Electric power industry
Usually a cable line has one cable (one core) for each of the three phases A,B,C. However, there are cases where the number of cables per phase increases up to 6 (see photo) or even more. This may be necessary, for example, so that the line can pass the entire operating current of the supply
We hear a lot that “green transition” is impossible without cable lines. But do we know and understand cable lines that well? Unfortunately, I have to say that we do not know them very well, and so far, the cable standards and catalogues require improvement. Let me show this using the example of the longitudinal
In the energy sector, there is more and more complex computer software for calculating equipment, various network operating modes and transients. On the one hand, this is good, but on the other hand, it personally causes me some fear. I will try to clarify my thoughts. Many of the software methods give the impression of
In 6-35 kV networks, many methods of neutral grounding are known. They differ in the magnitude of the ground fault current, the magnitude of the voltage increase on two intact phases, the ability to quickly search and selectively disconnect a damaged line, and so on. Let’s discuss a different question – how does the neutral
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
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,
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
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
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
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