Cable lines / 01.10.2023

Surprises with “well-known” screens cross-bonding

If you are communicating with a person who puffs out his cheeks and says that he is perfectly familiar with the screens cross-bonding of single-core high voltage cables, then ask him next simple question – “What is the difference between two types of screens cross-bonding shown on schemes (a) and (b)?” There is type “123-312”

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Cable lines / 15.09.2023

Special type of sheath voltage limiters (SVL)

High voltage cables have an outer sheath. It is very important to ensure that sheath does not have serious damage. Otherwise, water may get into the cable, which in a few years will lead to a short-circuit of main XLPE-insulation. The sheath tests are performed by applying a DC of 10 kV between the cable

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Various energy topics / 01.09.2023

Safety of the private electricity storage

Previously, cars had nothing to do with electric grids. However, with the development of renewable energy sources (solar, wind, etc.), the situation began to change. We gradually started to integrate ordinary personal cars into the energy sector. A new era has begun – hybrid or even fully electric cars have appeared. Such cars, for example,

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Cable lines / 15.07.2023

Transition towers and people protection

There are a huge number of different types of transition towers between cable and overhead lines. The photo shows one of the HV types which is used on the territory of the UK. There are similar examples from around the world. As you can see, the equipment of the transition tower is surrounded by a

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Various energy topics / 01.07.2023

How many digits is enough to be fired?

We are absolutely sure of π=3.1415926535 and e=2.7182818284 – we use them in software. However, in our everyday life, we specify only 3 digits (3.14 and 2.72), and this is enough. Rarely we give 5 digits at once (3.1416 and 2.7183). If someone indicates 6 or more, we will consider it beyond reasonable. How do

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Cable lines / 01.07.2023

Cable resistance and inductance – everything is bad!

There are «well-known» formulas for calculating the active R and inductive X impedances of the cable line, given in plenty of cable catalogs and regulatory documents. These formulas are shown in the figure. Unfortunately:1️⃣ They relate exclusively to the case of positive sequence and are inapplicable for zero sequence. That’s why they marked as R1

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Cable lines / 15.06.2023

We still can’t mount cable terminations

Look at this example of installing HV cable terminations on the switchgear. In my opinion, there are several mistakes at once. 1️⃣ The lower flange of the termination must be at least 2.5 meters above the ground (this distance is determined by the height of the service personnel who raised his hand up). However, in

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