Simulation as a driver of EMI-EMC compliance testing

With increasing electronic content in vehicles, it is imperative for automotive companies to ensure electro-magnetic interference (EMI) and electro-magnetic compatibility (EMC) compliance of various sub-systems in their products.

With simulations, OEMs can improve their EMI/EMC testing processes by identifying potential compliance issues before prototyping, thereby shortening the design development cycle, understanding EMC exposure at the component and vehicle levels, and reducing costly on-road measurements. Engineers can save time and money by using virtual testing to ensure that their vehicles meet EMI/EMC requirements.

Autocar Professional in association with Dassault Systèmes, hosted a virtual masterclass on 'Virtual EMC Design with CST Studio Suite', on August 22, where during his presentation on the subject, Dr Siva Sai Krishna Puranam, Industry Process Consultant at Dassault Systèmes, said, "One needs to meet the EMI/EMC standards when designing a two- or four-wheeler, and engineers must also ensure that the device having human interactions will be safe to use for repeated, prolonged durations."

Dr Puranam who earned his PhD in electrical engineering from the University of Minnesota, USA, specialises in antenna design. He formerly worked for Seagate Technology as an electrical engineer, analysing and validating electronic circuits used in hard disc drives. He is an expert in the fields of antenna array design, simulation, and construction, as well as electromagnetics.

Through his detailed presentation on EMI-EMC design, Dr Puranam explained that EMC simulations early in the design process can help provide answers to the fundamental ‘what-if’ questions to engineers. The presentation also talked about cable and wire harness design, and noted that the simulations can also deliver outputs not accessible by measurements and can be performed without a prototype. EMI-EMC simulations will also help trace electronics emissions, including conducted, radiated, shielded, and emissions from cables.

EMC, which stands for electromagnetic compatibility, is the ability of electronic devices to work together without interfering with each other. Emission refers to the electromagnetic energy that a device produces, while susceptibility refers to the ability of a device to withstand electromagnetic interference.

The development should be seen in the context of the growing number of electronic components in automobiles, in areas such as the powertrain, infotainment, chassis systems, and numerous safety-related functions, which necessitate a virtual pre-compliance EMC test. Therefore, performing a virtual pre-compliance EMC test  during the design phase remains crucial to ensure that emission and susceptibility limits are met early in the product development process, thereby saving time and money for companies.

According to Dr Puranam, the electromagnetic simulation gives engineers a detailed view of all EMC-relevant aspects of a device, from the flow of currents across a circuit board to the propagation of fields between co-site antennas, and helps them identify and resolve potential problems before testing. This not only cuts development time and costs but can also reduce the risk of failing regulatory EMC testing. 

Regulations ensure that devices must not emit electromagnetic fields that can disrupt other electronics and must be able to withstand interference from nearby devices and from environmental electromagnetic effects (E3) such as lightning strikes or electromagnetic pulses. 

Several Indian OEMs including some of the biggest transportation and mobility players in the country, have deployed Dassault Systèmes' Simulia family of applications to drive innovation and efficiency through digital simulation for all existing electric vehicle (EV) models in their portfolio.

An Indian-origin carmaker also deployed the  Simulia CST Suite applications at its R&D centre. The company is leveraging simulations to meet safety regulations and emission norms, reduce costs, improve fuel efficiency of its vehicles, and achieve faster time to market new products. Dr Puranam says these applications include Simulia PowerFLOW Computational Fluid Dynamics (CFD) solutions, Simulia Abaqus Unified FEA and Simulia CST Studio Suite. The said carmaker uses these solutions to transform its vehicle design process and improve efficiency across the product development lifecycle for its portfolio of passenger vehicles, farm and tractor division, and electric vehicles.

The hour-long webinar highlighted the importance of using simulations to improve EMI/EMC testing in the automotive industry. By offering a complete analysis of 3D-EM inside automobiles, simulations can help engineers identify and address potential compliance issues early in the design process. This can lead to shorter development cycles, lower costs, and greater safety for drivers and passengers.