Development of Aircraft Electric Starter–Generator System Based on Active Rectification Technology

Abstract

Abstract-More-electric aircraft (MEA) has become a dominant trend for modern aircraft. On-board MEA, many functions, which are conventionally driven by pneumatic and hydraulic power, are replaced with electrical subsystems. Starting aircraft engines with an electrical motor instead of using pneumatic power from the auxiliary power unit (APU) is one of the major characteristics of future aircraft. This paper presents the development of a novel electric starter-generator system for aircraft applications. The paper describes the main achievements of the project within the key areas including electric machines, power electronic converters, thermal management and overall system control design. The developed prototype has been tested successfully and the test results are presented in this paper.

Electrical Machines and Power Electronics For Starter-Generators in More Electric Aircrafts: A Technology Review

“…However, its physical speed limit reduces the potential for higher power densities. The key specification of the AEGART S/G system is 32 000 r/min goes beyond what current WFSM technology can deliver [37]. This paper reports that there are still ongoing research in the area of WFSM S/G systems, especially in the area of excitation systems and its associated control schemes to improve WFSM functionality.…”

“…Due to a strict request for high power density in future aviation solutions, the PM machine emerges as a strong candidate for various operations in aviation. It is worth highlighting that the AEGART project reported a power density of 16 kW/kg based on high-speed PMM S/G technology with 4 kW/kg for the associated PEC [37]. In fact, it was discovered that a corresponding S/G based on SRM technology achieves approximately 1.27 kW/kg [29], i.e.…”

“…A complicated design of the whole brushless WFSM is needed to avoid mechanical failure. An upper realistic speed limit has been stated to be around 20 000 r/min [37]. However, the integrated drive generator (IDG) of the Boeing 777 aircraft (first flight 1994) rotates at 24 000 r/min [38].…”

“…Samarium-Cobalt (Sm 2 Co 17 ) can survive temperatures beyond 300 • C [51] (maybe as high as 350 • C [52]). In general, 300 • C should be considered as the worst case temperature for the PMM S/G [37]. However, it is unavoidable that high thermal stress affects the machine robustness, ageing and lifetime.…”

“…There is also a concern related to possible detachment of magnets during high-speed operation [52] , i.e., extra high strength retention methods (e.g. carbon fiber sleeve material) must be considered for inner rotors [37]. However, modern design of S/G PMMs employs an out-runner topology (successful R&D performed by Rolls Royce Electrical Norway), where the rotor core basically support the PMs at the expense of higher inertia (which needs to be minimized).…”