We have all been asked to switch off our mobile phones or tablets on airplanes. Most of us comply without really understanding why this is required. While electronic devices offer numerous benefits, they can also generate certain levels of electromagnetic interference (EMI). Electrical currents, which create electromagnetic waves, can create disturbances at any frequency range (Hz to GHz). When this happens, electronic devices, electric vehicles and even power grid systems can malfunction or stop working. For example, electromagnetic waves – also called emissions – from laptops or smartphones could interfere with an aircraft‘s electronic systems.
As many countries around the world adopt measures to encourage the use of electric vehicles (EVs) as a way to reduce their carbon emissions, the interconnected electrical systems of EVs, notably for drivetrain functions, power conversion, wireless internet connectivity and driver assistance can be particularly susceptible to electromagnetic disturbances. In a society that is becoming increasingly all-electric, attention to electromagnetic compatibility (EMC) is growing and so is the need for related test requirements and standards.
Electric, connected and smart mobility
Global demand for uninterrupted fast connectivity, environmentally friendly mobility and alternative power options such as solar panel systems is high. By 2028, smartphone subscriptions could rise to approximately 8 billion worldwide compared to 6,5 billion in 2022, according to a report published by Statista. Solar panels are mushrooming everywhere as renewable energy systems become a viable alternative to fossil fuel-based power systems. Electric and autonomous vehicles are changing mobility aspirations. A 2023 report of the International Energy Agency (IEA) showed EVs accounted for around 18% of all cars sold compared to 14% in 2022. Battery-powered electric cars, which plug into the grid to recharge, totalled 70% of all EVs sold. With an increasing number of charging stations, electrical grids will have to be able to manage this increased demand for power and also be able to function without EMI.
The need for EMC standards
IEC International Standards specify the general conditions and rules necessary for achieving EMC, which is the process in which electromagnetic disturbances are contained so that all surrounding equipment can operate safely and reliably. These standards describe electromagnetic emission measurement methods, set emission limits, detail immunity testing techniques and test levels, and recommend mitigation methods to limit the effect of electromagnetic disturbances. They set essential requirements for smart grids and many other electrical and electronical devices, from EVs to solar panels.
Standards prepared by IEC Technical Committee 77: Electromagnetic compatibility, and its subcommittees (SCs), help to ensure equipment, electronic systems and services do not suffer from electromagnetic disturbances. The IEC 61000 series describes EM phenomena and the EM environment. These standards are widely used by industry and are equally referred to by other international and regional standardization organizations. Governments the world over use them as a basis for regulation, an example being the European Council Directive on Electromagnetic Compatibility.
The IEC also takes part in the International Special Committee on Radio Interference (CISPR), which prepares standards dealing with the EM emissions of products. Bettina Funk is the Chair of CISPR and she explains the two different scopes. “There are two broad areas for EMC work: emissions, i.e. the product emitting EM waves, and immunity, which is the ability of a product to work even though EM waves are in its environment. When TC 77 was founded inside the IEC, it was mostly involved with the immunity side of things and grid interference. CISPR deals mostly with the emissions aspects. As always, reality is a little more complex than this black and white description, and TC 77 and CISPR work together quite closely and will have to more and more, notably as we move towards increasing off-grid electrification.”
Protecting people
Also relevant to EMI is TC 106, which prepares standards used for the assessment of human exposure to EM fields by the wireless and mobile industries, broadcasting authorities, regulators and government agencies, as well as the automotive and electrical power sectors. This includes the compliance assessment for all mobile phones, tablets, wireless devices, Internet of Things (IoT) and Wi-Fi devices, in addition to the wireless networks and electric power distribution, including wireless power transfer and EVs.
In collaboration with the Institute of Electrical and Electronic Engineers (IEEE), TC 106 published new advanced EM frequency (EMF) testing methods for the latest 5G mmWave technology and devices, and recently achieved 100% approval on the latest base station EMF testing methods focusing on advanced 5G network assessments.
IEC Guide 107, published by the IEC advisory committee on EMC (ACEC), provides key information on drafting publications which deal with the topic. EMC testing and certification for products are also included in the IECEE (the IEC System of Conformity Assessment Schemes for Electrotechnical Equipment and Components) services.
Klaus-Peter Bretz, secretary of TC 77, on EMC standardization
What are the new technologies being addressed by TC 77?
K-PB: They include 5G communication technologies, wireless power transfer (WPT) for EVs, as well as power line communications and radar systems for autonomous vehicles. Existing test methods and requirements will be extended to take new electromagnetic influences into account. (For more on wireless power transfer, read: https://www.iec.ch/basecamp/new-age-mobility).
What are the challenges for standardization?
K-PB: One of them is the voltage fluctuations in public power supply networks. They can be caused by charging stations for EVs, but also other equipment. Publications developed by one of our subcommittees (SC 77A) contribute to the stability of these networks and their power quality. Another challenge is the increasing use of switching power supplies, WPT technologies, radio communication modules in devices and systems – all of which lead to EMI in frequency ranges which were previously of minor interest. These include frequencies between 9 kHz and 150 kHz and frequencies above 6 GHz, which we now must consider. The expected operation of direct current (DC) high voltage networks will also be an issue. Finally, one of our SC’s (SC 77C) future work will address increased portability and the growing strength of geomagnetic storms, which could be due to climate change.
Some manufacturers see EMC redesigns as an extra cost. How could this perception be changed?
K-PB: The role and importance of EMC should be continuously communicated. It is in the interest of manufacturers to develop and market reliable products. Also, an equipment and system may function well now but that is not certain in the future if changes occur in the electromagnetic environment.
How important is cooperation in your field of work?
K-PB: A coordinated approach is required to achieve EMC standardization goals. We exchange information with other relevant IEC product TCs, CISPR, ACEC, the IEC Advisory Committee on Safety (ACOS) and ISO. With the continuous development of new and more advanced technologies, I expect to see EMC requirements and standards that are user-friendly gain even greater worldwide importance to ensure electrotechnical technologies function safely and reliably.
Klaus-Peter Bretz has worked with the IEC German National Committee and CENELEC where he became responsible for EMC standardization and human exposure to electromagnetic fields. He held several positions in CISPR and is a member of several CISPR working groups. In 2012, he was appointed Secretary of TC 77. He now works as an expert in the TC.
This story was originally featured in e-tech magazine published by IEC, and is reproduced here with their kind permission. The original version can be found here