Combined simulation method for improved performance in grid integration studies including multi-terminal VSC-HVDC

This paper presents an interfacing method to combine stability-type simulations with electro-magnetic transients (EMT) calculation. The stability-type simulation is coupled with the EMT simulation by Thevenin-equivalent variable source representations, whereas the EMT-type simulator is connected to the stability-type simulation by Fourier analysis. The paper describes this procedure and elaborates on the numerical performance of this mutual coupling, which is done by studying an exemplary test case. The focus is on integrating multi-terminal VSC-HVdc schemes in stability-type simulations.