A simplistic explanation of the tradeoff between HVAC and HVDC transmission with modern technology is that HVDC has lower losses, but the converter and switchin

A simplistic explanation of the tradeoff between HVAC and HVDC transmission with modern technology is that HVDC has lower losses, but the converter and switching stations are more expensive. So HVDC can make sense for an application that needs to transmit a very large amount of power over a huge distance with no need for switching stations midway. A classic example would be linking a very large offshore wind farm to the onshore transmission system. But for "normal" transmission applications, where there are many stations connecting different HV circuits to each other as well as to lower voltage distribution circuits, it is less economical.