On-board electrical systems are the key components of each modern aircraft. They enable its safer, more comfortable, and environmentally friendlier operation. The strict regulations to reduce pollution and noise are produced by aircraft eventuated in projects like Clean Sky or ICAO Global Coalition for Sustainable Aviation. One solution to environmentally friendlier operation is the full electric propulsion of the aircraft, which enables the reduction of both noise and pollution. Such a concept requires a total change of all on-board power systems and enables the profound change in aircraft design. This paper presents the evolution of aircraft power systems into the so-called more electric aircraft (MEA) and discusses the state-of-the-art electrical systems. Furthermore, the concept of all-electric aircraft (AEA) is presented here.

Nowadays, electric propulsion system implementation in vehicles is popular, and many studies and prototypes have been accomplished in this field. Aircraft are important members of the vehicle family, and Unmanned Aerial Vehicles (UAVs) are part of this family as well. Some UAVs still have conventional propulsion systems, which are less efficient and are harmful to the environment. In addition, conventional systems are vulnerable to faults in their propulsion system components. To overcome these problems, we designed a multi-phase Brushless Direct Current (BLDC) motor, to achieve fault-tolerant operation. Our designed BLDC motor was implemented in a UAV model that was created on MATLAB Simulink, based on a currently used UAV. Our design and performance analysis are shown for the BLDC motor, both standalone and as implemented in the created UAV model. The electric propulsion system performance is shown, according to the determined flight profile. We observed that the designed electric machine is capable of producing the required torque to create thrust for lifting the UAV. There are some advantages and disadvantages to using the designed electric machine in this class of UAV. This is shown in the related sections.

Unmanned Aerial Vehicles (UAVs) are increasingly used in both civilian and military applications around the world. There are several types of UAVs with classifications according to several quantities. Medium-Altitude Long-Endurance (MALE) UAVs comprise one of these classifications. Hybrid or electric propulsion systems are another topic that is becoming popular. Implementing electric propulsion systems in vehicles could result in more efficient, environmentally friendly, and improved systems in comparison with conventional systems. This concept can be seen in the automotive sector, and today, it is popular in the aviation sector. Based on a literature review, full-electric concepts are often applied to some classes of UAVs. MALE-class UAVs are often used with conventional propulsion systems, as they need a long endurance during flight. It is known that current battery technologies and weight limitations on board do not allow as long of a flight time as conventional systems. Even knowing this, there could be some advantages to choosing an electric propulsion system in MALE-class UAVs. The effects and performance of electric propulsion in MALE-class UAVs were studied with a newly designed electric machine and a newly created UAV model.