Dynamic behaviour of multi-terminal VSC-based HVDC after a converter outage: DC control strategy

The aim of this paper is to evaluate the effect of DC-voltage control strategy on dynamic behaviour of multi-terminal Voltage-Source Converter (VSC)-Based HVDC after a converter outage. In this paper, two dc voltage control strategies are considered: (i) standard voltage margin method (SVMM) and (ii) standard voltage-droop method (SVDM). The impact is evaluated in this paper using time-domain simulations on simple test system using DIgSILENT PowerFactory considering a sudden disconnection of a converter-station. Simulation results demonstrate how important is the dc-voltage control strategy and the location/number of dc-buses involved in the dc-voltage on the dynamic response of the MTDC systems. The voltage margin control is capable to survive a converter outage just if this converter is operating on constant power mode