Because of increasing development of renewable energies as well as their fluctuating
supply, the power distribution networks already reaching their load limits. A crucial point is the safety margin of minimum distance to ground and the maximum current that is defined for standardized worst case weather conditions. In order to consider the actual situation, one needs to know the actual sag of all critical sections. Fraunhofer ENAS developed together with Fraunhofer IZM, Chemnitz University of Technology, partners from industry and enviaM an energy self-sufficient sensor network that allows to monitor the sag of the lines and to optimize the utilization of the power lines.
The sensor network consists of a large number of sensor nodes at intervals of a few hundred meters along a high-voltage power line. They collect the data about temperature, inclination and line current and send them to the neighboring nodes at regular time intervals. These data are passed along the chain, collected by a base station, and sent to the control station to the operator.