Search results for " inductor"

A Measurement System for Power Inductors in Non-Linear Operating Conditions

2021

The exploitation of power inductors in switching converters outside the linear region requires detailed information on the magnetization curve that often is not included among those usually available on their datasheets. This paper proposes an automatic system in which the inductor is characterized in real operating conditions taking into account also the core temperature. It is based on a switching converter suitably controlled by a virtual instrument. The system was tested by retrieving the inductance vs current curves of two commercial inductors for core temperatures up to 105°C, showing the different behaviors of the magnetization curves. Results are coherent with data given by manufact…

Thermal Stability of a DC/DC Converter with Inductor in Partial Saturation

2021

Inductors operated in quasi saturation in dc–dc converters allow reduction of the core size and realization costs; on the other hand, they imply an increase of dissipated power that can jeopardize the thermal stability of the converter. In this article, this issue is studied by a mathematical model able to represent both the inductor nonlinearity and its temperature dependence. The main losses, such as ohmic, skin effect and magnetic, are taken into account in the model. The inductor is characterized by a polynomial curve whose parameters are a function of the temperature. Finally, the whole converter is modeled and simulation results, obtained on a boost converter, are compared with experi…

Characterization of inductors in partial saturation including thermal effects for DC/DC converters

2018

Modern switching power electronic converters are widely used in many industrial and consumer applications, especially in step-up and step-down configurations. The optimization of the inductor in the converter design gives advantages in terms of power density increase and cost reduction; therefore, to properly design the converters, it is necessary to improve the knowledge of magnetic material behaviour as the current changes. The development of new models is becoming crucial in the design of modern power converters and there are some recent papers dealing with the use of inductors working in partial saturation [1-5]. This issue is of great interest for scientists and industry due to economi…

NON-LINEAR INDUCTOR CONTRIBUTION TO HARMONIC SPECTRUM IN POWER CONVERTERS

The paper investigates the harmonic content in DC/DC power converters where the inductor is operated in the non-linear region. This operation is often exploited to use lighter and cheaper inductors; as a drawback, an increasing number of harmonics is noticeable. A theoretical analysis is proposed. It is based on a polynomial model of the inductor used in a boost converter. Results are given by the spectra of the output voltage performed on a circuit prototype.

Self-Heating Induced Instability of a Non-Linear Inductor in a SMPS: a Case Study

2023

This paper proposes a case study to show that the non-linear operation of a power inductor in a SMPS can induce instability of the control system leading to overheating of the inductor beyond its allowable temperature and to an excessive peak of the maximum current. The case study is performed by a commercial ferrite inductor employed in a synchronous boost converter encompassing a control system to adjust the duty cycle, assuring a constant output voltage. The thermal transient is described by the time domain waveforms and thermal images.

A Temperature Dependent Non-Linear Inductor Model for a DC/DC Boost Converter

2018

This paper is focused on the use of non-linear inductors in DC/DC switching converters, as well as their behaviour due to changes in current and temperature. The model of an inductor is set up on the basis of experimental data, which are automatically acquired by a virtual instrument; from those data, a polynomial curve describing the inductance variations is obtained. The analysis of the converter, performed by including the proposed model, is validated by experimental tests.

Characterization of inductors in partial saturation for SMPS applications

2017

The exploitation of partially saturated inductors in Switching Mode Power Supply (SMPS) is a key strategy for reducing the size of SMPS and increasing their power density [1]. However an accurate characterization and modellization of each inductor is needed for a correct design and control of the SMPS [2]. Most of inductors' datasheets only indicate the nominal inductance at low current. Anyway, when the inductor is subjected to a higher current, the value of the inductance is lessened. Moreover, inductance meters often actuate their measurements at no or moderate DC bias. In this work we describe the realization of an automated test bench (Fig. 1) for characterizing an inductor under varia…

Investigation of PCB-based Inductive Sensors Orientation for Corona Partial Discharge Detection

2022

This paper presents an experimental investigation of two different printed circuit board (PCB) inductive sensors, with meander and non-spiral shapes, to assess their capabilities and best orientation for corona partial discharge (PD) detection. First, simulations with the Ansys HFSS software are performed in order to evaluate the equivalent electrical circuit of the two sensors and their 2d radiation patterns. The meander sensors presented a resonant frequency of 600 MHz, while it was around 1.1 GHz for the non-spiral. The 2d radiation pattern showed that better sensitivity is achieved when the inductive sensor is oriented 90 degrees with respect to the PD source. Experimental tests showed …

Development of an Inductive NIS Thermometer

2012

We have studied an inductive readout for normal metal-insulator-superconductor (NIS) tunnel junctions by using on-chip planar inductors and a DC SQUID (superconducting quantum interference device) to develop a sensitive and fast thermometer for studies of nanoscale heat conduction and bolometry. Our initial results show the feasibility of the concept, with a good sensitivity for temperatures below 1 K for aluminum as the superconductor when voltage biased close to the superconductor energy gap. peerReviewed

EMI Filter Re-Design in a SMPS with Inductor in Saturation

2021

This paper analyzes the design issues of the input EMI (Electro-Magnetic Interference) filter's in a switching mode power supply where the power inductor is operated in saturation. Starting with a SMPS equipped with linear inductor, the input filter is firstly designed to comply with Standards. Then, a new inductor with a smaller core size is employed in the same SMPS to exploit saturation. The EMI filter is re-designed, taking into account the increase of EMI introduced by the non-linear operation of the inductor. Finally, the reduction of the inductor's size and cost is compared with the increased size and cost of the EMI filter.