Control of active networks

Abstract

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.

Including active voltage level management in planning of distribution networks with distributed generation

“…The latter approach should be used in more complex networks where multiple controllable components exist and determining simple control rules is difficult. [8] Even the simplest coordinated voltage control methods can improve the utilization of an existing distribution network in case of DG interconnection substantially. For instance, if the substation voltage is controlled based on network maximum and minimum voltages instead of only the local measurement, it was possible to increase the penetration of DG by a factor of 10 in one case study [1].…”

Distribution system state estimation-A step towards smart grid

“…The disadvantage of all these methods is that they lack robustness and will not converge 28 to a unique solution in the presence of bad measurements (e.g. measurements majorly corrupted 29 by noise) [40]. …”

Active network management of voltage leading to increased generation and improved network utilisation

“…In effect this involves lowering the network voltage by as much as possible (while maintaining all parts of the network within limits) to allow maximum generation. The principles of this system have been presented previously [1][2][3] and are described briefly. The system makes a few key measurements at the generation site and the primary substation ( Figure 2) and uses state estimation to establish voltages throughout the network.…”