Tutorial

 

Rm. 302b / 14:00-17:00, Sunday, June 4
Power Electronics Circuits as Front End of Grids Supplied by Environmental Friendly Sources of Energy

Prof. Adrian Ioinovici

IEEE Fellow
Holon Institute of Technology
Israel
Adrian Ioinovici , author of hundreds of papers about power electronics circuits and a recent book "Power electronics and energy conversion systems", Wiley Inc., is a world authority in the domain. He pioneered the development of the switched-capacitor converters and inverters in the last decade of the XX-th century. In the last years, he initiated the concept of hybrid large dc gain converters based on switched-capacitor-inductor cells that found the use in applications related to the grids supplied by green sources of energy or in electrical vehicles.
Dr. Kerui Li

Aalborg University
Denmark
Kerui Li received the B.S. degree from South China University of Technology, Guangzhou, China and the M.S. degree from Sun Yat-sen University, Guangzhou, China, in 2013 and 2016, respectively. He is currently working in the Department of Energy Technology, Aalborg University, Aalborg, Denmark. His research interests are focused on DC-DC converters for renewable energy application.
ABSTRACT
The last decade saw a rapid development of the environmental-friendly sources of energy with the purpose to reduce the world dependency on the classical polluting and depletable resources of energy. However, the renewable power generation units are variable in nature: the output of a solar cell varies with the insolation, that of a wind cell with the weather , that of a fuel cell with the age or chemistry conditions. For being useful as front-end of the electrical grid, the voltage generated by the renewable sources has to be stabilized, as the customers are highly dependent on uninterruptible, high quality power supply. The voltage supplied by the green energy sources is also too low to be used as such. Even in grid connected applications, multiple series-parallel PV arrays for increasing the voltage are not always chosen due to safety issues, parasitic capacitance effects and module mismatch. And in local microgrids, isolated solar cells are preferred. The implication is that each cell has to be followed by a converter able to step-up the voltage by several times.

It is highly required for the power electronics circuit to absorb a non-pulsating current in order to prolong the life of the clean source of energy. In hybrid electric vehicles, low voltages of 14 V or 42 V from batteries or fuel cells have to be raised to hundreds of volts.

Data and telecommunications applications use a 400 V dc distribution system, converters able to raise the standard backing battery 48 V to 400 V being necessary.

The above and many other applications require dc-dc converters and dc-ac inverters with special features: a very high dc gain, a very high efficiency, as it is not conceivable to waste a considerable part of the new created energy only during its processing, a good power density due to a small components count, a non-pulsating input current, an affordable cost.

The research in the last years focused on the development of solutions to answer the above requirements. More than two hundreds papers have been published in this subject. It is the time to present these solutions in a comparative manner in order to help the industry engineers to understand them and choose the best ones depending on their suitability to actual applications. A systematic way for deriving such converters will be also presented in order to facilitate to the researchers and graduate students the development of novel power electronics in agreement with new requirements that the green energy industry will put in the future.