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The aim of this work is to evaluate how design parameters of a power pad for an electric vehicles wireless charging device have an effect on the exposure of people to electromagnetic fields. The effectiveness of magnetic field shielding method by means of conductive panels is analyzed. The shielded coreless transformer has been modelled and examined through Finite Element software. The overall system's...
Inductive power transfer is a near-field technology for the transmission of electric energy via oscillating magnetic fields by inductive coupling between coils. The main issues related to this technology are the large air gap between coils and the lack of any ferromagnetic core, resulting in a weak coupling between transmitter and receiver coils and large leakage flux. Loosely coupled inductive power...
Electric vehicles are every day more and more important and diffuse in all day life. They represent a new prospective mode of transportation to address environment issues. The major drawbacks of the present electric vehicles are the long charging times and mechanical hassles with charging cables. The contactless battery charging is a challenging solution to overcome these issues. This paper deals...
Torsional vibration issues in elastic drive systems are a well-known topic also in the industrial field. The torque pulsations produced by the drive are the main causes of these torsional resonance excitations. However, it will be analysed in this paper how some side-effects in the control strategy, like the latencies, are critical as the torque ripple. Indeed, the suppression of this vibrations phenomenon...
Magnetic levitation is a powerful phenomenon which, if correctly controlled allows frictionless relative motion between two bodies. Active Magnetic Bears use this characteristic to allow the rotation between stator and rotor without contact, but typically, the small airgap does not allow an active dumping of the mechanical vibrations. This paper presents a new large airgap magnetic bearing that allows...
In these years, Inductive Power Transfer (IPT) has progressed to be an effective system for electrical vehicles batteries charging because it offers significant benefits in terms of safe operations even in wet and dirty environment. This paper investigate the design of a disc structure for the energy transmission over an airgap of several hundred millimetres. The main characteristic of the proposed...
The axle strain monitoring is an effective technique to prevent massive damage to the train. The measurement of the axle strain needs rotating sensors, data acquisition and data transmission units that have to be electrically powered. This paper presents a high frequency induction power feeding system that can be directly mounted on the train axle in a very stable and safety way. The system equations...
The problem of energy saving is, at present, more and more important and the reduction of the consumption of the vehicles is a target that a lot of countries and car manufacturers are searching for. In this scenario Shell organizes a competition called Shell Eco Marathon; the winner of this race is the team that realize the vehicle capable of covering a fixed distance with the lowest fuel consumption...
The need to decrease pollution in urban zones has pushed toward severe regulations in term of low-emission limits. The effect of this “environmental awareness” is an increased interest in Light Electric Vehicles (LEV). The construction of a LEV is presented in this paper. This vehicle has been designed specifically to be powered by electric motors, the suspension system and the general layout have...
Reduction of pollution, implementation of intelligent systems and the increment of safety are some of the main concerns in the automotive sector in Europe. To give an answer to these concerns, project GreenFun is proposed as an innovative 4WD Light Electric Vehicle (LEV) prototype, endowed with special features aimed to make it eco-friendly, enjoyable and safe. This paper present the design and the...
The application of an energy transmission system to a rotating shaft by using a counter-weighted-free-wheeled-rotor permanent magnet synchronous machine is analyzed in this paper. This solution avoids slip rings and can generate a power amount which can be significantly higher if compared to other contact-less solutions. The guidelines for the design of such a machine are discussed by considering...
The voltage distribution inside a machine's winding is analyzed in this paper. The use of a simple distributed parameters coil model allows to predict, in a qualitative way, the value of the peak voltage as a function of the winding length. Thanks to a simple algorithm, the voltage peak distribution is analyzed as a function of the coil constructive parameters like the capacitance-to-ground and the...
An induction motor model construction and the validation of the model response to a filtering technique is analyzed in this paper. The filter is connected to the rotating machine terminals in order to suppress overvoltages due to the long cables and high frequency pulses of the inverter. With the help of high frequency measurements made by the authors on a 1.1kW induction motor, an accurate simulation...
In recent years, the interest in offshore wind farms has been increased significantly. One of the reasons of this development is the less perceived environmental cost of an offshore wind farm with respect to an in-land one, especially for new installations where big turbines are preferred. However, they have also the advantage of an increased and more constant wind speed, leading to higher and more...
This paper deals with the performance of some numerical integration methods for Ordinary Differential Equations in real time applications involving stiffness. After summarising the main results about accuracy and stability of some well known schemes, the point of view of the control is emphasized, by showing the impact of the numerical integration on the dynamics of the discretized model. Moreover...
An on line partial discharge test technique on rotating machines fed by inverters is analyzed in this paper. All the research to determine the configuration of the components was developed using simulation in Matlab Simulink™. The important fact is that the entire model was made with all the components and situations that result from partial discharges on the insulation of electrical rotating machines...
The paper deals with a novel MRAS observer for the sensorless control of a Doubly Fed Induction Machine. In the proposed MRAS, an expression of the electromagnetic torque and the norm of the rotor current space vector are exploited to form the reference model. The formulation of the MRAS and the linearised model are discussed and the differences with respect to other observers are highlighted. Finally,...
The large number of high power conversion applications has brought to the development of complex power converter configurations. A wide class of such converters are based on Power Electronic Building Block (PEBB) constituted of two level modules. Modulation strategies can take advantage of the modularity of these power converter topologies proposing modular and general control strategies. The present...
This paper describes an innovative Medium Voltage Direct Current electrical grid system (MVDC) for wind farms, based on transformer-less wind turbines, equipped with modular, multilevel converter (M2LC). A comparison between this MVDC system and a traditional MVAC one has been done using EECC (Electrical Energy Conversion Cost) index in order to evaluate the competitiveness of this solution for an...
This paper deals with a performance analysis of sensorless drives based on doubly fed induction machines. A simplified model of the whole system equipped with a generic model reference adaptive system (MRAS) observer is introduced, by taking also into account a mismatch in the parameters. Three MRAS known in literature are analyzed in detail and meaningful analytic relations between the mismatched...
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