Marco Villani

Finite-Element-Based Multiobjective Design Optimization Procedure of Interior Permanent Magnet Synchronous Motors for Wide Constant-Power Region Operation

This paper proposes the design optimization procedure of three-phase interior permanent magnet (IPM) synchronous motors with minimum weight, maximum power output, and suitability for wide constant-power region operation. The particular rotor geometry of the IPM synchronous motor and the presence of several variables and constraints make the design problem very complicated. The authors propose to combine an accurate finite-element analysis with a multiobjective optimization procedure using a new algorithm belonging to the class of controlled random search algorithms. The optimization procedure has been employed to design two IPM motors for industrial application and a city electrical scooter. A prototype has been realized and tested. The comparison between the predicted and measured performances shows the reliability of the simulation results and the effectiveness, versatility, and robustness of the proposed procedure.

High Reliability Permanent Magnet Brushless Motor Drive for Aircraft Application

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.

Multiobjective optimization techniques for the design of induction motors

This paper deals with the optimization problem of induction motor design. In order to tackle all the conflicting goals that define the problem, the use of multiobjective optimization is investigated. The numerical results show that the approach is viable.

Multi-phase permanent magnet motor drives for fault-tolerant applications

The recent markets crisis imposes the adoption of advanced technical solutions to match the requirements of energy efficiency, promoting a gradual transformation in the field of mechanical actuators for hazardous applications and moving the attention to more electric and efficient systems. Nevertheless the adoption of the electromechanical actuators are still limited in those fields that require a high degree of reliability, especially in the cases that involve huge hazard for peoples and environment or failures in systems characterized by heavy out-of-service or restarting costs. Multi-phase motor drives are gaining a growing interest because they permit a boost in torque and power density, allowing the design of very compact high efficiency drives with good improvement by the reliability point of view. The present paper recalls the basic concepts of multi-phase fault-tolerant design and illustrates their adoption in the development of two different systems for aircraft application such as a flap actuator and a cart lift system. Design details will be presented. Reports of analyses and tests carried out on the drives prototypes will be included to confirm the fault-tolerance capabilities with respect to the lack of one or two phases.

Multi-phase fault tolerant drives for aircraft applications

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.

Electromechanical Actuator for Helicopter Rotor Damper Application

Development trends in aeronautics involve a better employment of electric motors also in safety critical hazardous applications until now covered by mechanical systems. The electromechanical actuators (EMAs) are gaining a growing interest owing to their force and power density capability and the high dynamical performance by electronic control. Hence, very compact and high-efficiency drives can be designed, with satisfactory characteristics from the reliability point of view. This paper refers to a rotor damper system for helicopter application, using specifically designed permanent-magnet motors as EMAs. Design criteria and details will be presented focused on the integration of the electrical machine inside such specific application. Reports of analyses and tests carried out on the motor prototypes are included to confirm the capabilities and the performances of the proposed solution.

Fault-tolerant PM brushless DC drive for aerospace application

Reliability is a fundamental requirement in airborne equipments, it involves a particular approach of study on mission failure probabilities. Architectures robust to failure of single components like multi-phase fault-tolerant motors drives introduce in these systems an intrinsic improvement. By providing compensation for potential hardware failures, a fault-tolerant design approach may achieve reliability objectives without recourse to non-optimized redundancy or over-sizing. A fault-tolerant design approach differs from a pure design redundancy approach in that provisions are made for planned degraded modes of operation where acceptable. This study shows how a 5-phase motor is able to run at rated torque also with one or two phase open, by using suitable current commands defined as degraded modes. An experimental prototype has been arranged and tested.

Dynamic Analysis of Synchronous Reluctance Motor Drives Based on Simulink® and Finite Element Model

A fine motor analysis that takes the driving control into account allows to evaluate with a good accuracy the dynamic performance. The use of Simulinkreg together with FEA has allowed to investigate deeply the dynamic behaviour of the synchronous reluctance motor in different operating conditions, giving results closer to the actual motor performance

Analysis of fault-tolerant five-phase IPM synchronous motor

The choice of a multi-phase motor is a potentially fault-tolerant solution and gives rise to many advantages, respect to the traditional three-phase motor drives. In this paper an high torque density five-phase IPM synchronous motor has been studied, and the motor performance have been evaluated in the case of healthy-mode and faulty-mode operation.

Transient analysis of PM synchronous motor drives by finite element model co-simulation

This paper presents an analysis technique of electric motor drives based on transient simulation tools and embedded finite-element motor modeling (co-simulation). A couple of software tools, namely Cedrat Flux and Portunus, are employed suitably interfaced each other. The first one allows the computation of the motor electromagnetic behavior using a finite element model, while the second one allows the dynamic simulation of the control and feeding converter. The interacting use of these tools allows a detailed prediction of the motor transient behavior under a given control strategy and drive scheme. As test case a permanent magnet synchronous motor for biomedical application is considered, driven by field-oriented control. The co-simulation approach is at first compared with the (usual) lumped parameter modeling simulation and then verified by experiments. The results demonstrate that the co-simulation procedure allows taking into account not negligible phenomena, such as cogging and torque ripple, usually not considered in similar studies. Hence, co-simulation analysis represents a significant step for the integrate design of the motor and control, as well as a meaningful tool for electrical drives education.