TIEG: basic information of the research group

This paper presents a summary of the main activities of research group TIEG (Terrassa Industrial Electronics Group). The group objectives are basically focused on four main areas, i.e. Electromagnetic Compatibility (EMC) in power systems ; EMC in integrated circuits ; power electronics for energy management ; power electronics for motion controlPeer Reviewe

Effect of driver to gate coupling circuits on EMI produced by SiC MOSFETS

This work presents a study of the influence of different gate driver circuits on the switching behavior and EMI produced by SiC MOSFET devices used in a boost converter. The paper includes several simulations of switching behavior using different VGS voltage levels and different passive RCD (Resistance Capacitor Diode) circuits to interface the driver to the SiC MOS gate and several tests of conducted and radiated EMI for each one of the interface circuits. The paper also includes a comparison of both aspects (switching and EMI) when using different gate voltage levels. The study reveals that gate voltage has little impact on switching behavior and therefore on conducted and radiated EMI, while gate RCD coupling circuits have a noticeable impact. The EMI reduction, when using the adequate driver-gate circuit may be in the order of 10 dB at certain frequencies in the conducted band and up to 20 dB for certain frequencies in the radiated band.Postprint (author’s final draft

Experimental measurements about harmonic current mitigation of electric vehicle battery chargers

The expected high penetration of battery chargers for electric vehicles (EV) in electric networks is foreseen as a potential problem for power quality. Battery chargers are nonlinear devices that inject harmonic currents and pollute network voltages. Thus, their harmonic emissions must be analyzed and reduced by harmonic mitigation techniques to avoid future problems. This paper analyzes and reports some real case measurements of harmonics injected by single- and three-phase battery chargers and their attenuation using line choke inductances.Postprint (published version

Nonlinear loads model for harmonics flow prediction, using multivariate regression

This paper describes a method for obtaining a model of a single or a set of nonlinear loads (NLL) connected to a certain point of an electrical network. The basic assumption is that the network supplying the NLL has significant series impedances and is disturbed by other parallel, random, and unknown neighbor loads, sharing part of the supply system with the NLL. The main interest for obtaining the model is its further use to predict the amount and flow of harmonic currents generated by the NLL, in the case of adding a filter to reduce the harmonics distortion. The modeling technique used in the paper is based on multivariate multiple outputs regression and leads to a set of equations giving the NLL behavior (one for each of the harmonic currents). The model is obtained from data taken at measuring point and is only valid to predict the NLL behavior when new loads are connected at this point. The modeling method was first tested with V, I data coming from simulations using a MATLAB-Simulink SimPowerSystems toolbox. Finally, the method has been validated using V, I data taken in a real installation with different neighbor loads and under different load conditions.Postprint (published version

Common mode output waveform reduction for matrix converter drives

This paper presents an alternative Space Vector Modulation (SVM) implemented in Matrix Converters (MC) which improves and reduces the Common Mode (CM) voltage and current output waveforms. The strategy is based on replacing the MC zero vectors for the rotating ones, which reduces the CM voltage derivative and therefore the leakage CM current. By reducing this CM current, which might flow inside the motor through the bearings and windings, the Permanent Magnet Synchronous Machine (PMSM) deterioration might be slowed down. The paper describes the novel SVM pattern and analyses the CM voltage and its leakage current. Simulation results based on PMSM drive are provided to corroborate the whole idea.Peer ReviewedPostprint (published version

Lead current reduction in a three phase four wires Shunt Hybrid Filter

Peer ReviewedPostprint (author’s final draft

Interleaving and switching pattern modulation to conducted EMI reduction

This paper explores new techniques to reduce the conducted EMI generated by switched power converters operating in multiconverter arrangement. These techniques are based in the combined application of interleaving and the modulation of some characteristics of the switching patterns. The effectiveness of such methods in terms of EMI reduction is theoreticaly developed and experimentally validated in a four channel parallel buck converter operating in closed loop. The technique that provides the best attenuation results is identified. Finally, undesired sideeffects produced by these techniques, such as an increase in the output voltage ripple, are evaluated.Peer ReviewedPostprint (published version

Contribution to conducted EMI reduction in multiconverter topology

This paper contributes to the conducted EMI reduction generated by switched power converters operating in multiconverter arrangement. The EMI reduction is achieved by means of the combination of two techniques: interleaving and switching frequency modulation. The effectiveness of such methods in terms of EMI reduction is experimentally validated in a four channel parallel buck converter. The technique that provides the best attenuation results is identified. Finally, special attention has been paid to possible undesired side-effects produced by these techniques. For this reason the converter efficiency and output voltage ripple are evaluated.Peer ReviewedPreprin

A new switching frequency modulation scheme for EMI reduction in multiconverter topology

This paper presents a modulation scheme in order to reduce conducted Electromagnetic Interference (EMI) generated by modular power converters with parallel topology. The proposed scheme is based on a combination of interleaving and Switching Frequency Modulation (SFM) techniques. The objective of this modulation scheme is to cancel certain harmonics of EMI and to reduce the amplitude of the remaining harmonics. The proposed scheme has been implemented in a field programmable gate array and a four channel parallel buck converter has been used in order to verify it. A significant EMI reduction has been obtained in comparison to use the interleaving and Switching Frequency Modulation separately.Peer ReviewedPostprint (published version

Hard-less common mode active EMI filter

Active EMI filters appear as an alternative to classical EMI filters based on passive components. Active EMI filters can provide more compact, cheaper and lighter solutions than passive approach. In this paper we present a theoretical analysis of the 4 possible configurations. Expressions of the transfer function and insertion losses considering impedances of mains and source of noise are presented. The voltage-current topology is identified as the more convenient solution. Finally, preliminary experimental results of a prototype capable to provide attenuation up to 100MHz are shown.Peer ReviewedPostprint (published version