M. Scarano

A Tubular-Generator Drive For Wave Energy Conversion

This paper illustrates the operation of a tubular-machine drive as a linear generator for a heave-buoy wave energy conversion. Linear generators, which are adopted in marine power plants, offer the advantage of generating without introducing any conversion crank gear or hydraulic system. The use of a tubular-machine topology allows the electromagnetic thrust density to be improved. This paper briefly summarizes the principles of marine wave buoy interaction and reports the design analysis and control of a permanent-magnet (PM) synchronous tubular linear machine based on a scaled generator prototype and on a rotating simulation test bench

Single Wheel longitudinal traction control for electric vehicles

The traction control is a tool to increase stability and safety and it has a greater performance potential in electrical vehicles (EVs) than in internal combustions vehicles. Moreover, the traction control allows the EV to operate more efficiently preventing slippage in acceleration and permitting the use of use high-efficiency low-drag tires. The presented approach can compete with the well-recognized techniques, but it offers a lighter tuning procedure. This paper presents an approach to the longitudinal control of a single wheel adopting a configuration based on an adherence estimator and a controller of the adherence gradient. Two adherence gradient controllers are examined in the paper: a fuzzy controller and a sliding mode controller. In both cases, the presented approach allows for tracking a value of the adherence derivative in a wide operating range without any knowledge of the road conditions. The work is based on numerical simulations as well as experimental tests. The test bench computes in real-time the vehicle dynamic and loads accordingly, the drive under test. Both controllers were experimentally verified showing good behavior and good response to a sudden change in the road characteristics, whereas the best overall performance was recorded with the sliding mode control

A tubular generator for marine energy direct drive applications

The paper illustrates the operation of a tubular machine as a linear generator for reciprocating energy sources. Reciprocating energy sources utilization is rapidly increasing nowadays due to the interests in marine energy. Linear generators adopted in marine power plants, offer the advantage of generating without introducing any conversion crank gear or hydraulic system. The use of tubular machine topology allows to improve electromagnetic thrust density. The paper shortly summarizes the principles of the marine wave buoy interaction and reports the design analysis and control of a PM synchronous tubular linear machine based on a scaled prototype

Design of a System-on-Chip PMSM Drive Sensorless Control

The Sliding-Mode Position and Speed Observer is a simple and well-known mechanical sensor-less solution for Permanent Magnet Synchronous Motors (PMSMs) that is inherently robust in the medium-high speed range. The paper proposes a Field Programmable Gate Array (FPGA) implementation of a simple observer exploiting the high computational power of the device aiming to improve the speed estimation behavior and to make a step towards a System on Programmable Chip (SOPC) sensor-less PMSM drive.

Induction motor faults diagnostic via artificial neural network (ANN)

The paper deals with the analysis of an artificial neural network (ANN) approach suitable for online faults detection of induction machines. The aim of this paper is to develop an alternative with respect to traditional fault detector techniques that overcomes the limitations of present technology. After an analytical discussion about theoretical principles and relations used for the diagnosis of electrical machines failures, a simple ANN algorithm is presented and tested. The results prove the feasibility of to tool arranged by means of artificial neural network for a fast and accurate detection of stator faults in induction machines. Furthermore a good accuracy of the results have been achieved notwithstanding the great simplicity of the algorithm with respect to a complete model arranged by a space vector analysis.<<ETX>>

Analytical formulation of the no-load magnetic field in IPM tubular machines with translator eccentricity

The design of electrical machines requires a suitable procedure in order to highlight the main machine parameters. Among them, the knowledge of the no load magnetic field as a function of the main geometry machine parameters helps designers in formulating optimal design choices. Inevitably, tubular machines are subject to eccentricity of the mover, therefore a non uniform distribution of the no load magnetic field in the air-gap arises. This yields attractive radial forces that must be taken into account in the choice of the bearings. This paper illustrates an analytical formulation of the no load magnetic field distribution in tubular IPM machines with translator eccentricity in order to facilitate the computation of the radial forces

Selecting the electromagnetic actuator of the ELT primary mirror

The segmented, adaptive primary mirror of the ELT is the most delicate optical component of the telescope. Its full-adaptive operational modes require an high bandwidth actuation system, able to provide large and precise stroke motions. As the core component of the actuation system hardware, the electromagnetic device has to be accurately designed. This paper depicts the preliminary electromagnetic study of the actuator. After a discussion of the chosen concept, the design process and the computational approach are illustrated. The goal of the study is the definition of the basic geometrical and physical parameters which allow the minimization of the power dissipated to deliver the proper actuation force, in order to reduce the local overheating in the telescope optical path.

Traction Control for a PM Axial-Flux In-Wheel Motor

The traction control is a tool to increase stability and safety of vehicles and it has a greater performance potential in electrical vehicles than in ICV. Moreover, the traction control allows the EV to operate more efficiently preventing slippage in acceleration and permitting the use of high-efficiency low-drag tires. The presented approach can compete with the well-established techniques, but it offers a lighter tuning procedure. This paper presents an approach to the longitudinal control of a single wheel adopting a configuration based on an adherence estimator and a controller of the adherence gradient. The presented approach allows tracking of the value of the adherence derivative in a wide operating range without any knowledge of the road conditions. The work is based mainly on experimental tests. the test rig computes the vehicle dynamics in real-time and loads accordingly the drive under test. The controller was experimentally verified showing good behavior.

Performance Evaluation for a HTS Transformer

The adoption of High Temperature Superconductors (HTS) tapes is becoming a suitable and interesting alternative to copper for windings in transformers, thanks to the improvement in performance and the lowering of costs. Of course, optimized designs, different with respect to usual layouts, must be considered, due to the additional requirements of HTS tapes, such as minimization of orthogonal magnetic fields and consideration of additional losses in the HTS. In the framework of a scientific cooperation among some Italian Universities and private companies, a test model for a 10 KVA transformer with HTS secondary windings has been developed, and validated against a demonstrative prototype, manufactured during the project. In the paper, the device model performance is assessed, with particular care to the HTS losses modeling, and some comparisons to the experimental results are presented

Analytical Formulation of Radial Magnetic Forces in PM Linear Tubular Machines with Translator Eccentricity

Due to mechanical couplings, permanent magnet tubular linear machines are subject to eccentricity of the mover and hence to a non uniform circumferential distribution of the no load magnetic field in the air-gap. The intensity of radial forces arising thereof is such that it must be taken into account both for flexion analysis and for choice of bearings. This paper illustrates an analytical formulation of the no load magnetic field distribution in tubular IPM machines with translator eccentricity in order to facilitate the computation of the radial forces. Measurements on two prototypes in a test rig illustrate the validity of the approach.