High voltage direct current (HVDC) transmission technology is a practical and effective option to limiting short circuit currents. HVDC is one of the key solutions to transmit bulk power over large distances
[4], gradually becoming a critical technology in the field of power grid planning [5]. HVDC transmission system has three aspects of advantages
1) Since the power flow through HVDC can be controlled independently and rapidly, compared with pure AC power systems, the power grid with HVDC is able to be stabilized against larger disturbances.
2) HVDC allows connected power systems running at different frequencies, which improves the economy of each grid by optimizing power exchange.