Sensorless Drone Detection for In-Flight Inductive Power Transfer Using Transmitter-Side Voltage Pulses

In-flight inductive wireless power transfer technique is a solution to extend the flight duration and reduce the battery capacity and charging time for drones. Before the power transmission, the drone detection method on a transmitter side is necessary for the reduction of magnetic field emission and power loss. A sensorless receiver coil detection using transmitter-side voltage pulses has been proposed for electric vehicles (EVs). This paper proposes the sensorless receiver coil detection for drones using the same technique. The main difference between the EVs and drones is the change of the attitude of the receiver coil such as altitude, pitch angle, and roll angle. The threshold of the receiver side current during short mode can be decided based on the coupling coefficient, therefore, the attitude difference does not affect the detection accuracy. The effectiveness of the proposal is experimentally validated using a drone test bench with changes of the altitude and pitch angle.