Search results for "electromagnetic [current]"
showing 10 items of 1008 documents
Immunity of a Virtual Instrument to conducted electromagnetic disturbances
2004
In the paper the performances of the Virtual Instruments under conducted electromagnetic disturbances are investigated, in order to find out if and how their metrological characteristics change with respect to the ones measured in absence of electromagnetic threats. The analysis is carried out by means of experimental tests, subjecting the AC power port of the systems under test to the conducted disturbances considered by the IEC-61326 standard and following the test procedures prescribed in the IEC-61000-4-series standards. The results show that the tested measurements instruments are sufficiently immune to these disturbances, since no variations of the distinctive parameters have been obs…
Control of an open-end winding induction machine via a two-output indirect matrix converter
2014
In this paper an Indirect Matrix Converter (IMC) with two output stages feeding an open-end winding induction machine is presented. The IMC has the advantage of having nobulky energy storage elements and with the two output stages up to 1.5 times the input phase voltage can be obtained across the windings of the machine, without overmodulation. A vector control scheme for the machine currents is used along with a modulation strategy for the converter two-output stages to reduce the common mode voltage and compensate the phase zero sequence currents. Simulation results showing the performance of the controlscheme and the reduction of zero sequence and common mode voltages are presented and d…
Virtual Instruments: Uncertainty Evaluation in the Presence of Electromagnetic Interferences
2007
The electromagnetic interferences can influence the performances of a virtual instrument; consequently, in a generic measurement performed by using these instruments, the related uncertainty values can increase. In the paper, we report the results of various experimental tests performed with the aim to check if and how the radiated and/or conducted disturbances affect the instruments' characteristics and, in particular, the single uncertainty sources. Starting from these results and applying an already proposed method for the uncertainty estimation in the measurements performed by means of virtual instruments, it is possible to take into account and to evaluate the contribute of the electro…
Wind Electrical energy generating systems EMC. A dedicated experimental simulator for tests
2008
In wind electrical energy generating systems, due to fast voltage and current fluctuations, the power converter represents a source of electromagnetic disturbances. EMI problems of stand alone wind generators are here analysed in order to take into account many different power quality problems which result in voltage fluctuations and harmonics in the net. This paper, moreover, presents a wind turbine experimental simulator (WTES) that moves a wind electrical energy generating system (WEEGS) to carry out EMI measurements and the relative experimental results. The WEEGS here taken into account comprises a wound rotor induction generator (WRIG) in which the frequency transformation from the ro…
Calculation of self and mutual inductances and 3-D magnetic fields of chokes with air gaps in core
2001
This work deals with the analysis of 3-D magnetic field in electric choke (reactor) with two windings. The analysis is related to the solutions of Laplace's and Poisson's equation by the Finite Element Method. The package OPERA-3d has been used. The self and mutual inductances of windings, which are connected in series aiding as well as in series opposing, have been determined. The calculation results of magnetic flux density components and the inductances are compared with the measured values.
Impact of industrial environments on the PC-based measurements
2007
In the paper we present a simple and fast procedure to evaluate the impact of the electromagnetic disturbances, which can be present in the industrial locations, on the measurements performed by a generic PC-based measurement instrument. The method is conceived starting from the data obtained by subjecting the instruments to the disturbances prescribed by the IEC-61326 standard. The results show that, even under heavy disturbances, the common good practices of shielding and grounding allow a correct employment of this kind of instrumentation.
2-D approach to the analysis of semianechoic chambers using a hybrid technique
2003
Semianechoic chambers are the most widely used emplacements for electromagnetic compatibility (EMC) tests. In this work a new and efficient technique for the analysis of 2-D simplified model of a chamber with arbitrary absorber is introduced and validated Some advanced results are presented, and a 2-D figure of merit for studying the overall behaviour of the chamber is proposed.
Cogging torque comparison of Interior Permanent Magnet Synchronous Generators with different stator windings
2017
This paper presents the comparison between the cogging torques produced by four IPMSGs (Interior Permanent Magnet Synchronous Generators) with different stator winding configurations. More in detail, an IPMSG model, which is derived from a commercial geometry, is analyzed through means of a FEM (Finite Element Method) approach. Then, three more structures are determined and analyzed by adequately changing the number of stator slots of the basic IPMSG stator structure and by maintaining the same rotor configuration. From the obtained simulation results, the cogging torque components for each structure are determined and compared. From this comparison, it can be stated that the use of dissymm…
Algorithmic method of design and analysis of fractional-slot windings of AC machines
1998
The paper presents a new algorithmic method of designing fractional-slot windings for AC machines of the double and single layer type. The method allows to design windings with a small number of slots per pole and phase, and then to analyse their MMF harmonic spectra in a simple systematic way and to optimise the construction. The presented method comprises not only 3-phase, but alsom-phase windings, which in the case of compact converter-motor units are quite applicable.
Evaluation of radiated EMI in 42 V vehicle electrical systems by FDTD simulation
2007
In this paper a full 3D numerical scheme, based on the finite difference time domain method, is used to predict the electromagnetic radiated interference generated by 42 V vehicle power electronic driven electrical loads. An experimental set-up has been arranged on purpose in order to validate the proposed simulation tool. To this aim, the features of a semi-anechoic electromagnetic chamber have been exploited in order to operate in a shielded test site for the measurement of near field radiated emissions. Two different three-dimensional geometrical configurations of realistic vehicle installations of the loads, are studied. A comparative analysis among measured and computed results is perf…