Session 6: EMC Risk Management

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. 

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.

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.