points. PETRONAS has been a pioneer in TTESP field, and this paper will provide details on the learning curve during the TTESP journey.

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