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, replaced with electrical subsystems. Starting engines an electric motor instead of using power from the auxiliary unit is one major characteristics future This paper presents development novel starter-generator system applications. describes main achievements AEGART (EU CleanSky Project) project in key areas, including...

This paper describes an analytical model to evaluate the short-circuit (SC) current resulting from interturn fault by computing self and mutual inductances under SC condition. Two different concentrated winding configurations, i.e., horizontally vertically placed conductors in slot of a fault-tolerant permanent magnet synchronous machine are considered. By associated slot-leakage air-gap fluxes, inductance both healthy faulty windings as well between them, can be determined for any position...

This paper investigates the behavior of a vector-controlled fault-tolerant permanent magnet motor drive system adopting vertically placed strip winding (VSW) which can limit interturn short-circuit (SC) fault current to its rated value regardless position in slot containing shorted turns. The drives' dynamic is simulated using per-phase equivalent circuit model, with inductances and resistances analytically calculated based on machine geometry location. A simplified thermal model also...

This paper proposes a novel solid rotor topology for an interior permanent magnet (IPM) machine, adopted in this case aircraft starter-generator design. The key challenge the design is to satisfy two operating conditions that are high torque at start and speed cruise. Conventional IPM topologies highly capable of extended field weakening found be limited due structural constraints associated with material. To adopt concept high-speed operation, it proposed constructed from semimagnetic...

This paper investigates the effect of two soft magnetic materials on a high-speed machine design, namely, 6.5% silicon steel and cobalt-iron alloy. The design parameters performance as an aircraft starter-generator is analyzed. material properties which include B-H characteristics losses are obtained at different frequencies under experiment used to predict accurately. In investigation presented in this paper, it shown that machines designed with high core flux density has lower weight than...

This paper presents an analytical methodology based on subdomain field model to calculate eddy current loss in vertical conductor windings (VCWs) of surface mounted, radial flux, permanent magnet (PM) machines considering the penetration effect. The proposed can be used with any slot-pole combination including fractional slot having VCW. Initially, solves two-dimensional problem Laplace's and Poisson's equations using separation variables technique for each subdomains: PM, airgap, opening,...

This paper investigates the influence of slot/pole (S/P) combination on inter-turn short-circuit (SC) current in fault-tolerant permanent magnet (FT-PM) machines. A 2-D sub-domain field computational model with multi-objective genetic algorithm is used for design and performance prediction considered FT-PM The electromagnetic losses machines, including iron, magnet, winding are systematically computed using analytical tools. During postprocessing stage, a 1-D analysis employed turn-turn...

This study presents a systematic on turn–turn short circuit (SC) fault and ways to manage them provide basis for comparison of the various options available. The possible methods reduce likelihood winding SC mitigation techniques related such faults are discussed. A finite‐element analysis surface‐mounted permanent magnet machine under application different during is presented. Both drive structural adaptations addressed. Amongst investigated techniques, most promising solution identified...

This paper proposes a semi-flooded cooling concept for high speed machine design. The electrical considered is an aircraft starter-generator system where power density and efficiency are crucial. In order to achieve the permanent magnet machine, direct oil strategy stator adopted. A sleeve designed separate into oil-flooded chamber oil-free rotor avoid windage loss due speed. Different materials, Carbon Fiber (CF) E-glass fiber (GF) oil-sleeve Implications of aforementioned materials on...

The paper describes the mechanical and thermal design of a high speed, power density synchronous permanent magnet machine for an aero engine starter generator system with rating 150 kW maximum speed 32,000 rpm. As both aspects have direct impact on overall performance weight reduction, critical optimisation was carried out. Intensive cooling is guaranteed by liquid oil-cooling stationary components; stator sleeve also introduced into airgap to prevent excessive windage. Thermal...

This paper investigates high-speed surface PM machine design for portable turbo-generator applications. The rotor radius is fixed to achieve certain optimal characteristics of the magnet retention mechanism. objective this and select stator. stator designs are populated by different slot/pole combinations, winding arrangements, over a range possible stack lengths. However, constrained physical diameter, length, electrical volt-ampere constraints. A large number preliminary do not satisfy...

This paper will describe a high speed motor-drive system for an aircraft starter-generator. A permanent magnet electrical machine is designed to have minimal rotor losses and novel cooling the stator. An inner stator sleeve adopted allow flooded whilst minimizing windage loss. Different slot-pole combinations are compared in view of attaining optimal combination that provides minimum satisfying electromagnetic, mechanical thermal constrains. three-level converter structure after comparative...

This paper presents a comparative design study on Permanent Magnet (PM) rotor topologies for high speed aircraft starter-generators. The application requirements associated with the starter and generator operation is highlighted. Different concepts are investigated whilst keeping both stator diameter consistent. In addition, core material, electrical magnetic constraints thermal structural limitations also kept consistent as basis comparison of different in this study. performance optimal...

In permanent magnet (PM) machines, a turn-turn short-circuit (SC) fault is the most critical to eradicate. The introduces high SC current in shorted turn, which may consequently lead secondary faults unless appropriately controlled. This paper proposes feasible conductors' placement slot of PM machine minimize such current. order current, conductor arrangement optimized using multi-objective genetic algorithm incorporating with both analytical and finite-element numerical tool. possible...

Permanent magnet machines are widely researched for application in electric traction, aero-engine starter generators and many other industrial systems that require high performance. This paper presents the procedure design a surface PM machine with consideration on volt-ampere limitations of inverter / active rectifier. The relationship between stack length number turns its influence operating range is analytically derived represented an inductance-limit plot. Regions this plot indicate...

This paper looks at a systematic investigation on split ratio to minimize the AC losses of vertically placed rectangular conductors in concentrated-wound surface mounted PM synchronous machines having fault tolerant (FT) capability. The repeated numerical design optimization is carried out Finite Element (FE) achieve required torque and FT capabilities for minimum level electromagnetic losses. In addition, influence tooth width slot pitch ratio, slotting effects height are investigated....

This paper presents an analytical model to evaluate the inter-turn short-circuit current in a Fault Tolerant Permanent Magnet Synchronous Machine (FT-PMSM) for different winding configurations. By evaluating slot-leakage and air-gap fluxes, inductance of both healthy faulty parts phase winding, as well mutual between them, can be determined any position number shorted turns. Using these inductances, is determined. The proposed verified with finite-element analysis validated experimentally....

This paper presents design optimization of a short-term duty electrical machine for extreme environments high temperature and altitudes. For such environmental conditions above 80°C altitudes 30 km, thermal loading limits are critical consideration in machines, especially if power density efficiency to be achieved. The influence different material on the performance machines is investigated. Also, effect slot pole combinations studied used operating but with short duty. In research,...

The dynamic behavior of the rotating machinery supported by hydrodynamic journal bearings is significantly influenced characteristics oil film. In present work an efficient identification method used to identify stiffness and damping coefficients tilting pad cylindrical a flexible rotor-bearing system. uses FRFs (Frequency Response Functions) obtained measurements finite element method. accuracy feasibility were tested demonstrated theoretical simulation. possible effects oil-film inertia...

The misalignment between the journal and bearing in a rotor-bearing system may be due to manufacturing error, elastic deflection, thermal expansion etc. In present work, eight linearized stiffness damping coefficients of cylindrical three lobe bearings are identified at different levels (twisting misalignment) speeds rotor. identification method used here needs FRFs (Frequency Response Functions) obtained by measurements finite element method. twisting changes vertical horizontal directions....

This paper investigates two winding concepts for Permanent Magnet (PM) machines used more electric aircraft systems where reliability is a concern. Analysis carried out using different surface mounted PM designed low and high speed applications: 12 slot, 10 pole machine with concentrated windings rotorcraft swashplate actuation 36-slot 6-pole distributed arrangement an starter-generator. The impact of the investigated focus on turn-turn Short-Circuit (SC) faults. Implications SC fault...

Abstract Misalignment between driving and driven machines is unavoidable. Flexible couplings are used to accommodate the misalignment. The flexible mechanisms in coupling impose moments on rotors connected. reaction forces developed due imposed act as periodic excitation rotating shafts. In present work effect of these vibration characteristics a two-stage turbine rotor-bearing system has been studied considering element coupling.