Autonomous Rim Drive Heliostat AutoR
TRINAMIC’s strong support for renewable energy has led to cooperation with the German Aerospace Agency—known by the German language initials DLR—and the University of Hamburg’s Department of Telematics on a unique heliostat design. Trinamic is designing ultra-efficient smart drives and control system for a new type of heliostat, the RIM DRIVE HELIOSTAT. Heliostats comprise thousands of individual mirrors that track the sun’s movement to reflect energy to a common steam turbine for electricity generation. Each mirror requires a motor to control the sun-tracking movement, and all motors must be centrally controlled.
Andreas Pfahl, from DLR, inventor of this new heliostat concept, developed the basic idea for the RIM DRIVE HELIOSTAT as he wondered why drives of conventional heliostats are placed near the rotational axes. This placement leads to high resistance and demands high precision of the heliostat motor drives.
“Imagine positioning the door knob close to the hinge instead of placing it (as normal) at the other edge, where the door is easier to control.”
By positioning the drives near the heliostat rims, it is possible to significantly increase the leverage and reduce the load and the required drive precision. Using a ray-tracing program provided by DLR, it was possible to prove that this kind of heliostat is suitable for all possible positions within a heliostat field.
With a special drive system designed by Trinamic, the usual self-locking gears (which are inefficient and expensive) can be avoided. Thus the efficiency of the heliostat is increased by a factor of two, which reduces the cost of energy supply and storage of the autonomous heliostat significantly. With a meshed wireless network, cabling can also be avoided completely. The autonomous rim drive heliostat is being developed in the project “AutoR” together with the German Space Agency DLR and the Technical University of Hamburg Harburg Department of Telematics.