Search

Wide band-gap (WBG) semiconductors technology represents a potential candidate to displace conventional silicon (Si) technology used in power electronics. Between Silicon Carbide (SiC) and Gallium Nitride (GaN) power semiconductors, the latter is the least mature of both technologies, with many open research problems, especially in the aerospace industry. In this paper, we address the design and implementation of a DC/DC converter for a hybrid small unmanned aerial vehicle (UAV) based on GaN technology. Both theoretical and simulation comparisons of Si, SiC and GaN transistors for the converter are presented. The conclusion is that GaN devices are the most appropriate to ful ll converter requirements for the size and weight limitations of the selected UAV. The paper presents a buck converter which handles an input voltage range of 32 V to 40 V and provides a 12 V regulated output and output power up to 60 W. The experimental results carried out on the prototype converter show how promising the GaN technology is for aerospace systems, not only regarding its volume and size, but also its ef ciency. Besides, practical implementation details are reported to contribute to the design of small, light and reliable GaN power converters for aeronautics. Ministerio de Ciencia, Innovación y Universidades RTI2018-101519-A-I00

Emergency locator transmitters (ELTs) used to locate manned aircrafts are not well suited to find and recover small crashed unmanned aerial vehicles (UAVs). ELTs utilize an international satellite system for search and rescue (Cospas-Sarsat System), which should leverage its expensive resources to save lives as a priority. Besides, ELTs are too big and heavy to be used within small UAVs. Some of the existing solutions for this problem are based on receivers that detect signal strength, which may be a long and tedious process not suitable for user needs. Others do not have enough range or require radio license and expensive amateur radio receivers. This paper presents an emergency radio beacon specifically designed to locate small UAVs. It is triggered automatically in the event of a crash and allows finding and recovering a crashed UAV in a fast and simple way. It meets not only the required specifications of user-friendliness, size and weight of this kind of application, but also it is a high precision and low cost device. Besides, it has enough range and endurance. The experiments carried out show the operation of the proposed system.