Multi-level secondary control for clustered power grids

Distributed generation (DG) technologies are emerging. Nevertheless, still no sufficient strategies for active grid integration of DG units and their participation in grid control are available. Including DG units into the control of the grid state variables and into secondary grid control, would enable a variety of additional features, specially supported by the decentralized character of the DG units. This paper introduces a hierarchical multi-level secondary control (SC) concept, aiming at advanced optimization and reliability of future power systems with high penetration of DG. The control concept specially supports clustering of grids and therewith increases power supply reliability.