Session 6: EMC Risk Management
EMC risk management can mean different things for a variety of EMC engineers. For some, it means reducing design risks for standard compliance, and for others, it means a risk-based approach to ensure EMC. In its extreme end, the risk-based approach can be used to ensure dependability of electric and electronic systems under electromagnetic disturbances (EMD). This is called EM resilience. In this session, different aspects and advances in EMC risk management are discussed.
In this year’s revision, Mr. Tishehzan discusses a topic on argumenting EM resilience of a system. Then, Dr. Gavrilakis discusses a practical implementation of a risk-based EMC approach in railway systems, and finally Mr. Leppäaho talks about the EMC problematic of large high power drive systems and how to apply risk-based approach there.
Session 6, Speaker 1
Application of Assurance Cases in Arguing EM Resilience
Over the last decade, awareness has grown that compliance to EMC standards does not necessarily imply that all properties of a system, such as reliability, safety, and security, are adequately assured when the system is exposed to electromagnetic disturbances. While the application of a risk-based approach and the concept of EM resilience has been proposed to overcome this issue, a methodology to show that the employed new approaches provide compelling arguments and evidence to assure the properties of interest seems to be missing. Recent applications of risk-based EMC have shown that how the lack of robust argumentation method could affect the certification process adversely. In this presentation, the necessity of using structured argumentation for demonstrating the developers claims about system properties while risk-based EMC and EM resilience have been applied, is explored. Then, the application of assurance in demonstrating properties, like safety of systems in the presence of electromagnetic disturbances, by using Goal Structured Notation (GSN) is described. In order to depict the use of this method, the concept 4+1 Principles of EM Risk Management for safety is introduced and explained by GSN. These principles are derived initially from software safety assurance, and they can be seen as an guidance and core of any safety risk management approaches which require to be uphold.
Mohammad Tishehzan is an Early Stage Researcher in the EU-funded MSCA PETER Project, and a PhD student in the department of computer science at the University of York since 2020. He is carrying out research on “Modelling and Reasoning about EMI Interactions in Autonomous and Complex Vessel”. His primary goal is to develop a through-life EMI risk-based modular safety case approach in a form suitable for all of the stakeholders in the marine industry. He completed his B.Sc. and M.Sc. programs in electrical engineering in 2015 and 2019, respectively, from Shahid Beheshti University and AmirKabir University of Technology. He also worked as an EMC test engineer at the EMC type approval laboratory of Amirkabir University for two years before joining the PETER project.
Session 6, Speaker 2
Dr Alex Gavrilakis
EMC Hazard/Risk Analysis Process for Railway Projects, Including a Case Study
This talk will describe in a detailed but simplified manner the process followed by UK railway projects, for the identification and mitigation of potential EMC hazards and risks. A case study of a hypothetical railway project is presented, where the process is shown in a step-by-step manner (i.e. Description of existing infrastructure; Description of changes; Completion of interaction matrix; Identification of potential hazards; Risk assessment & ranking). This process can be adopted by any industry, and it is especially useful when whole systems are considered rather than simple components. Apart from the EMC engineers/consultants, it can also be useful to suppliers as a good EMC Hazard Identification matrix/log can simplify the EMC assurance process for product approval. The benefits of holding hazard workshops for more complex interfaces will also be discussed.
Dr Alex Gavrilakis
Dr. Gavrilakis has been with Network Rail since 2016 as a Senior Design Engineer, specialising on EMC, Earthing, and Bonding, based on the London Waterloo station NR offices.
Before joining NR, he spent 2 years with Atkins as a Senior Systems Engineer, and from 2004 to 2014 he was an engineer with ERA Technology (now RINA). His research topic during his PhD was EMC modelling of screened communication cables.
Currently, Alex’s main technical focus is on the EMC effects of railways traction power and harmonics on railway systems and third-party interfaces.
He is a member of the IET’s professional committees on both Railway and Electromagnetics, and has chaired a number of Rail EMC IET events. He is a Chartered Engineer, IET Mentor, and a Senior Member of IEEE. He has been the author of Network Rail’s Control Period 6 EMC Contractor’s Requirements Technical Module.
Session 6, Speaker 3
EMC Plan for Power Drive Systems (PDS) to Prevent Interference with Other Systems
One way to do cost optimization for high power drive systems is to relax the compliance requirements of drives used in the system with radio frequency emission limits set out for typical commercial and light industrial devices. This approach is highlighted in the international power drive systems’ EMC standard IEC 61800-3 that specifies relaxed emission limits with a mandate to create an EMC plan for the installation in case the relaxed limits are used. This risk-based approach is used to avoid costly filter installations on megawatt-scale systems, but also on smaller systems with special power grids, like an IT grid. This presentation discusses the motivation of the relaxed limits from a system cost point of view with some examples, and outlines the steps needed to comply with the standard. They range from a simple distancing approach to more complex system designs, where all filtering and shielding structures are carefully engineered to fit the system. Some of the steps for proper system compliance need new risk management means that are not well known for EMC engineers. These risk management means were further developed during an EU-funded MSCA project PETER. This presentation shows their application to the problematic of high power drive system installations.
Oskari completed his B.Sc. (2014) and M.Sc. (2015) degrees from Tampere University of Technology (currently Tampere University) in Electrophysics. He also spent an exchange semester in 2013 at FAU Erlangen, mainly at Lehrstuhl für Elektromagnetische Felder. He is about to defend his Ph. D. degree in spring 2023. He has been a Main Circuit Development Engineer since 2013 at Vacon Oy, Finland, which became part of Danfoss in 2014 with a short stint at Valeo in between 2020-2022 during his doctoral studies. Currently, he is a Development Engineer at Danfoss Drives, Finland.
He stumbled upon EMC early in his Master's studies, when he was searching for an interesting subject that would combine physics and electronics that were his main interests during Bachelor studies. During his early career, he contributed to EMC design of Vacon 100 AC Drives and was in charge of the EMC design for some of the models. Later, he got more responsibility outside EMC at Danfoss Drives, moved into the USA for a few years, and participated in various design tasks on a yet-to-be-released product line. After spending some time in the US, it was time for him to come back to Europe to embark a Ph.D. degree in an EU-funded MSCA project PETER. In January 2023, he has returned to Danfoss Drives.
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