ASTROSE – POWER LINE MONITORING
ASTROSE® is a wireless sensor network for the monitoring of high and extra high voltage power lines.
The technology was developed to address power transmission shortfalls resulting from decentralized power harvesting of renewable energy supplies (windfarms, solar parks, etc.). The non-site-specific sensor system collects data, which is in turn applied to modify power line operation. In detail, sensor nodes are attached to each section of a power line. These not only measure line sag but also comprise the smallest units of a wireless data transmission that relays the measured data back to a base station. Two key technical challenges were met in realizing this system: firstly, autarkic (self-sustaining) upgradable wireless sensors that measure the data and, secondly, a CPS (cyberphysical system) infrastructure for the data communication.
The wireless sensors are at the core of the power line monitoring system. They measure the line sag, line damage, temperature and current. The inclination sensor’s required resolution is 0.01°. The operating conditions for the wireless sensors make power supply by means of harvesters mandatory. The wireless sensors include communication hardware for data transmission via the freely accessible and non-fee 2.4GHz bandwidth. Special double-slot antennas are used to ensure transmission ranges of over 1000 m. A daisy-chain or linear-type network design is used for the data transfer. This means that the first sensor node sends its measurement value back along the chain of sensor nodes. The next sensor node adds its data to that it receives and sends the total package of data on to the third sensor in the chain, and so on... until the accumulated data package reaches the so-called base station located, for example, in a substation. The data are then saved, analyzed and fed into the grid operator’s control technology.
An ASTROSE® sensor network began pilot operation in October 2014 with 59 wireless sensor nodes installed on a 110 kV overhead power line in Germany’s Harz mountain range. Over 10 million measurement values have been recorded, relayed and analyzed over 12 months of uninterrupted operation.
The next stage in the implementation of ASTROSE® is preparing testing and evaluation tools for a wide range of application areas and conditions (see PDF in the Downloads section), paving the way for broad establishment of the technology.