Protecting the Present and Future of Mobility from Noise

Modern automobiles, especially EVs and hybrid electric vehicles (HEV), are both precision electronic devices on wheels and sources of electromagnetic noise. These opposing characteristics present a new challenge in development known as EMC.* Suppressing noise generation and enhancing noise immunity are crucial. EMC is a critical requirement for integrating mobility with social infrastructure. Masayoshi Hirota of the Power Integration Laboratory at ANTech expresses a strong commitment to overcoming this challenge.

“The inverter is an essential component of an EV, which optimally controls power from the battery to drive the motor. However, voltage and current fluctuations during inverter operation generate high-frequency electromagnetic noise. Additionally, the interior of a vehicle is made up of various devices that act as noise sources. If left unaddressed, these issues can cause not only disturbances to the car navigation display and audio but also, in the worst-case scenario, system malfunctions that could lead to serious accidents endangering lives. As autonomous driving technology advances, ensuring electromagnetic quietness inside the vehicle will become a critical factor in determining the reliability of mobility.” (Hirota)

Typically, noise mitigation measures have been coordinated by car manufacturers for the entire vehicle. However, with the increasing specialization of electric units and increased output power and power density, strict electromagnetic shielding by each unit’s suppliers has become essential. For example, in inverters, EMC filters with magnetic cores or integrated into the power distribution system are installed at the input and output to suppress noise ingress and egress. As performance demands increase, conventional cores become larger, creating significant constraints on layout.

* EMC: electromagnetic compatibility

“In 2021, we received an inquiry from a customer regarding EMC design for drive-system inverters. However, at that time, we didn’t have any knowhow in that area.” (Hirota)

The biggest obstacle was the gap between the development team, which aimed for ideal circuit design, and the manufacturing team, which prioritized mass production efficiency. Efforts to minimize noise require wiring that is both short and complex, leading to concerns from the manufacturing floor, “This structure is impossible to assemble.” “Ideal performance or stable mass production?”

While navigating conflicting demands, Hirota repeatedly visited the production floor and relentlessly made adjustments. For six years, he continuously sought the optimal solution that would enable production lines, supported by 250,000 employees, to achieve stable output without any compromise on performance. As a result, a system was established to commence the first mass production in 2027. This transformation into manufacturable cutting-edge technology earned Hirota and his team unwavering trust.

Meanwhile, Hirota is looking even further ahead. This reflects a sense of urgency that simply assembling parts sourced from external suppliers will not enable the company to win the inevitable cost competition.

“What we aim for is our proprietary EMC power distribution components that integrate our materials and products. Currently, the mainstream approach involves assembling the EMC core afterwards, requiring designs that accommodate dimensional accuracy and assembly tolerances, which leads to larger overall sizes. How can we achieve miniaturization that satisfies customers? The key to solving this challenge was the collective strength of our group.” (Hirota)

We leveraged the EMC design and evaluation technologies developed by ANTech together with the metal and plastic material technologies of the Sumitomo Electric Group. We successfully established the ultimate EMC filter concept that integrates our power distribution materials and EMC components into a unified unit. Hirota’s team is currently dedicated to developing key technologies.

“If you entrust noise countermeasures to the Sumitomo Electric Group, your noise challenges will be solved. We want to establish ourselves as a trusted development partner who deserves such confidence.” (Hirota)

Hirota has announced his intention to move beyond the role of a supplier and become a strategic partner that co-creates the future with car manufacturers. This involves connecting electric power and information while eliminating invisible noise. The steady development of each individual technology will continue to fundamentally support the essential infrastructure of the next-generation mobility society: safety and security.