Control of active networks

High penetration of distributed generation is currently limited by passive operating methods of distribution networks. At distribution level, insufficient measurements are available to allow satisfactory control, so measurement is extended through the use of state estimation. Aspects that are described in this paper include optimal measurement location, the problems occurring with few measurements, and load models used for "pseudo-measurements". Two control philosophies are described. The first, applicable to smaller network segments, is a local control, working with existing control devices such as transformer automatic voltage control (AVC) relays. The second philosophy is optimal control with constraints. (4 pages)