A scaling method for a multi-terminal DC experimental test rig

This paper demonstrates a scaling method for an experimental test rig to represent the steady state operation of different HVDC transmission systems. The method is based on a parameter conversion between the experimental rig and the HVDC system under study. A virtual resistance is added to the DC cable resistance of the experimental test rig in order to achieve the same steady state operation as the real HVDC system. A droop control correction in the VSCs was used to implement the virtual resistance. A Hardware-in-the-loop set-up formed by laboratory-scale power electronic devices and a Real Time Simulator was used to test this scaling method. Three case studies modelled in PSCAD/EMTDC were used to verify that the results show good agreement.