Contact micro-welding is an effective technology used to reliably connect miniature parts in precision instrumentation and in the manufacture of electronic components and circuits. The quality of welded structures directly depends on the power source and the ability to control its parameters.

Kyiv Polytechnic is rightfully proud that the formation of domestic welding production began here. For almost a century, Igor Sikorsky Kyiv Polytechnic Institute has been creating and improving welding technologies and welding materials with specified properties, designing equipment, diagnosing and predicting the reliability of welded structures, etc.

It is quite obvious that a condition for ensuring high quality welded joints is a controlled supply of energy to the welding zone. Therefore, the role of the welding machine power supply is very important, as it must be able to control and regulate the welding current, the voltage at the welded contact, the load power, or several of these parameters simultaneously. Yulia Kozhushko, an assistant professor at the Department of Electronic Devices and Systems of the Faculty of Electronics, is working on the improvement of energy converters for pulsed-load systems.

Let's get acquainted. The interlocutor is not only beautiful and intelligent, but also friendly and sincere. She tells us that she came to study at Kyiv Polytechnic in 2011, and in 2017 she received a professional qualification as an electronic engineer. Igor Sikorsky Kyiv Polytechnic Institute provides ample opportunities for young professionals, so the researcher continued to improve her knowledge and skills at the university's graduate school. Soon, in 2021, she received her PhD in the specialty 171 "Electronics", having defended her dissertation "Electricity converters of hybrid capacitive drives for systems with pulsed load". Using the example of energy consumption during resistance micro-welding, Yulia proved that the use of hybrid capacitive energy storage devices based on batteries and supercapacitors for autonomous power supply systems and portable devices is a promising area of research. "Currently, the scientist is working on improving the converter circuit for distributing energy between capacitive energy storage devices, which allows expanding the functionality of such storage devices in case of high-power pulse power consumption," says Professor Yevhen Verbytskyi, Head of the EPS Department.

Among other things, Yuliia Kozhushko is actively involved in the international activities of the department, was a participant in the Erasmus+ credit mobility program at the University of Zagreb, Croatia (2018-2019) and did a research internship at the University of Lorraine, France (2020-2021), where she conducted experimental research on the topic of her dissertation under the supervision of Associate Professor Oleksandr Bondarenko, who initiated the cooperation and contributed to the project in every possible way.

It is worth noting that the researcher is the author of 7 scientific articles (5 of which are in professional publications in Ukraine and 4 are included in the Web of Science and Scopus databases) and 13 abstracts at national and international conferences. During her postgraduate studies, the young scientist was one of the performers of the department's research works on the following topics: DB №0116U006924 "Improving energy efficiency and resource saving by means of power electronics for the technology of obtaining highly reliable welded joints of dissimilar materials"; DB №0119U100189 "Scientific and technical principles of creating devices for resistance welding of biological tissues by DC pulses"; DB №0120U101285 "Energy-efficient systems for fast charging of combined capacitive energy storage devices such as supercapacitor-battery".

In addition, in 2021, Yulia and her colleagues won the National Academy of Sciences of Ukraine Prize for Young Scientists for their work "Development of the theory of building power sources with a modular structure and intermediate energy storage for resistance welding." In 2020-2022, she worked as a junior researcher at the Research Institute of Electronics and Microsystems Engineering, which develops and implements modern electronic equipment for industry, energy, communications and medicine and collaborates with leading institutes of the National Academy of Sciences of Ukraine. As a result of her work, she won the university competition "Young Lecturer-Researcher 2022". "The young scientist continues her research on capacitive storage converters for micro- and nano-grids of direct current and brings theoretical results to practical application," concludes the head of the department.

Nadiia Libert