A novel operation method for meshed HVDC overlay grids and corresponding steady state and dynamic power flow calculation principle

Up to date numerous HVDC projects have been realized all over the world. But all of them are point to point transmission lines or non meshed multi terminal HVDC systems. To guarantee redundancy and hence security of supply and system stability, a meshed HVDC grid (MTDC) is necessary and also intended i.e. for Europe. Since there is no realized MTDC project the network calculation and operation also in interaction with the ac grid are subjects of research. This paper presents a novel method for steady state and dynamic load flow calculation as well as a method for automatic participation of a MTDC grid in load frequency control caused load flows and a decentralized DC voltage control.