Even with the renewable energy sources connected now, conditions in the supply networks have fundamentally changed. And the still growing feed-in of power from photovoltaic, wind and biogas plants is making it more and more complicated to ensure stable networks with reliable voltage and frequency bands. Effects on local distribution networks are particularly severe. Within the intermeshed, usually heterogeneous structures, typically neither regulation algorithms are used nor control variables such as controllable transformers installed.
The power networks and their switchgear have not been planned or designed for the new energy flows. So the network equipment can come under great loads, which reduce its service life. Without additional sensor systems and data acquisition, these states remain largely unknown. The additional costs owing to premature replacement of equipment and reduced network usage charges can be considerable.
As fast expansion of the networks is hardly possible and would be very cost-intensive, intelligent networks offer a solution. Their expansion can be implemented selectively and at the appropriate time. Experts estimate that approximately 10 to 15% of all
SUS (secondary unit substation) would have to be incorporated into an intelligent network to achieve significant controllability.
When choosing a technologically and economically suitable telecontrol solution, the high number of objects and flexibility during integration plays a particularly important role, as well as the often restricted space conditions. SAE concepts are attractive starting points for solving these problems. Both the fast fault localisation and the possibility of isolating fault locations help to restore a safe network state.
The bay station controllers of the series5 product series make it possible to provide all the information and function for managing networks. The integration of further intelligent components makes it possible to customise measurement points, which can be incorporated into local or regional programs for network management and wide-range regulation.
The possibility of integrating short circuit and directional earth fault indicators is of interest in particular for local network stations. The units help to localise faults in the network reliably. In the case of distributed generation and the resulting bidirectional power flow, the use of units with additional direction display is recommended.
By using what are known as DSO modules (DSO = Distribution System Operator), SAE systems make safe command termination in power networks possible. Servomotors can be controlled securely with the aid of these special modules. In this manner, affected network segments can be removed rapidly from the network and the availability of intact sections can be restored quickly. The foundation stone of an intelligent network is laid.