Electric power industry consulting
Figure (A) shows the thermal scheme of a cable line laid in the ground. The following designations are used: Pc, Ps – loss of active power in the core and metallic screen of the cable; Tc, Ts, Tg – temperature of the core, screen, ground; Rins, Rosh, Rg – thermal resistances of insulation, outer sheath,
Laying cables in pipes is a common way of laying high-voltage cable lines. Usually, pipes are accounted for using a correction factor K=0.9, that is, it is assumed that laying cables in pipes reduces the permissible current by 10%. For example, if the cable line in the ground had a permissible current of 1000 A,
In the cable catalogs of leading manufacturers of power cables there is a system of correction coefficients for selecting the core cross-section. According to this system, laying cables in pipes reduces the long-term permissible current (current capacity) of the cable line, and the corresponding correction factor is 0.9. I must say that this is incorrect.
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”
You know, a lot of efforts are being spent all over the world to have energy green, however, sometimes it seems to me that the “blue sky” government program would even be much more important. I mean there are a number of countries in the world where even in large cities electricity supply to consumers
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
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,
Power transmission lines usually are double-circuit. This allows you to maintain or repair a disconnected circuit while the second circuit remains in operation and provides power to consumers. For this kind of lines, questions usually arise with the safety of personnel, since the disconnected circuit is under the influence of a 50 Hz voltage induced
The photo shows cable termination of the single-core cable, which was overheated due to high currents induced in the screen and the armor. As far as you know, for single-core cables, armor can only be made of non-magnetic materials, and the photo shows aluminum allow armor that tightly covers the cable from the outside. Why
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