Search results for "Power density"
showing 7 items of 57 documents
Target Cooling Options for Neutron Sources at High Power Densities
2014
Abstract Compact neutron sources in many cases beat large ones when it comes to power density; thus, many issues concerning cooling are shared, and each party can learn a lot from the other facilities. Starting from accrued experience with water cooling at moderate power densities in SINQ over the last 15 years, a brief overview will be attempted showing the relevant parameters and specific approaches at several existing and planned neutron (spallation) sources. Extensions from the established ground of cooling with water will be sketched in two directions. An outline of an experiment planned for freshly determining in a representative geometry the hard limit for water cooling, i.e. full bo…
Impact of Nonlinear Inductor on Efficiency and Power Losses in a SMPS: a Case Study
2022
This paper proposes a comparative analysis focused on losses in two Switched Mode Power Supplies, adopting a linear inductor and an inductor operated up to saturation, respectively. The use of the nonlinear inductor saves weight and cost on the magnetic material, which is of great interest for automotive applications; however, it increases the peak current and can increase losses. The analysis aims to compare, by simulations, the impact on the efficiency of the different current waveforms throughout the converter. The losses are discussed in detail and calculated for each component of the converters.
A magnetostrictive generator for sensors network
2017
In this paper we present a vibration harvesting electric power generator based on magnetostrictive effect for sensors network in hazardous area and we validate it experimentally. The generator has been designed by using Dynamic Preisach hysteresis Model (DPM). DPM is a development of classical Preisach Model which is able to include dynamical features in the mathematical model of hysteresis. We measure the output power capability of the generator and we estimate its power density generation capability.
Design and Assessment of Optimized EMI Filters for Avionic Applications
2018
This paper presents a procedure to design EMI filters to reduce the electromagnetic disturbances generated by electrical apparatus used in avionic environment. The method proposed can be useful to save weight and size of the attenuation systems, and keep their effectiveness in agreement with the standard requirements. A design of a set of different filters with different topological characteristics is presented for a case study about an electrical actuator used for an aircraft onboard application. Performances and reliabilities of the attenuation systems are assessed by suitable full compliance experimental tests.
Non-Linear Inductor Models Comparison for Switched-Mode Power Supplies Applications
2022
The use of non-linear power inductors, intended as devices exploited up to a current at which the inductance is halved, is of great interest in switched-mode power supplies (SMPSs). Indeed, it allows the use of lighter and cheaper inductors improving the power density. On the other hand, the analysis of SMPSs equipped with non-linear inductors requires appropriate modeling of the inductor reproducing the inductance versus current. This paper compares two main analytical models proposed in the literature: the former is based on a polynomial, and the latter exploits the arctangent function to reproduce the non-linearity of the inductance. Performance is compared by considering the effort of r…
Design and Performance Evaluation of a High Power-Density EMI Filter for PWM Inverter-Fed Induction-Motor Drives
2016
This paper presents the design of an electromagnetic interference (EMI) filter for a low-voltage high-current induction-motor drives supplied by dc power grids. In order to effectively design the EMI filter, a suitable common-mode/differential-mode (CM/DM) separation technique has been used. Due to the high operating currents, the software-based separation technique using time-domain measurements has been applied. The proposed technique allows the CM and DM sections of the EMI filter to be properly selected in a more economical way, i.e., without the need of a dedicated hardware or costly radio frequency (RF) instrumentation. The design has been done according to a power-density criterion. …
EMI Worsening in a SMPS with Non-linear Inductor
2022
This paper is focused on the input current in a Switched Mode Power Supply (SMPS) in which the power inductor is exploited up to the saturation showing a non-linear behaviour. The input current exhibits a distortion due to the non-linearity. The electromagnetic interference (EMI) caused by the ripple at switching frequency, superimposed to the DC value of the input current, requires a suitable design of the input differential mode (DM) filter. The input current is analyzed both in the time and frequency domain for different operating conditions, and it is compared to a SMPS equipped with a traditional linear inductor.