A Review of Critical Technologies for Making a More Electric Engine

The requirements for improvement of the efficiency, reliability, and environmental safety, as well as for reducing the weight and size for aircraft devices and systems, are decisive in choosing the direction of development of the aviation industry. The development of the concept of more electric aircraft and the concept of an more electric engine, which involves replacing hydraulic and pneumatic systems by electric equivalents, is gaining ever more popularity. Both individual research groups and global aircraft engineering and aviation corporations are paying attention to the development of these promising technologies. The concept of more electric aircraft is widely covered in the scientific and technical literature, whereas the concept of an more electric engine included therein has not received such attention. This paper presents an overview of publications devoted to the use of electric machines for the more electric engine. The paper is focused on electric machines embedding into aircraft engine shafts (embedded starter-generators for a high-pressure shaft cascade and embed electric generators for a low-pressure shaft cascade, and electric drives of fuel-and-oil systems, as well as the use of electric machines in air conditioning systems onboard an aircraft).