HVDC have following advantages :
1. Improved stability.
2. Fast control of power flow.
3. Only two conductor is required.
4. If we use ground as return then only one conductor is required.
5. Corona loss is proportional to frequency and frequency of DC is zero hence less corona loss in HVDC.
6. Charging current is not present in HVDC hence economical power transfer for longer distances .
7. Low diameter size conductor can be use because skin effect is absent in HVDC .
These are some advantages of HVDC.