Aggregated active distribution networks for secondary control of islanded power systems

Future distribution networks with high penetration of renewable resources and energy storage can provide ancillary services such as frequency regulation. This study proposes a secondary frequency control scheme based on aggregated active distribution networks. The proposed method is based on hierarchical coordinated control of bidirectional controlled energy storages under islanding situations. The constitution of under-generated islanding, where total initial generation is less than the total load and the over-generated island with an initial excess generation scenarios are investigated with secondary control support. Experimental results clearly demonstrates the effectiveness of the proposed aggregated control in a laboratory based testbed involving actual generators, energy storage and phasor measurement units.