Battery-Controlled Electrical Propulsion
Enables Long-Range, Multi-Lap Glider Flights
Conventionally, gliders are taken by a tow plane to an altitude sufficient to increase the pilot’s likelihood of finding thermals to prolong their flight time after release. Auxiliary propulsion systems have been used to extend their range and flexibility, even to take off in the first place. Combustion motors have proved unsatisfactory for this application, but an electrical system has been successful.
The glider uses Li-ion cells to provide enough power for five minutes of operation or to climb to the desired altitude. Integral to the design of this propulsion system is the inclusion of battery charging system inside the glider enabling it to make long distance multi-lap flights and be recharged at any airfield.
Featuring high efficiency and low weight, Vicor DC-DC converters are the heart of the charging system. The charging system has a front end and a power section housed in two separate cabinets mounted in the glider fuselage. The front end consists of three ENMod AC front ends while the power section uses eight Vicor Mini DC-DC converters. The power section is connected to the battery array, which is installed inside the wings. The resulting charging unit weighs only 6 kg (about 1pounds) including cabling. The unit consumes approximately 1.7 kW of mains power and requires just nine hours to fully recharge the glider’s batteries. The auto-ranging front end of the charger is compatible with voltages from 110 to 230 Vac, making it usable worldwide.