Piotr Musznicki

Bio: Piotr Musznicki is an academic researcher from Gdańsk University of Technology. The author has contributed to research in topics: Electromagnetic interference & EMI. The author has an hindex of 6, co-authored 24 publications receiving 131 citations.

Accurate modeling of layout parasitic to forecast EMI emitted from a DC-DC converter

Abstract: This paper illustrates how to account for all parasitic due to the layout of a power converter (inductive and capacitive), in order to forecast electromagnetic interferences (EMI). The method is generic, and is validated here in the simple example of a DC-DC converter, realized on different technologies: insulated metal substrate (IMS), printed circuit board (PCB). In addition, several layouts aspects will be investigated. Conclusions are given on the influence of layout and all other components on EMI.

The Wiener Filter Applied to EMI Decomposition

Abstract: This paper presents a DSP method that allows decomposing conducted electromagnetic interference (EMI) emissions from different sources in large power electronics systems. The estimation process is carried out by a number of Wiener filters (WFs), which represent all different converter states. These are determined by initial commutation event conditions and propagation paths layout. Filters are fed by a semiconductor power switch voltage or current waveforms regarded as sources of perturbation. The EMI emissions are measured on the line impedance stabilization network (LISN) terminals. Optimal filter adaptation is carried out in the frequency domain by measuring and computing input and cross-power signal spectra. Analysis of a parallel quasi-resonant DC-link voltage inverter (PQRDCLI) is outlined to distinguish filters assigned for inverter operation from those for external DC/DC converter interaction. Experimental results are given to illustrate the WF estimation quality. The possibility of detailed decomposition of the LISN-EMI waveforms is depicted in both time and frequency domains. Comparative analysis of frequency responses for PQRDCLI-link voltage changes is given.

Adaptive estimation of the transformer stray capacitances for DC–DC converter modelling

Abstract: New low cost and accurate estimation method of transformer stray capacitances for wide band DC–DC converter modelling and design is proposed. The Wiener filter (WF) method is applied to estimate the transformer impedance – referred to the selected transformer winding configurations. Laboratory tests are used to adapt the filter, that is to find optimal impedance which minimises mean square error between measured, noise perturbed current and reconstructed current. Transformer transfer function peaks indicate internal LC resonances. Stray capacitances are extracted based on resonant frequencies determination. The method validation is carried out by simulation and experimental analysis, where estimated stray capacitances by WF are compared with measurements of an impedance analyser.

Prediction of ringing frequencies in DC-DC boost converter

Abstract: In the paper ringing phenomena in a DC-DC boost converter is presented. The ringing frequency is calculated using an analytical formula. The necessary wide band models of MOSFET transistor, passive and parasitics are described. The calculation results are verified in simulation and laboratory tests.

Electromagnetic interference frequencies prediction model of flyback converter for snubber design

Abstract: Snubber design for flyback converters usually requires experimental prototype measurements or simulation based on accurate and complex models. In this study simplified circuit modelling of a flyback converter has been described to dimension snubbers in early stage of design process. Simulation based prediction of the transistor and diode ringing frequencies has been validated by measurements in a prototype setup. In that way obtained simulation data enabled fast and precise snubbers dimensioning. Application example has illustrated effectiveness of the proposed methodology by line impedance stabilisation network (LISN) spectra evaluation of the experimental flyback converter resulting from snubbers dimensioning.

Accurate Transient Calorimetric Measurement of Soft-Switching Losses of 10-kV SiC mosfets and Diodes

Abstract: The characterization of soft-switching losses (SSL) of modern high-voltage SiC mosfet s is a difficult but necessary task in order to provide a sound basis for the accurate modeling of converter systems, such as medium-voltage-connected solid-state transformers, where soft-switching techniques are employed to achieve an improved converter efficiency. Switching losses (SL), in general, are typically measured with the well-known double pulse method. In the case of SSL measurements, however, this method is very sensitive to the limited accuracy of the measurement of the current and voltage transients, and thus is unsuitable for the characterization of fast-switching high-voltage mosfet s. This paper presents an accurate and reliable calorimetric method for the determination of SSL using the example of 10-kV SiC mosfet modules. Measured SSL curves are presented for different dc-link voltages and switched currents. Furthermore, a deeper analysis concerning the origin of SSL is performed. With the proposed measurement method, it can be experimentally proven that the largest share of the SSL arises from charging and discharging the output capacitance of the mosfet module and especially of the antiparallel junction barrier Schottky diode.

Effective EMI Filter Design Method for Three-Phase Inverter Based Upon Software Noise Separation

Abstract: This paper presents an electromagnetic interference (EMI) filter design method for a three-phase inverter applied to motor drives. The EMI filter design is based upon the results of software noise-separation method. Therefore, no hardware noise separator is required. Moreover, the presented EMI filter design approach provides systematic design procedure, and therefore, trial-and-error overhead is not required, and thereby, shortening the development time and saving the cost. The presented method determines common-mode choke and differential-mode choke based upon the required impedance to attenuate the noise. A three-phase inverter for inductor motor drives is used as the equipment under test (EUT), and the related conductive EMI filter is designed and verified. It will be shown that EMI filter designed by this systematic design method effectively attenuates the conductive EMI components to meet the requirement of EN 55011.

Modeling of a Buck Converter With a SiC JFET to Predict EMC Conducted Emissions

Abstract: The reduced switching times of silicon carbide (SiC) components compared to Si components in similar conditions are a great advantage from the point of view of efficiency, but, due to the high dv/dt and di/dt, conducted electromagnetic emissions are increased. Therefore, the availability of a method which can predict these emissions is increasingly necessary. To the best of the authors' knowledge, a model that can predict differential mode as well as common mode for a converter including sic devices has not yet been published. the novelty of the work presented here is the integration of different modeling approaches to form a circuit model of a SiC-based buck dc-dc converter working in frequency range from 40 Hz to 30 MHz. A modeling approach of the passive parts of the converter is presented. Then, the model obtained is used in simulations to predict the drain-to-source voltage and the drain current for the JFET. Conducted emissions received by the line impedance stabilization network are also computed. Simulation results are compared to measurements for different duty cycles and different gate resistors in the time and frequency domains. A good agreement is obtained. In the frequency domain, in all cases, differences are less than 5 dBμV up to 30 MHz excepted in the JFET source current.

Ultra-compact and ultra-efficient three-phase PWM rectifier systems for more electric aircraft

Abstract: In order to improve the efficiency and to reduce the environmental impact of aircraft, global efforts for reducing the aircraft weight are under way. One of the key issues thereto is the wide application of electric systems instead of heavy mechanical, pneumatic and hydraulic driven equipment. This change in the power supply structure of an aircraft is known as More Electric Aircraft (MEA). In the course of this concept unidirectional active three-phase rectifiers in the power range of several kW are required, mainly for electrically driven actuators for flight control. In modern civil aircraft a three-phase AC mains with a voltage level of either 115 V or 230 V and a variable mains frequency of 360 Hz . . . 800 Hz exists. In this work unidirectional three-phase rectifiers are evaluated which are able to meet the enhanced requirements of aircraft application. Starting with a brief survey on the power supply structure and the demanding requirements to be met such as the power factor or input current quality, a survey on three-phase rectifier topologies suited for aircraft applications is given. There, also passive and hybrid (active/passive) systems are considered. Based on this evaluation, the two-level three-phase ∆-switch rectifier is found to be an ideal solution for a mains voltage of 115 V and the three-phase three-level Vienna Rectifier topology optimally fits the requirements for a 230 V mains. Initially, the specific characteristics and control approaches of the well known Vienna Rectifier topology are summarized. The MEA concept calls for a minimization of volume and weight and hence a single-objective optimization of the three-phase Vienna Rectifier