Multiterminal high-voltage direct current (MTDC) systems are anticipated to enable the massive integration of renewable energies into modern grids. However

the protection of MTDC systems is a major challenge for their application in connection with offshore wind farms (OWF). This is due to the extremely high short circuit currents

present for very short timeframes

and characterised by the absence of zero-crossing currents. Additionally

economic and technological issues further challenge widespread implementation of MTDC systems. The main constraints of MTDC protection coordination systems are generally associated with fault detection

DC reactor (DCR)

DC circuit breaker (DCCB) operation time

and converter blocking time. This paper presents strategies for achieving full-selectivity (F-S) and partial-selectivity (P-S) in the protection of voltage source converter (VSC)-MTDC systems. A case study is setup to design both the F-S and P-S protection schemes. Initially

suitable DCRs are calculated for the case study

followed by selecting DCCB operation times with offshore converter blocking for both cases. Finally

an inverse time-current curve is proposed for different scenarios

considering sensitivity to DCR ratings to enhance converter blocking performance. The case study is conducted in PSCAD/EMTDC software and the simulation results demonstrate the impact of the different scenarios on the MTDC systems.