Reliability is a fundamental requirement in aircraft safety-critical equipments. Its pursuing involves the adoption of protective design concepts such as fault-tolerant or redundant approaches, aiming to minimize mission failure probabilities. Multi-phase motor drives are gaining a growing interest to this extent, because they permit a boost in torque and power density, allowing the design of very compact high efficiency drives with intrinsic fault-tolerant capabilities. This paper presents a five-phase permanent magnet brushless motor drive developed for an aircraft flap actuator application. The motor is designed to satisfy the load specifications with one or two phases open or with a phase short circuited, while a failure in the rotor position sensors is remedied through a sensorless strategy. Design studies aiming to predict the faulty mode performance in case of different remedial strategies are presented. Experimental tests on the drive prototype are included, which confirm its capability to satisfy the planned degraded modes of operation.

This paper deals with the design of high-speed Synchronous Reluctance motors for electric vehicle applications. The need to enhance the power density and to lower the cost leads to research on high speed motors with a reduced amount of rare earth. Pure Synchronous Reluctance motors potentially operate at high speed and exhibit a cost-effective rotor compared to PM and induction motors. Nevertheless, they present reduced performances in deep flux weakening operations, in particular when the so-called radial ribs are introduced to increase the mechanical robustness of the rotor. In this paper the introduction of the radial ribs and the related design challenges are investigated and discussed. The adoption of the topology optimization tool that is able to optimize the amount, the positioning and the sizing of suitable structural ribs is presented. A design flow integrating the Topology Optimization is presented. The approach leads to an original positioning of the radial ribs able to preserve the performance of the motor at high operating speed enhancing the mechanical integrity of the rotor.

This article presents the definition of the performance that the electric motor should have in order to satisfy the requirements of the electric vehicle in terms of acceleration time and maximum speed, starting from a simplified vehicle model, considering the motor torque minimization and the input power minimization. In order to verify the effectiveness of the synchronous reluctance motor in traction applications, it has been evaluated in two case studies: a high-performance vehicle and a city car, where different flux weakening capabilities from the motor in function of the minimization strategies can be pursued to satisfy the requirements. If the car requires high performance in terms of acceleration time and maximum speed, the poor flux weakening capabilities of the synchronous reluctance motor induces a machine oversizing in terms of peak power; by assuming this, it is, however, possible to satisfy the requirements considering the maximum available encumbrance due to an advanced and innovative optimized design procedure. The motor of the city car is obtained only by modifying the stack length and the windings (scaled version), and on this last solution, a prototype has been realized and fully tested; the experimental tests confirm the results of the simulations.

The demand for high reliability motor drives increases every day, especially in aircraft where traditional, nonelectric systems (hydraulic, pneumatic) are being replaced by electrical actuators following the More Electric Aircraft (MEA) trend. Electric drives for aerospace need a fault-tolerant design approach to achieve reliability objectives with optimized architectures reducing redundancies, over-sizing and costs. The presented work shows how fault tolerant design methodologies can be applied in two motors for typical aircraft application such as a Cart Lift System (CLS) and a Flap Actuator (FA). Analyses and tests are reported to demonstrate how the designed multi-phase motors are able to run at rated torque also with one or two phases faulted.

This paper deals with the design of a 200kW/ 370Nm, induction machine for electrical vehicles traction system. The design aims to enhance the performance of the current induction machine technology for mass production making it suitable to be a rare earth free solution for electric vehicle applications. To this extent, suitable materials have been analyzed and selected, also by using of mechanical analysis and experimental data. Rotor die-casting, hairpin stator winding and specific cooling systems have been adopted within the proposed solutions. Extensive analytical and numerical methods are used for performance evaluation all over the full speed range of the machine.