Gulf Countries (GCC) Common Grid Network
All the Gulf countries (Bahrain, Kuwait, Oman, Qatar, and Saudi) Power Grid Networks are inter-connected to each other county by a 400kV Common Grid which is called the “GCC-Grid Network”. Please refer to the attached image for more clarity.
Except for the Saudi Grid, all the other grids are interlinked with a 400kV Network (AC), and due to the distance to Sauid being a bit longer than the other countries, the Saudi Grid is connected via the HVDC Line. At the endpoint, the DC supply is converted into 400kV (AC system).
In Sri Lankan contexts, some discussions are being going on to interconnect the Indian Grid with the Sri Lankan CEB Grid probably with a 220kV system via HVDC line. If so thyristor-based HVDC to AC converter system has to be implemented at both country ends.
For the Grid Stability concerned, 400kV System has many advantages over 220kV system voltages.
Overall, the decision to use 400kV voltage for the common grid in Gulf countries is driven by considerations of efficinecy , cpacity, cost effectiveness and compatibility with international standards