Mosè Castiello

Experimental Comparison of PM-Assisted Synchronous Reluctance Motors

The aim of this paper is to show the results of various experimental tests carried out on synchronous reluctance (REL) motors with different rotor geometries, as proposed in technical literature. The impact of the assistance of ferrite permanent-magnet (PM) inset in the flux barriers is considered: PM-assisted REL motors are compared with synchronous REL motors, highlighting the main benefits of the former solution. The effect of the rotor skewing and of adopting asymmetric geometries of the flux barriers to reduce the torque ripple is investigated by means of several tests. The impact of the lamination is also considered, as far as the overload capability is concerned. In addition to the experimental tests, a finite-element model is adopted to predict the performance of the motors. The predicted results are compared with the experimental ones in a wide operating range, showing a good agreement.

Electric Vehicle Traction Based on Synchronous Reluctance Motors

It was recently demonstrated that the synchronous reluctance motor is well suited for electric as well as for hybrid electric vehicles. This paper deeply investigates the capabilities of a synchronous reluctance motor and compares them with those of a permanent-magnet-assisted synchronous reluctance motor, according to the typical requirement of a traction application. A proper rotor design is necessary. The average torque is due to the rotor anisotropy. The permeance difference between the direct- and the quadrature-axis is achieved by means of a high number of flux barriers. The position of the flux barrier ends and proper rotor asymmetries are chosen so as to reduce the torque ripple, mainly due to the slot harmonics. The impact of the rotor design on the motor performance is presented deeply, showing several simulation and experimental results, carried out on synchronous reluctance motors with different rotor geometries. Permanent magnets can be inset in the flux barriers to assist the synchronous reluctance motor improving its capabilities, but avoiding to use rare-earth permanent magnets. The main advantages of the permanent magnet assistance is an increase of the main torque density and of the power factor. They are evaluated experimentally. However, the drawback of adopting permanent magnets is the possible demagnetization of the magnets themselves. This can greatly limit the maximum overload capability of the motor, which is a salient requirement of a traction motor.

Experimental comparison of PM assisted synchronous reluctance motors

The aim of this paper is to show the results of various experimental tests carried out on synchronous reluctance (REL) motors with different rotor geometries, as proposed in technical literature. The impact of the assistance of ferrite permanent-magnet (PM) inset in the flux barriers is considered: PM-assisted REL motors are compared with synchronous REL motors, highlighting the main benefits of the former solution. The effect of the rotor skewing and of adopting asymmetric geometries of the flux barriers to reduce the torque ripple is investigated by means of several tests. The impact of the lamination is also considered, as far as the overload capability is concerned. In addition to the experimental tests, a finite-element model is adopted to predict the performance of the motors. The predicted results are compared with the experimental ones in a wide operating range, showing a good agreement.

A test bench for hybrid propulsion train research and development

This paper presents a versatile laboratory test bench built up for carrying out researches and experimental tests about hybrid propulsion trains, without the availability of a real vehicle and an automotive test track. The test bench is realized by using a relatively low-power engine that can be combined with one or more electrical machines for emulating different hybrid architectures. In addition to the test bench structure, some examples of usage are also described in the paper.

A new grid electrode for electrochemotherapy treatment of large skin tumors

Electrochemotherapy (ECT) is a local anticancer treatment for superficial tumors which involves the administration of a chemotherapeutic drug followed by short, high-voltage pulses. Incipient clinical experience with breast cancer patients are encouraging, with a local complete response rate ranging from 50 to 90%. However, since many patients present with multiple or widespread metastases, ECT, despite its high local antitumor efficacy, need to be applied several times in order to complete treatment delivery or maintain tumor control during the follow-up. In this paper, we propose the prototype of a new grid electrode aimed at the improvement of ECT application. The device is suitable for treating large, tumor-infiltrated skin surfaces as in breast cancer patients with chest wall metastases after mastectomy. According to our tests in different in vitro models, the new device allows to apply the voltage pulses more quickly and homogeneously when compared with standard pulse applicators. This technical advancement holds promise for improving ECT outcome and, hopefully, for sparing a number of patients from the need of multiple treatments.

Electric vehicle traction based on a PM assisted synchronous reluctance motor

It is recently demonstrated that the synchronous reluctance motor is well suited for electric as well as for hybrid electric vehicles. Of course, a proper rotor design is necessary, since the main torque is due to the rotor anisotropy, that is, the permeance difference between the direct- and the quadrature-axis. The flux barrier ends are placed so as to reduce the torque ripple due to the slot harmonics. The torque ripple is also reduced adopting rotor asymmetries. The impact of the rotor design on the motor performance is presented deeply, showing several experimental test results carried out on synchronous reluctance motors with different rotor geometries. Permanent magnet can be inset in the flux barriers to assist the synchronous reluctance motor improving its capabilities. The main advantages and drawbacks of the permanent magnet adoption are highlighted.

Interior permanent magnet integrated starter‐alternator

Purpose – The purpose of the paper is to present a complete design example of an interior permanent magnet integrated starter‐alternator (ISA).Design/methodology/approach – After a preliminary design on the basis of an analytical model, finite element simulations are adopted to refine the design of the machine.Findings – The designed ISA drive is able to satisfy all the requirements of modern cars, where the power of the electrical generators is increasing to deliver the on‐board power demand. The drive exhibits high torque, driving start, and a wide constant power speed range driving generation.Originality/value – The entire system design is considered in the paper, both the electrical machine and the control strategy.

Model Predictive Hysteresis Current Control for wide speed operation of a Synchronous Reluctance machine drive

This work presents a novel Model Predictive Hysteresis Current Control scheme for Synchronous Reluctance machine. The proposed algorithm predicts the plant behaviour considering the finite set of the power converter states and it chooses the most suitable voltage vector in order to reduce the current amplitude error and to minimize a cost function. The latter is designed to meet different goals depending on the operating conditions of the machine. In particular the Maximum Torque Per Ampere trajectory, the Flux Weakening region and the Maximum Torque Per Voltage operation are considered. In this way, a wide speed range operation is achieved and the current and voltage limits are inherently observed. The effectiveness of the control scheme is proved by mean of experiments.

An SPM Motor Drive Dressed as IPM Motor Drive for a Flexible Test Bench of Salient Rotor Propulsion Machines

The design of the powertrain of electric vehicles and hybrid electric vehicles could require the testing of different electrical machines in order to evaluate their performances and to find the most suitable solution for that specific propulsion system. The number of electrical machines that can be tested is limited by economical and practical issues. Moreover the numerical simulations cannot always represent a reliable mean to understand the real behaviour of the system. This paper presents a new mathematical model to emulate different virtual machines using only one real machine.

On the effect of the rotor polarity on the performance of fractional Slot SPM machines

Concentrated winding fractional slot permanent magnet (PM) machines are currently considered as viable candidates for various applications. These machines offer many advantages over distributed winding PM machines, especially: reduced copper losses thanks to short end-windings, wide flux-weakening range, improved fault-tolerance capability, low cogging torque. These performance could not be accessed without a convenient selection of the slot-pole combinaisons. Within this background, the paper deals with a FEA-based investigation of the torque production capability exhibited by two topologies of fractional slot surface-mounted PM machines sharing the same number of slots in the stator while they differ by the number of poles in the rotor. The FEA results are validated by experiments carried out on prototypes of the machines under comparison.