Real-Time Simulation of an HVDC Link in Dynamic State Following AC Fault

Abstract

A 12-pulse HVDC (High Voltage direct current) system is modelled and studied in this paper based on real time simulation using RT-lab platform Hypersim OP-5600. AC fault represent the most common unsymmetrical fault in the power systems. Therefore, understanding the HVDC system fault behavior is very important for modelling, design and validation of the control system. The HVDC inverter is connected to a weak AC system and a single phase to ground AC fault is applied to the inverter bus in the goal to test the influence of the DC control on the recovery from commutation failure in front of two different values of time rising of the mechanism addressed to maintain stability, to ensure a good recovery from the fault and also inhibiting the commutation failures at the HVDC inverter valves. The results are validated by mean of digital Real time simulator HYPERSIM (OP-5600) using the Simulation In the Loop SIL approach. The performance of the HVDC system is investigated and shows the DC control influence to maintain a good and a safe stability of the system during and after the perturbation.