SS18 Challenges and demands of technologies for renewable installations and environmental impact

ABSTRACT

Large centralized power plants continue to play a role in providing alternating current (AC) power to the wholesale power grid; however, there is growing momentum at the medium voltage (MV) level to diversify power offerings and pursue hybrid solutions that incorporate more direct current (DC). Given significant political and stakeholder support for inverter-based native DC power sources, such as solar PV and battery storage, utilities and solutions providers seek to reduce DC-AC-DC conversion losses.
Today, HVDC systems of different suppliers are not interoperable: a converter station of vendor A can’t be connected to a converter station of vendor B as they use different proprietary specifications and standards.
To enable large-scale exploitation of offshore wind energy, there is a need to unlock the interoperability of multi-vendor, multi-terminal and multi-purpose HVDC systems with grid forming control capability. To achieve these goals, some important issues of converter control and current protection will be addressed.
The lecture also contains a description of the main trends (new materials, approaches, concepts) in designing and operating components (voltage transformers, switches, etc.) at the transmission and distribution levels of the power grid, especially related to renewables and energy storage applications. After that the review upon the different profile needs in the industry is presented (ranging from simulation engineers to arc physicists), especially considering the systemic transformation that the power sector has been and will be experiencing in light of renewable penetration.
This lecture will also present topics of new insulating materials for power transformers, in terms of compatibility, high performance properties, resilience for operation in stressed conditions (high temperatures, electrical stresses, transient, DC applications). Recycling of conventional materials will be briefly presented, as one part of the Green deal objectives to decrease power transformers carbon footprint. New products are intensively being launched on the market and applied. More thermally upgraded papers are used, including Aramid insulation, but testing techniques are not yet developed and standardized. This is important task of R&I community.
Finally, the topic of human exposure to electromagnetic fields will also be addressed. The main provisions of the legislation related to exposure of the general public and workers to electromagnetic field will be presented. The results of electromagnetic field measurements and the field levels that usually occur in the vicinity of the most relevant sources (overhead power lines, cable lines, substations) will be given. Different methods for electric and magnetic field mitigation, that could be applied in the case when the field levels exceed the prescribed reference levels will also be explained and demonstrated on practical cases.

The list of presentations follows: (1) Medium Voltage DC Technologies Bring New Opportunities for Renewable Installations and Energy Storage Facilities, Slobodan N. Vukosavić, SANU, ETF (20 minutes) (2) Enabling Interoperability of Multi-Vendor HVDC Grids, Aleksandra Lekić, TU Delft (20 minutes) (3) Transmission & Distribution equipment trends in Energy Transition, Nenad Uzelac, G&W Electric Company (20 minutes) (4) Challenges and demands in perfomarnce of modern insulating materials for power transformers of today and tomorow, Jelena Lukic, EEINT (15 minutes) (5) Exposure of people to electromagnetic fields: legislation, levels and mitigation techniques, Maja Grbic, EEINT (15 minutes).

CHAIR

Maja Grbić, Electrical Engineering Institute Nikola Tesla

SPEAKERS

Aleksandra Lekić, TU Delft
Nenad Uzelac, G&W Electric Company
Jelena Lukić, Electrical Engineering Institute Nikola Tesla
Maja Grbić, Electrical Engineering Institute Nikola Tesla

SHORT BIO

	Aleksandra Lekić received the B.S., M.S., and Ph.D. degrees in Electrical Engineering from the School of Electrical Engineering, University of Belgrade, Belgrade, Serbia, in 2012, 2013, and 2017, respectively. Between 2012 and 2018 she has been a Teaching Assistant with the School of Electrical Engineering, University of Belgrade, and an Assistant Professor from 2018 to 2019. In 2019 she worked as a Postdoctoral Researcher at the Department of Electrical Engineering ESAT – ELECTA, KU Leuven and in the Institute EnergyVille, Genk, Belgium.
	Nenad Uzelac EDUCATION: Masters of Science in Product Development Northwestern University, Evanston, Illinois, 2004 Masters of Science in Power Engineering. University of Belgrade (Serbia), 1995 Continuing Education – New Product Development Management, Finite Element Analysis, Switchgear design and testing, Switchgear condition assessment, New Technologies PROFESSIONAL SUMMARY: 20 years of experience in medium voltage switchgear design, testing and production implementation, with focus on reclosers and automation. Actively participates in IEEE and CIGRE working groups and standard activities. Chair of IEEE Switchgear Technology & Innovation subcommittee. Chair of CIGRE A3 Study committee (Transmission and Distribution equipment). Research interest include electrical and magnetic field analysis, MV switchgear design, development and testing, new product development process optimization, non-intrusive condition assessment and internal fault studies. EMPLOYMENT: G&W Electric Company:2015 – Present (Global research and standards director) Responsible for global technology development from ideation to proof of concept. G&W Electric Company – 2006 to 2015 (Switchgear R&D Leader) Responsible for new product development in switchgear department – design, testing and production implementation of SF6 and solid dielectric medium voltage switchgear equipment up to 38kV and 25kA. Provide direct supervision and coordination of the activities of R&D team. Conduct research studies on project related activities, like numerical analysis of the pressure rise during the internal faults in SF6 switchgear. Leads feasibility studies for new development switchgear projects. Champion the change of the New Product Development process. G&W Electric Company – 1999 – 2006 – (Project Engineer) Highlights: Part of the design team on 3 phase SF6 medium voltage recloser – responsible for the magnetic actuator and interface electronics design. Project leader in development of 3 phase single/triple solid dielectric medium voltage recloser, responsible for the design and product implementation. Technical lead in development of 8 cycle transfer SF6 switch that utilizes mirror bit communication. Institute “Nikola Tesla”, Serbia – 1995 – 1998 – Research Engineer Participated in development and testing of the analog and digital controllers for power generating plants. Tested and troubleshooted rectifiers and UPSs systems in power utilities.
	Jelena Lukic was born in Belgrade, Serbia in April 1970. She received her BSc in 1996, the MSc degree in 2004 and PhD degree in 2013. She has been employed in Electrical Engineering institute Nikola Tesla, Belgrade, Serbia from 1996, holding position of head of specialized laboratory for oil and paper insulation testing, accredited according to ISO 17025 from 2004. Her fields of expertise are insulating oil and paper analyses, power transformers condition and risk assessment, know-how in PCB removal, corrosive and aged oils re-refining (holds two registered patents related to transformer oil treatments). She has published more than 80 papers, 9 in peer review papers and 10 papers as invited lecturer at international conferences worldwide. She has been a project leader of more than 20 research projects with the industry in country and abroad, related to insulation systems for power transformers, including high level of participation in CIGRE and IEC TC 10 WG’s. She was convener of CIGRE WG A2.40, IEC TC 10 AhG 40 and is currently convener of CIGRE WG D1.76. Jelena Lukic is delegate of Serbian National Committee in International Electrotechnical Committee Technical Committee 10 (IEC TC 10) – Fluids for Electrotechnical Applications, Serbia NC Representative in CIGRE SC A2-Transformers and IEC TC 10 Liaison Co-officer of CIGRE SC A2.
	Maja Grbić is a research associate at Electrical Engineering Institute Nikola Tesla, University of Belgrade, Serbia. She received BSc, MSc and PhD degree in electrical engineering in 2010, 2012 and 2021, respectively, from School of Electrical Engineering, University of Belgrade. Since 2010 she has been employed at Electrical Engineering Institute Nikola Tesla, at the Power Facilities Department. Her primary field of interest has been research in the area of electromagnetic fields. She has participated in 14 major projects, 7 times as the head of the project. She has been involved in 46 expert evaluation studies regarding influence of new/reconstructed electromagnetic field sources on the environment, primarily as the head of the study, as well as in 18 studies related to electromagnetic fields and electromagnetic interference and over 1000 reports primarily referring to electromagnetic field testing. In 2018 she has been appointed head of the Laboratory for electromagnetic field testing, which is accredited in accordance with ISO/IEC 17025 standard. She has published 67 papers at national and international journals and conference proceedings. She was awarded by the Belgrade Chamber of Commerce for the best master’s thesis and by the Serbian Chamber of Commerce for the best PhD thesis.