The maintenance and inspection of the 73,000-kilometre-network poses an enormous effort. It is currently done by manned helicopters and in detail by technicians on-site. In a test-program designed to run for multiple years, unmanned aerial systems are used as well. Among others, a Germandrones Songbird has come into operation. Jens Hache, project manager at Mitnetz, says:
"Drones simplify the monitoring of the high-voltage-grid considerably. They can be deployed in rough terrain and in bad weather. Therefore they support our technicians and help them to be better protected from dangers of examining of our cables and facilities." (1, translated)
Moreover, during the preparations and flights in November 2020, some further advantages became apparent:
- Drones are generally more economical and quiter than manned helicopters
- Thus they lower costs.
- They are more eco-friendly and give local residents a rest from noise pollution.
This is especially true for the efficient VTOL.
- Therefore they increase the acceptance of this essential work.
Deploying the Songbird is specifically worthwile where longer distances are to be covered quickly and at a stetch. While multicopters can be manouverd manually to fly precisely in close proximity of the target objects, even highly specialized models can rarely cover more than 15 kilometres before they need to be recharged. This imposes many stopovers to the operators and time consuming work in areas with little or no road infrastructure. The Songbird on the other hand can cover between 50 km and 90 km in a single inspection flight, depending on the model and payload setup. This saves effort and grants the user some flexibility in choosing the take-off and landing sites. The drone itself is undemanding, however - it only needs a free space of a few metres in diameter, for example on a dirtroad or a field. And since the working speed of a fixed-wing aircraft is naturally greater than that of a copter, the task is carried out at a good pace (the cruise speed of the Songbird is 60 to 70 km/h or approx. 40 mph).
The camera of choice is either a Sony Alpha 7 or a Phase One iXM 100 with 100 megapixels. Despite the swift fly-by some 30 m above the power poles, the image material contains great detail. The operators look out for cable-damages, birds' nests and corrosion of the pylons.
At the moment additional data processing based on artificial intelligence is in preparation, to improve the efficiency of the system even more. It will further enhance the survice security through early recognition of potential damages. To increase the degree of automation, a follow-up program is already projected that includes placing droneports alongside the power lines from which the vehicles can operate autonomously. Germandrones plans to undertake preliminary tests in 2021.
Dr. Klaus Scho, CEO
Tel. + 49 (0)30 34 78 12 81