Cable lines / 17.03.2025

Cable screen currents

If I hadn’t paid only 100 euros in taxes, I would be a criminal. If AC 6-35 kV networks are being massively built all over the world (for example, to connect windfarms to the grid), where each cable line has tens and thousands of euros of useless power losses in screens, then this is called

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Cable lines / 12.03.2025

Cable installation errors

Cable is like a child – it’s not enough to give birth to him at the “factory”, but he must also be given to the right “school” with good “teachers”. Let’s take a closer look at the “graduation” of our cable. The photo shows the set of 110 kV cables and their terminations, and I’m

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Cable lines / 06.03.2025

Induced currents of zero sequence

Single-core cables of 6-35 kV usually have a two-side grounding of the screens (“solid bonding”). This leads to the fact that in normal operation, the magnetic field of the core induces 50 Hz currents in the screens. At a given current in the core, the induced currents in the screens depend on:✅the cross-section of the

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Cable lines / 03.03.2025

Cable preheating

Last week in LinkedIn, I came across a post where the cable was “preheated” with an open fire before laying. Workers “heated up” beautiful cable with open fire and at the same time cheerfully said, “How good that we have a cable with a non-flammable outer sheath”. I couldn’t get past such a terrible attitude

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Cable lines / 21.02.2025

Multifaceted transition pole

There are cable lines, there are overhead lines. However, there are also mixed lines consisting of both cable and overhead sections. On such mixed lines, the question arises as to how best to equip a transition point. There are a lot of issues there:➡️ where to place the set of cable terminations and of which

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Cable lines / 12.02.2025

Bonding cable length

Let us discuss the length of the bonding cable and also such a thing as the steepness of current/voltage impulses that creates voltage drop. Industry documents suppose that the voltage in the joint can be determined as a sum of residual voltage of SVL (sheath voltage limiter) and the voltage drop across the bonding cable,

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Cable lines / 06.02.2025

Bonding cable type

For high-voltage cable lines, the cross-bonding of screens is quite common. It is used not only for 110-500 kV lines, but also for 6-35 kV. The cross-bonding assumes that the six cable screens (1,2,3,4,5,6) must be removed from the three joints (A,B,C) and then connected to each other in a cross manner using a system

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Cable lines / 29.01.2025

Cable protection

When laying cable lines in the ground, there are several different ways to provide mechanical protection for cables. The following options are known:1️⃣ Covering the cable with bricks on top.2️⃣ Covering the cable with polymer tiles/covers.3️⃣ Laying cable in pipe/duct/conduit.4️⃣ Laying cable in tray/trough.5️⃣ Laying cable in concrete tunnel.Another way of protection is to lay

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Cable lines / 24.01.2025

Universal cable line

We often think that 6-35 kV medium-voltage (MV) networks are simpler than 110-500 kV high-voltage (HV) networks. Of course, this is not the case, and it is in MV networks that many serious problems are concentrated – among them, for example, the selection of the optimal method of neutral grounding as well as the selection

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Cable lines / 20.01.2025

Cable network resonance

Medium voltage 6-35 kV grid usually do not have a solid neutral grounding, and a voltage of 50 Hz may occur on the neutral. Today let’s talk about why it may happen in the cable network even in normal operation, and how this can lead to Temporary Overvoltages (TOV) and damage to equipment. One of

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