Search results for "electromagnetic interference"
showing 10 items of 34 documents
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…
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.
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…
New circuital models of grounding systems and PDS for EMI analysis during a lightning strike
2005
In this paper circuital models of a Power Drive System (PDS) and of grounding systems are proposed in order to analyse Electromagnetic Interferences (EMI) induced in a PDS when a lightning current flows in the grounding system. The models have been developed adopting the network approach with lumped parameters and have been implemented using the software MATLAB. A High Frequency (HF) model suitable to simulate the impulse response of a PDS is described and a generalized method in order to calculate the lumped parameters values of grounding system models is presented. The new method takes into account the burial depth of electrodes as regards their length. The validation results of this new …
High frequency modeling technique for three phase power electronics module
2015
Nowadays, the high integrated power electronics modules (PMs), characterized by high speed, low loss and hard ware miniaturization, represent a new technology that meets the emerging demands of many applications, such us vehicle and home appliance, renewable energy sources in smart grid. The integration process and the high switching speeds increase the PM electromagnetic emissions that can create electromagnetic interference (EMI) with electric/electronic devices near the PMs. For this reason, electromagnetic compatibility (EMC) have to be carefully considered, yet in the design phase, to guarantee the reliability of PM systems. In this paper a method to develop a high frequency (HF) model…
Characterization of Different Cable Ferrite Materials to Reduce the Electromagnetic Noise in the 2–150 kHz Frequency Range
2018
The gap of standardization for conducted and field coupled electromagnetic interferences (EMI) in the 2–150 kHz frequency range can lead to Electromagnetic Compatibility (EMC) problems. This is caused by power systems such as Pulse Width Modulation (PWM) controlled rectifiers, photovoltaic inverters or charging battery units in electric vehicles. This is a very important frequency spectral due to interferences generated in a wide range of devices and, specifically, communication problems in the new technologies and devices incorporated to the traditional grid to convert it into a Smart Grid. Consequently, it is necessary to provide new solutions to attenuate this kind of interference, which…
Mechanical Properties of CNT/Polymer
2018
Abstract The high mechanical properties, the stiffness-to-weight and strength-to-weight make the carbon nanotubes a perfect reinforcing agents in advanced composites. This interesting potential has attracted the attention of both industry and academia that have committed to this research field an impressive amount of work. Several applications of carbon nanotubes enriched polymer composites have already been seen: aerospace structures, sporting goods, automotive components, medical devices, optical barriers, photovoltaic devices, conducting plastics, electromagnetic interference shielding, efficient electrostatic painting of plastics, composite mirrors, plastics with high thermal dissipatio…
Performance Study of Split Ferrite Cores Designed for EMI Suppression on Cables
2020
The ideal procedure to start designing an electronic device is to consider the electromagnetic compatibility (EMC) from the beginning. Even so, EMC problems can appear afterward, especially when the designed system is interconnected with external devices. Thereby, electromagnetic interferences (EMIs) could be transmitted to our device from power cables that interconnect it with an external power source or are connected to another system to establish wired communication. The application of an EMI suppressor such as a sleeve core that encircles the cables is a widely used technique to attenuate EM disturbances. This contribution is focused on the characterization of a variation of this cable …
EMI shielding effects of carbon nanotube cellulose nanocomposite
2010
Electromagnetic interference shielding is an important aspect of modern communication and computer technology. Carbon nanotube cellulose nanocomposite (CNTCNC) provides a novel material as an alternative to traditional metal-based shields for EMI shielding. Stratified structures containing CNTCNC layers combined with existing commercial lossy materials (like ferrite sheets) form effective EMI shields without lowering the signal integrity performance. Significant improvement in shielding effectiveness in stacked CNTCNC layers is noteworthy. CNTCNC is essentially like paper when it comes to flexibility and hence it can be easily conformed to the mechanical structure of the device in need of s…
Transmission Attenuation Power Ratio Analysis of Flexible Electromagnetic Absorber Sheets Combined with a Metal Layer.
2018
Electromagnetic noise absorber sheets have become a solution for solving complex electromagnetic interference (EMI) problems due to their high magnetic losses. This contribution is focused on characterizing a novel structure that is based on an absorber film with a metal layer attached on its top side. Two different absorber compositions were combined with Al and Cu metal layers in order to study the improvement on the performance of these structures, depending on the complex permeability, absorber film thickness, and type of metal. The transmission attenuation power ratio of the absorber films is analyzed and compared to the performance of absorber and metal structures. The measurement pro…