Up to 2 kw power transfer system for tether powered unmanned aerial vehicles to provide long flight time

Over the past decades, applications of small unmanned aerial vehicles have much increased. But there are some limitations with using small UAVs. Flight time of multirotor UAVs is one of them. This thesis is about that increasing flight time capabilities of multirotor UAVs for the case that low mobility and long hovering performance is expected. Tethered multirotor unmanned aerial vehicles can perform vertical takeoff and landing, hovering at desired altitude and position, moving as much as tether cable allows. There are no flight time restrictions that the battery powered drones has, the vehicle is tethered and get the required energy via attached cable from ground station, since meet the needs of long time surveillance of civilian and military operations. This thesis mainly focuses on the design of power transfer system including air power unit and ground power unit. DC-AC power converter methods are compared and selected most efficient one. Most of military and industrial drones are capable of lifting at least 2 kilograms. As this criterion has been considered weight of air power unit and tether cable remain within this limit. Amount of energy will be transferred from ground to the drone is the key factor for safely operation. Due to using high power brushless dc motors in military and industrial drones power demand can be higher from hobby drones. For this reason, designed power transfer system in the scope of this thesis support up to 2 kilowatts. Consequently, such a 2 kilowatts power transfer system for tethered drone become a good solution for many applications.