Flexible Automatic Generation Control system for embedded HVDC links

Future power systems are expected being operated under increasingly stressed conditions and increased uncertainties. The future single European electricity market will entail higher energy trading volumes, for which augmented use of HVDCs is expected to facilitate cross-border bulk power transfers. In traditional power systems a change in demand at one point of network is reflected throughout the system by a change in frequency. However, significant interconnections using HVDC will affect the classical ability of traditional AC system to overcome “together” frequency deviations which may result in a cascading failure and system collapse. Future HVDC systems shall fulfil requirements referring to frequency stability and also intervening in the frequency quality. As consequence HVDC systems will operate providing ancillary service depends on the framework of service. This paper proposes a flexible Automatic Generation Control (AGC) system for embedded HVDC links in order to provide frequency sensitive response and control power interchange.