Development of a Turbo Electric Distribution System for Remotely Piloted Aircraft Systems

Design Factors of High- speed Turbo-electric Distributed Propulsion System

“…Next, the voltage output is selected, which should be specific for the operation. In the case of Remotely Piloted Aircraft Systems (RPAS), a 12S LiPo (Lithium Polymer) powered propeller motor gives the desired voltage output of 44 V. Since the power needed for the aircraft is under 2 kW, the sleeve material is changed to a more common Inconel 718, as shown in Table 7 [17]. The graphs show that the number of turns should be lower so the output could be set at 1.…”

“…To achieve the desired voltage and power output, the stator length can be increased, while reducing the sleeve thickness and air gap. Based on these conditions, three machines of similar power output are analyzed in Ansys Maxwell [17]. The resulting data are summarized in the following tables.…”

“…A typical gas turbine engine shaft rotates at extreme speeds, e.g., a turboshaft used in a conventional aircraft typically rotates up to 40,000 rpm, and a micro gas turbine up to 600,000 rpm [18,19]. Whereas, the aircraft propeller requires a much lower rotational speed, typically under 10,000 rpm to operate at optimum efficiency and below the speed of sound [17,20]. Higher propeller speed increases the tip speed and creates shock waves that result in high structural loads while reducing efficiency [21,22].…”

“…The application of TeDP power generation requires low weight and high-speed operation. The PM machines have low weight and are typically designed to operate in high-speed conditions, which makes them the most suitable option for application in TeDP [17,25,30,31].…”

“…Considering such factors as high-power density, lower weight, compactness, simple structure, high efficiency, and being able to be used as a starter motor, the Permanent Magnet Synchronous Machine (PMSM) is the optimum choice for aerospace applications. Its other advantages include inherent PM excitation, less complicated designs requiring fewer support systems, improved power electronics, and the use of the stator structure [17,38,39]. It also generates less heat, since the externally coupled spool provides enough cooling from the flowing wind.…”