Electric power industry consulting
We have to design the cable length that the customer wants. However, let’s discuss which line length would be particularly inconvenient for us and why. The answer to this question depends on the voltage class and the method of neutral grounding. Today, let’s only discuss 110-500 kV networks with a grounded neutral. For such networks,
There are projects where reserve cables or reserve pipes/ducts are provided (empty or with a cable in them). Of course, this complicates the project and makes it more expensive, but maybe it’s worth it? It looks like we are talking about “insuring” a cable line in case of trouble, but the problem is that even
Our industry has excellent international standards (IEC) and excellent software. Both provide us with high accuracy calculations. However, despite the precise methods, can we be sure of the results of the calculations? Of course not! At least because we don’t always understand which source data to use in calculations. If we do not have accurate
In the energy industry, many processes can not only be calculated on models, but also measured in an operating network. Measurements are important because they allow us to verify the models and, if necessary, adjust them. One of the areas where measurements in the network are practically impossible is impulse processes (lightning and switching). Therefore,
Sooner or later, we will make a series of posts about wave processes in cable lines. Understanding these processes allows, for example, to solve the following tasks:1️⃣ Determine the core current when the cable is energized.2️⃣ Determine, for cable lines with single-side grounding of the screens, on which of the two sides it is better
We all know that to build an extended cable line, we have to replace HVAC technology with HVDC technology. However, where does one get the value of the length of the line, after which the transition to HVDC can no longer be avoided? It turns out that this length can be determined by calculation, and
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
The screen (and core) must withstand the short-circuit (fault) current (If), taking into account its time (tf). For XLPE- and EPR-insulated cables, the temperature during a short-circuit should not exceed 250°C. In the lack of information, this temperature is applicable for both the core and the screen. However, according to IEC 61443, if the screen
Modern MV-HV cable has conductive screen. Such screen, after grounding, make it possible to equalize the electric field in the cable insulation and eliminate this field outside the cable. In practice, the question arises – how to choose the screen cross-section? Cable factories have their own opinion. Let’s assume that a screen is made out
Numerous cable lines running next to each other are usually assembled together into so-called pipe blocks. For example, this happens in areas near the switchgear, where up to several dozen parallel lines can be located in one place. Usually, the number of pipes exceeds the number of cables that need to be laid. Such a