Voltage stability assessment in semi-autonomous DC-grids with multiple power modules

Basic concepts with respect to stable operation of semi-autonomous low-voltage DC-grids are discussed. Design considerations on the output impedances of power electronic converters are analysed in order to avoid resonance issues within a DC-grid. With calculated or measured converter output impedances, potential resonance problems due to background harmonics between aggregated power modules and the DC-grid can be forecasted. Simulation results are included for verification of the proposed ideas.