HVDC link earthing
HVDC link earthing
(OP)
Hello,
I would like to know what is the best way of earthing of a HVDC cable (connecting to converter stations in a monopolar mode). The way of laying is to place the screened underground power cable close to the screened return cable.
I have seen that in some cases, it was solidly earthed at both ends and in other cases the single point earthing was used.
What is in your opinion the best solution ? Advantages, disadvantages.
Total length of cable is above 30km.
Thanks for all of your help and...Merry Christmas !
Foudrette
I would like to know what is the best way of earthing of a HVDC cable (connecting to converter stations in a monopolar mode). The way of laying is to place the screened underground power cable close to the screened return cable.
I have seen that in some cases, it was solidly earthed at both ends and in other cases the single point earthing was used.
What is in your opinion the best solution ? Advantages, disadvantages.
Total length of cable is above 30km.
Thanks for all of your help and...Merry Christmas !
Foudrette






RE: HVDC link earthing
- Corrosion acceleration in pipelines and other underground metallic objects even at considerable distance is a concern for inland installation. For submarine crossing, there is a possibility to generate poison chlorine gas.
- Additional real state and O&M cost required maintaining the electrodes at each converter station.
- The system reliability of the monopolar system solely relies on the single cable availability while in bipolar designs the system could be operated in monopolar mode temporarily.
RE: HVDC link earthing
I understand that if environment is a big issue for the involved project, we need to install an underground return cable.
We plan to ground such cable systems at both ends as no induced currents are generated under DC. But, I have seen in another case that it was grounded at only one end (Swepol project). I wonder why ?
If you have any idea please let me know,
With my best wishes,
Foudrette
RE: HVDC link earthing
Grounding one end provide reference voltage and simplify the requirement for DC commutating switching devices and their duty during high-speed transfer from bipolar to monopolar operation mode.
I hope this could help to clarify your question
Marry Xmas + Prosperous 2005.
RE: HVDC link earthing
Now I see the explanation, it seems obvious to me !
But however, I was looking for an explanation for a long time, I have read many papers, but unfortunately nothing about the earthing was described.
Thanks a lot once again,
Foudrette