EPE 2018 ECCE Europe – Riga, Latvia, 17-21 September 2018 ________________________________________________________________________

EPE guidelines for tutorials 1

RELIABILITY OF PV SYSTEMS - FROM BASIC THEORY TO PRACTICAL EXPERIENCES

Frede Blaabjerg Aalborg University, Faculty of Engineering and Science, Aalborg, Denmark. Boris Dumnic, Dragan Milicevic, Vladimir Katic and Bane Popadic, University of Novi Sad, Faculty of Technical Sciences, Novi Sad, Serbia. SCOPE AND BENEFITS The aim of the tutorial is to serve as a comprehensive guide to the most influential performance factor of the photovoltaic technology – the reliability. The tutorial will offer researchers, students and professionals, within the respective field, the possibility to comprehend the main challenges and the principles behind the design for reliability in power electronics. Additionally, the lecturers will use their accumulated experience to provide the audience with the practical knowledge in fault detection, fault manifestation and root cause analysis. This should greatly improve the competences of the professionals (and future professionals) working in the field of power electronics and photovoltaic R&D sector and PV operation and maintenance sector. CONTENTS Renewable energy sources (RES), by their very nature, represent the corner stone of the modern notion - sustainable development. One of the leaders in renewable energy market currently is the photovoltaic (PV) energy conversion technology. The increased share of PV systems in the worldwide energy consumption has significant positive influence in regard to energy security and environmental concerns. However, it is currently hard to conceive a functional RES (and therefore PV) system without a considerable amount of different power electronics devices. Therefore, the notion of reliable PV system faces similar challenges as power electronic devices in highly efficient generation and conversion of electrical energy. Furthermore, several key requirements and constraints need to be imposed on power electronic converters in emerging applications. Key requirements will influence the five basic performance factors – cost, efficiency, power density, reliability and manufacturability. The most significant influence on the safety, service quality, lifetime, availability and life cycle-cost of the specific (PV) system will be achieved by the reliability improvement. This tutorial will aim at presenting a comprehensive study to solar energy, covering the basic ideas behind the operating principles, main components and classification of PV systems. During the tutorial, the audience will be introduced to main reliability challenges and will have a chance to learn the principle behind the design for reliability in power electronics. Building on the acquired knowledge, the reliability of power electronic devices in PV applications will be discussed using the appropriate case study examples. Lecturers will use their field experience in design, installation, operation and maintenance (O&M) of several PV power plants with various power levels in order to provide the audience with practical

EPE 2018 ECCE Europe – Riga, Latvia, 17-21 September 2018 ________________________________________________________________________

EPE guidelines for tutorials 2

knowledge concerning faults detection and root cause analysis. A detailed classification of the PV systems faults, based on the origin, type and impact will be given. Using the lecturers accumulated experience, a comprehensive guide on root causes and fault manifestation will be presented. A structured approach in failure root cause analysis, allowed experts not only to fix the problem but to accumulate substantial knowledge and offer the audience within this tutorial the suggestions for reliability improvement in PV systems. Schedule is as follows: Monday, 17 September 2018 - Tutorial day (Location: RTU, Riga, Latvia) 08:00 - 09:30 Registration 09:30 - 10:00 Introduction to solar energy:

a. Solar energy potential and performance indices. 10:00 - 10:45 Overview of PV systems - types and main components – from

module inverter to PV farms: a. Photovoltaic power plant operating principles, b. Main elements of the photovoltaic system, c. Classification of photovoltaic power plants.

10:45 - 11:00 Coffee break 11:00 - 12:00 Reliability challenges in power electronics:

a. Towards reliable power electronics, b. Motivations, field experiences and challenges, c. Ongoing paradigm shift in reliability research applied to

PV systems, d. Concepts of FMEA and applied to PV systems.

12:00 - 13:00 Design for reliability in power electronic systems: a. Design for reliability concept, b. Introduction to reliability basics, c. Reliability basics, Weibull distribution, Failure rates, Bx

lifetime, Reliability block diagrams, d. Faults in PV systems and components degradation. Main

elements of the photovoltaic system, 13:00 - 14:00 Lunch break 14:00 - 14:45 Reliability of power conversion systems in PV applications - case

studies: a. Mission profiles in PV systems b. Reliability prediction of power electronic converters c. Six-step system-level reliability prediction approach for

photovoltaic systems d. Design for Reliability and Robust (DfR2) tool platform for

case studies (Micro-inverter and string inverter)Introduction to reliability basics,

14:45 - 16:15 Field experience from different PV systems; small scale and large scale – where are the faults:

EPE 2018 ECCE Europe – Riga, Latvia, 17-21 September 2018 ________________________________________________________________________

EPE guidelines for tutorials 3

a. Roof-top PV power system 8 kW, b. String inverter based 536 kW PV power plant, c. Central inverter based 2 MW PV power.

16:15 - 16:30 Coffee break 16:30 - 17:00 How to improve the reliability of PV systems 17:00 - 17:30 Summary and Q&A WHO SHOULD ATTEND The topic of power electronics components reliability, including the design for reliability, is interesting for a broad audience. Among other things, the tutorial offers practical experiences in fault analysis and applicable suggestions for reliability improvement. Expected audience should include individuals in following areas:

Ø Researchers, Master and PhD students in the area of power electronics reliability and renewable energy sector,

Ø Engineers from R&D sector in the area of power electronics and PV systems, Ø Industrial engineers in the related sectors.

The tutorial is well adapted to satisfy the need of all interested parties coming from different technical backgrounds. However, some parts of the tutorial could require a background in electrical engineering. Technical Level: intermediate ABOUT THE INSTRUCTORS

Frede Blaabjerg is currently a Professor with the Department of Energy Technology and the Director of Center of Reliable Power Electronics (CORPE), Aalborg University, Denmark. He has intensive research work on power electronics and its applications in motor drives, wind turbines, PV systems, harmonics, and the reliability of power electronic systems. He has held more than 300 lectures national and international, most of them in the last decade are invited and as keynotes at conferences, covering various topics on power electronics, including the reliability. He has contributed more than 450 journal papers. Among other awards, Dr. Blaabjerg received the IEEE William E. Newell Power Electronics Award in 2014.

Boris Dumnic is currently Associate Professor with the Faculty of Technical Sciences, University of Novi Sad, Serbia. He is appointed for director of Faculty Centre - Centre for Renewable Energy Sources and Power Quality (CRESPQ) on 2010. From 2015 he is Director of Department for Power, Electronics and Telecommunications Engineering. The focus of his current research is on Electrical Machines and Drives, Renewable Energy and Power Electronics. He is IEEE Member and vice-chair of IEEE Serbia and Montenegro Section.

EPE 2018 ECCE Europe – Riga, Latvia, 17-21 September 2018 ________________________________________________________________________

EPE guidelines for tutorials 4

Dragan Milicevic received his Ph.D. degree from the University of Novi Sad, Serbia. Since 2004 he has been working at the, Faculty of Technical Sciences, Department for Power, Electronics and Telecommunications Engineering - DEET, Novi Sad, Serbia. He was promoted to the rank of Associate Prof. in 2014. His main research interests are in the area of control, modeling and simulation of renewable energy resources and multiphase electric drives and.

Vladimir A. Katic (IEEE SM 2000, M´92, S´90, EPE Member) is currently Professor at the University of Novi Sad, Serbia, Vice-Dean of the Faculty of Technical Sciences and Chairman of the Power Electronics and Converters Group. He is the chair of the Int. Symposium on Power Electronics, sited in Novi Sad, guest/associated editor or reviewer of many scientific journals, grant holder or participant in 50+ scientific projects, and author/co-author of 22 textbooks. He has contributed to more than 300 international journal and conference papers, also. The main areas of scientific interest and research of Prof. Katić are power electronics converters (grid-integrated), electric power quality, renewable energy sources (solar and wind) and electric vehicles´ drive and charging infrastructure.

Bane Popadic recieved B.Sc. and M.Sc. degrees in Electrical engineering at the University of Novi Sad, Novi Sad, Serbia, in 2011 and 2012 respectively. Since 2012 he is persuing Ph.D. degree at the Faculty of Technical Sciences, University of Novi Sad. His interest area includes grid integration of renewable energy sources and electrical drive control. He is a student member of the IEEE.