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 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 Analisis Perbandingan Efisiensi Penyaluran Listrik Antara Penghantar ACSR dan ACCC pada Sistem Transmisi 150kV

2019 ◽  
Vol 11 (1) ◽  
pp. 37-45
Author(s):  
Oktaria Handayani ◽  
Tasdik Darmana ◽  
Christine Widyastuti
Keyword(s):  
Power Plant ◽  
High Voltage ◽  
Transmission Lines ◽  
Power Losses ◽  
Long Distance ◽  
Calculation Results ◽  
Rate Of Recovery ◽  
Extra High Voltage ◽  
Load Center

Electricity need in Indonesia continues to increase in accordance with the rate of recovery of the economy and industry and the increase in population. The transmission line transmits electricity from the power plant to the load center via the High Voltage transmission lines (SUTT) or Extra High Voltage Transmissio lines (SUTET), because the long distance causes power losses. The condition before the reconducting of Tebing Tinggi - Kuala Tanjung transmission uses ACSR conductor types and after the reconducting has been replaced by the ACCC, where ACCC has 2 times the current trying of the type of ACSR. In this study, we will examine and analyze the magnitude of the power losses and the efficiency of the distribution of the two types of ACSR and ACCC supply channels with a case study of the 150 kV transmission system Tebing Tinggi - Kuala Tanjung which has a distance of 71.5 km. From the calculation results obtained, after the reconducting process using the conductor the ACCC was able to reduce power losses and increase efficiency by 1.35%.    

scholarly journals Denoising of Heavily Contaminated Partial Discharge signals in High-Voltage Cables Using Maximal Overlap Discrete Wavelet Transform

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6540
Author(s):  
Mohammed A. Shams ◽  
Hussein I. Anis ◽  
Mohammed El-Shahat
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
High Voltage ◽  
Signal To Noise Ratio ◽  
Partial Discharge ◽  
Gaussian White Noise ◽  
Discrete Wavelet ◽  
Power Cable ◽  
Power Cables ◽  
Algorithm Performance

Online detection of partial discharges (PD) is imperative for condition monitoring of high voltage equipment as well as power cables. However, heavily contaminated sites often burden the signals with various types of noise that can be challenging to remove (denoise). This paper proposes an algorithm based on the maximal overlap discrete wavelet transform (MODWT) to denoise PD signals originating from defects in power cables contaminated with various levels of noises. The three most common noise types, namely, Gaussian white noise (GWN), discrete spectral interference (DSI), and stochastic pulse shaped interference (SPI) are considered. The algorithm is applied to an experimentally acquired void-produced partial discharge in a power cable. The MODWT-based algorithm achieved a good improvement in the signal-to-noise ratio (SNR) and in the normalized correlation coefficient (NCC) for the three types of noises. The MODWT-based algorithm performance was also compared to that of the empirical Bayesian wavelet transform (EBWT) algorithm, in which the former showed superior results in denoising SPI and DSI, as well as comparable results in denoising GWN. Finally, the algorithm performance was tested on a PD signal contaminated with the three type of noises simultaneously in which the results were also superior.

scholarly journals Thermal Effect of Single Loop Shield on High-Voltage Cable Line Capacity

2021 ◽  
Author(s):  
Oleksandr Tkachenko ◽  
◽  
Vladimir Grinchenko ◽  
Pavel Dobrodeyev ◽  
◽  
...  
Keyword(s):  
Thermal Effect ◽  
High Voltage ◽  
Thermal Field ◽  
Magnetic Coupling ◽  
Maximum Temperature ◽  
Thermal Resistivity ◽  
Power Cables ◽  
Cable Line ◽  
Single Loop ◽  
Short Section

The paper deals with a single-loop shield with an asymmetric magnetic coupling used for a magnetic field mitigation of a high-voltage three-phase cable line. The goal is to evaluate a thermal effect of this shield on a cable line capacity. To calculate the flat cable line capacity in the nonshielded case, we use a standard IEC 60287. To achieve the goal we carry out a numerical simulation of the thermal field when the shield is installed. Wherein, we deal with two specific sections. One is a long section with the shield being distant from the cable line. The other is a relatively short section where the shield is located near the power cables. The thermal field is applied for a long section in a two-dimensional formulation, and a three-dimensional formulation is used for the short section. Hence, we have obtained the dependences of the maximum temperature of the power cables on parameters of the shield and its location height above the cable line. The most significant allowable cross-sections of the shield cable and their location height have been determined, when the thermal effect of the shield does not decrease the cable line capacity. These results have ensured the maximum cable line capacity while shielding. The shield temperature is shown to exceed the allowable level in the short section. To reduce it the thermal backfill has been used. We recommend the values of its thermal resistivity to be used for different parameters of the single-loop shield.

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.

Analysis and calculation the thermal stress and short circuit force of the power cable line

2014 ◽  
Author(s):  
Zhen-peng Zhang ◽  
Nai-qiu Shu ◽  
Jian-kang Zhao ◽  
Wen-bin Rao ◽  
Shao-xin Meng ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Short Circuit ◽  
Power Cable ◽  
Cable Line

Finite Element Analysis on the Overload and Short Circuit Ampacities of Kevlar Armored Subsea Power Cable

2017 ◽  
Vol 51 (3) ◽  
pp. 36-42
Author(s):  
Narayanaswamy Vedachalam ◽  
Arunachalam Umapathy ◽  
Gidugu Ananda Ramadass
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Short Circuit ◽  
Power Cable ◽  
Water Medium ◽  
Power Cables ◽  
Correction Factors ◽  
Element Analysis ◽  
Industry Standard ◽  
Continuous Current

AbstractThis paper presents the finite element electrothermal analysis done on an industry standard Kevlar armored subsea power cable to determine the cable overload and short circuit ampacities up to 256 times the continuous current rating. It is identified that the subsea cable could withstand 1.5 times and 256 times the rated current for a period of 17 min and 4.8 ms, respectively. The ampacity correction factors for operation in the water medium for a range of temperature and water flow velocities are also identified. The results presented in the form of equations shall serve as a guideline for determining the overload and short circuit protection settings of subsea power cables of similar construction.

Optimization the Arrangement of Power Cable Lines in Tunnel

2014 ◽  
Vol 678 ◽  
pp. 513-517
Author(s):  
Guang Hua He ◽  
Zhen Peng Zhang ◽  
Min Sheng Xie ◽  
Ying Xiong Wu ◽  
Dong Xing Yang ◽  
...  
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Layout Design ◽  
Power Cable ◽  
Cable Line ◽  
Force Peak ◽  
Cable Lines ◽  
Better Than ◽  
Peak Value

In order to optimized the power cable layout design in tunnel, and improved the operation ability of the cable line, this paper analyzed the cable rating and the short-circuit force under different arrangements. 220kV cable circuit was simulated in the tunnel with conditions of the flat and the trefoil arrangements. The temperature and the rating of the 220kV cable under the condition of the two arrangements were calculated in this paper. The short circuit force peak value and its direction of the cable line under short circuit current of 50kA under the condition of the two arrangements were simulated in this paper. The results show that, the cable rating in flat arrangement is better than in trefoil formation. The value and the direction of the short circuit force in tunnel are better in flat arrangement than in trefoil formation. So it is suggested that the flat arrangement is preferred when conditions permit.

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.

Sign in / Sign up

Export Citation Format

Share Document