Electric power industry consulting
An interesting case occurred at one of the medium-voltage facilities. The 10 kV busbars were fed by a powerful 110/10 kV step-down transformer. To reduce short-circuit currents on 10 kV side, reactors were installed there between the transformer and 10 kV busbars. The transformer and reactor were connected using single-core cables (about 50 m length,
It is believed that “we cannot have a closed contour of magnetic material around an AC single-core cable”. However, in practice, there are issues with the application of such a rule. For example, would the following contours be dangerous?➡️ it does not tightly cover the cable, but has large transverse dimensions;➡️ it has a side
Cable couplings are one of the places where cable line damage often occurs. There are many different types of couplings, but most of them can be classified into one of two categories:✅ Cable terminations;✅ Cable joints. Cable terminations are placed above the ground and can be subjected to periodic inspection, which is a good thing.
Today is a short post. It is about the need for thorough control of all stages of the cable line life cycle. And especially for the project and installation. The photo shows a 110 kV cable line, for which the cross-bonding of the screens was to be made according to the project. However, the installation
Very often we see posts where designers and installers share beautiful photos of successfully completed projects. However, then, quietly, in private correspondence, the exploiting organizations share other photos and accompany them with words “What should we do with this?” or “How do we fix this”? In short, many “successful” projects turn out to be “UNsuccessful”
We know that one of the advantages of cables with solid insulation (XLPE, EPR, PVC) is that these cables have no restrictions on the height difference of the route. We can lay such cables horizontally, vertically, at an angle. Any cable arrangement is allowed, as long as the cable bending radius is not violated and
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
At the ends of the cable line, there are cable terminations. Metallic screens of cables are removed from terminations to the outside, where they are connected in accordance with selected bonding/ grounding scheme. For example, the figure shows the high voltage cable line with one-sided grounding of screens. To have this scheme, metallic screens, with
High voltage cable terminations are usually installed vertically. This allows you:✅ To ensure the absence of mechanical influences bending the termination under its own weight and the weight of the cable.✅ To ensure high-quality filling of the termination with dielectric oil (not relevant for terminations of dry-type or gas-type). However, sometimes, for various reasons, the
Earlier, I posted some photos showing that the surge arrester (SA), in case of its damage, can pose a danger to the equipment placed nearby. But what about consequences in case of damage of cable termination or cable joint? There are some examples of what we can get for 110 kV:1️⃣ cable termination mounted in