Dr Sasa Djokic received Dipl.-Ing. and M. Sc. degrees in Electrical Engineering from the University of Nis, Nis, Serbia, and Ph. D. degree in the same area from the University of Manchester Institute of Science and Technology (UMIST), Manchester, United Kingdom. He is currently a Reader in Electrical Power Systems at the University of Edinburgh, Scotland, United Kingdom, where he is teaching undergraduate and graduate (master and doctoral level) classes on Fundamentals of Electrical Engineering, Electrical Power Engineering, Power Systems, Electrical Machines, Power Systems Economics, Network Integration of Renewable Generation and Power Quality.
Dr Djokic has published around 250 papers, of which several have received IEEE Best Paper and Best Poster awards. Over the past 25 years, Dr Djokic has performed research in the areas of theoretical electromagnetics, illuminating engineering, several aspects of power quality analysis, load and microgeneration modelling, assessment of solar and offshore/onshore wind energy resources and, most recently, power system reliability and security analysis.
Dr Djokic is a recognized expert by IEC and has contributed to the several national and international standards, technical reports and engineering recommendations. He continues to be active in a number of ongoing CIGRE/CIRED, IEEE, IESNA, IEC/CISPR and other international Working Groups, Task Forces and Committees.
Sasa Z. Djokic and Zafar Iqbal
"Non-Fourier Fundamental Components for the Mitigation of Waveform Distortions"
Abstract – Fourier-based fundamental component is a typical target for the mitigation of voltage and current waveform distortion, where either passive or active filters are used for the cancellation of harmonics obtained from the Fourier Transform (FT) decomposition. Using a few examples of common rectifier power electronic loads, this paper demonstrates that there are alternatives to the FT-based harmonic mitigation, where the mitigated target fundamental components are different from the Fourier-based fundamental component. The discussed non-Fourier fundamental components include: equivalent energy content fundamental, equivalent active and reactive power fundamentals and half-wave equivalent fundamentals, which are all based on the evaluation of energy and power flows from the purely sinusoidal or distorted power supply system to the connected rectifier loads, taking into account losses on the source impedance.
In 1980 Eckhard Thal graduated the Moscow Power Engineering Institute. Same year he joined ELPRO Berlin as design engineer in the inverter development. In 1991 he received his PhD in the field of power electronics at the Chemnitz University. Since 1991 he is working for Mitsubishi Electric Europe (Ratingen/Germany) in application engineering for power semiconductors.
Abstract – The key milestones of Mitsubishi Electric’s more than 20 years R&D activities in the field of power SiC-technology will be reviewed. The latest achievements of high current SiC-modules with 1200V, 3300V and 6500V blocking capability will be presented. Based on practical application examples the benefits of using high power SiC-modules will be explored. Finally an outlook on Mitsubishi Electric’s development roadmap for high power SiC-modules will be given.
Abstract – The paper presents a new, indirect method of measurement, for determining the characteristics of the regulation of synchronous machines with salient poles. The method is based on the measurement results in the no-load and short circuit conditions. The difference in comparison to the existing similar methods is, according to the authors, in determining the characteristics of regulation at different loads in the original way. This method takes into account the influence of the change in the flux leakage of the field windings depending on the excitation currents in the original way. This leads to the fact that, according to the proposed procedure, the indirectly obtained regulation characteristics will be much more accurate and reliable compared to the results obtained by the previous similar indirect procedures.
Dr. Ki-Bum Park received B.S., M.S., and Ph.D. degrees in electrical engineering from the Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea, in 2003, 2005, and 2010, respectively.
He worked as a Researcher with KAIST in 2010, focusing on Si/SiC-based high frequency power electronic converters. He is currently with ABB Corporate Research Center, Switzerland, as a Senior Scientist. His current research interests include power conversion system for EV charging infrastructure, grid integration of renewables, and application of wide bandgap semiconductor (SiC and GaN) in association with system-level optimization of power electronics. He has published more than 80 papers including one third in peer-reviewed journals.
Spread Spectrum Modulation for LCL Grid-Tied Converter
Abstract – LCL filter is often the bulkiest and heaviest component in grid-tied converters, which is designed to satisfy the grid harmonic standards such as IEEE519. To reduce the filter requirement, application of the spread spectrum modulation (SSM) to grid-tied converters is investigated in this paper. LCL filter design methodology for SSM is presented and comparative analysis between the conventional pulse-width modulation (PWM) and SSM is carried out focusing on their impacts on LCL filter parameters.