Cable lines / 23.06.2024

Link boxes for cable screen cross-bonding

Screen cross-bonding is an important element of many 6-500 kV cable lines built with single-core XLPE-insulated cables. Therefore, special attention should be paid to the design of the cross-bonding nodes, the specifics of their installation and operation. The screens of the main 6-500 kV high-voltage cable are removed from the cable joint using special 3-6

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Cable lines / 18.06.2024

High Voltage Cable Lines

The distribution of the book “High Voltage Cable Lines” (dated 2024) has begun: This electronic book, dated 2024, explores the design, construction and operation of alternating current cable lines rated from 6 to 500 kV, consisting of single-core or three-core cables with XLPE insulation. It is intended for employees of design organizations and power grid companies,

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Cable lines / 24.05.2024

Ribs along the cable outer sheath

There are dozens of cable manufacturers in the World. They are constantly experimenting, trying to offer the market improved cable designs. Some of these innovations are not entirely successful. Unfortunately, these experiments are paid by grid companies, which get troubles during the proccess of laying cables, their operation and repair work. In my opinion, one

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Cable lines / 21.05.2024

Transition tower is always a reason to talk

Sometimes I envy overhead line (OHL) specialists because it’s always easy for them to show what they are doing. They walk down the street with family and friends and say – look, there is a tower (pylon, pole), there are wires hanging, and shield wires above them, and birds that have built nests. But what

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Cable lines / 25.04.2024

Sheath Voltage Limiters (SVL) and their damages

Single-core cables with XLPE insulation are massively used in 110-500 kV networks. Solid (two-sided) grounding of the screens of such cables leads to negative consequences, and therefore, as a rule, for screens should be used:✅Single-point grounding (see diagram)✅Cross-bonding. In both schemes, voltages may occur on screens relative to the ground caused by interference from the

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Cable lines in ducts / 11.04.2024

Cable ducts can hide issues

All over the world, more and more cable lines are laid not in the ground, but in ducts (conduits, pipes). Such ducts are made of various materials (PE, HDPE, PE-RT, PP, PVC), they can be single-layer or multi-layer. But all these ducts have one common problem – they have “infinite” impedance Rd of the side

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Cable lines in ducts / 28.03.2024

Long vertical cable pipe = good heater

Cable terminations are a weak element of the cable line, since:✅they have a complex structure;✅they are mounted manually (and the quality of installation depends on the qualification of the installer and his mood);✅they are subject to various external influences (sun, wind, rain, snow, ice etc). When a cable termination is damaged, it is not always

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Cable lines / 18.03.2024

Cable capacitance is able to surprise

The electrical capacitance of cables directly affects the arrangement of medium-voltage 6-35 kV networks with an isolated neutral, as well as issues of reactive power compensation of 110-500 kV networks. Let’s talk about what kind of capacitance the modern cables have. THE FIRST.When cables with cross-linked polyethylene (XLPE) insulation appeared, we were told that these

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Cable lines / 07.03.2024

Two types of screen cross-bonding

In 6-500 kV networks, single-core cables with XLPE insulation are widely used. Such cables have conductive screens. In such screens, if they are grounded at both ends, AC 50 Hz currents are induced in normal mode and active power losses occur. This leads to additional heating of the XLPE, a decrease in the long-term permissible

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Cable lines / 29.02.2024

The perfect grounding of the screen may be bad

The reliability of cable lines is catastrophically dependent on the quality of installation work. Therefore, we can only be glad that there are a large number of experts all over the world who do their job accurately and precisely. Certainly, some of them may even be called as perfectionists. However, in my opinion, there is

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