Controlling and monitoring solar cells, lithium polymer batteries, maximum power point trackers and a high-efficiency permanent magnet motor were among the challenges facing competitors in a race for completely solar-powered race boats. Software from National Instruments played a prominent part in the solution
A race for custom-built, fully solar-powered boats travelling through 11 cities near the northern coast of The Netherlands, the Frisian Solar Challenge requires competitors to build a fast boat powered by green energy.
Competing for six days over the 220km course, teams must demonstrate design and technical innovation and successfully navigate difficult waterways and terrain to win the competition.
Competing in the class A event with single-pilot boats, the ROC Friese Poort Solar Team Sneek consists of eight university students — four mechanical engineers and four electrical engineers. While the mechanical team works on the development of the screw, propulsion, and steering, the electrical team implements the motor control, communication and measurement systems.
Five solar cells are used to power the 6m long boat, which has a top speed of 24kph. A CompactRIO system, programmed with the LabVIEW Real-Time and LabVIEW FPGA modules, is mounted inside the boat. CompactRIO provides a unique combination of I/O variety as well as control and processing capabilities in a small, power-efficient system — this is crucial for the application because space is limited on the boat and it is important to keep weight to the minimum.
More power, more speed
With CompactRIO, the team monitors the power and output of the solar cells and lithium polymer batteries. The team also uses CompactRIO to control a high-efficiency, permanent magnet motor that propels the boat as well as to control the efficient MPPT DC-to-DC converters that change the power from the solar cells to an optimised level for the electric motor. This further aids in overall efficiency and power production, which increases the speed of the boat.
CompactRIO quickly calculates and responds to changes in the optimisation point, so ensuring that the converter always maximises the power output from the solar cells. Finally, all the data is sent to a car onshore via the CompactRIO GSM and GPS Mobile modules created by National Instruments Alliance Partner S.E.A. Datentechnik GmbH.