Summary
HVAC cable lines play a key role in the energy system. Despite the fact that cross-bonding of the screens of single-core cables is considered in a number of documents, some issues still need to be clarified there. The purpose of the article is to show the need to use statistical methods for calculating lightning processes in the cross-bonding nodes, to share operational experience that suggests the need for broader consideration of switching processes, and to propose a new rule for selecting operating voltage of sheath voltage limiters (SVL).
Read more Read lessThe standard requirement to lay bonding cables as close to each other as possible was confirmed using statistical calculations. For this reason, it is necessary to minimize the use of cable joints (and link boxes) in which the inputs of the screens are made in opposite directions.
Statistical calculations also confirmed that the length of bonding cables can safely exceed 1015 m. These values are deemed to be limiting in regulatory documents.
The article calculates the switching processes on one of the lines, and shows why there are risks of damage to the joints located closest to the circuit breaker supplying voltage to the line.
The results of such calculations are confirmed by the operating experience of a number of cable lines, where numerous damages to such joints were recorded.
The article also shows what difficulties personnel have if cross-bonding nodes are equipped with SVLs having a standard operating voltage, which is usually about 3-6 kV. Article suggests slightly increasing the operating voltage of the SVL and explains why this is beneficial.
Additional informations
| Publication type | Session Materials |
|---|---|
| Reference | B1_12377_2026 |
| Publication year | |
| Publisher | CIGRE |
| Country | Portugal |
| Study committees | |
| File size | 932 KB |
| Price for non member | 30 € |
| Price for member | 30 € |
Authors
FERREIRA César - CABELTE; REBELO Patrícia - CABELTE; DMITRIEV Mikhail - CABELTE
