Generally speaking, it depends on converter technology and control (MCC, 2-level PWM, etc..) and on dc line characteristics (submarine cable, overhead line) and length.

Typical figures are between 200 and 1000 ms.

if you are asking in the operations point of view, besides the physical/design limitations, it is usually capped by the transmission system operator's operations parameters such as frequency control. The rule of thumb is 10% per minute of the total capacity. 

HI Francisco,

Thank you for your answer. I am trying to find references for that. If you have come across any reference material can you please send me.

Thanks

Dear Dr. Davut,

Thank you for your answer. If I understood your answer correctly, the power reversal operation of a VSC-HVDC system will take about 20 minutes. Am I correct?

Again I would be grateful to you if you could find me some references

Thank you

Hi, one example from Finnish network 

however you can find other examples for IFA(france-uK) or NIRE (n ireland to uk) etc.

see if this helps 

thanks