High-Frequency, Low-Loss Design and Application of Nanocrystalline Common-Mode Inductors for 800V High-Voltage Fast-Charging Platforms

Can it charge 200 kilometers in just 5 minutes? The “silent guardian” behind 800V fast charging turns out to be a tiny magnetic ring!

In-depth Analysis: Why Have Ferrites “Lost Their Voice” in the High-Voltage Era, While Nanocrystalline Common-Mode Inductors Have Become a Fierce Battleground for Automakers?

While your car is enjoying a cup of coffee in the charging zone—just 5 to 10 minutes—its range has already increased by 200 kilometers. This “charging like refueling” experience will become a reality by 2026.

Xpeng G9, Zeekr 007, Xiaomi SU7 Ultra… equipped with 800V high-voltage platform This vehicle model has become mainstream. But have you ever wondered: Behind this astonishing charging speed lies an invisible “electromagnetic storm”?

Data Alert: When operating at 800V, the switching frequency can exceed 100kHz, resulting in electromagnetic interference (EMI) levels that are significantly higher than those of conventional 400V systems. 3 to 5 times If left unchecked, at the least, the car radio will be filled with static; at worst, it could cause the autonomous driving radar to misinterpret data and lead to failure of the BMS battery management system.

Guarding the heart of this storm is a tiny magnetic ring called a “nanocrystalline common-mode inductor.”

I. The Double-Edged Sword of Speed and Noise: EMI Challenges in the 800V Era

As new-energy vehicles evolve toward 800V and even higher voltage platforms, power density has significantly increased. According to... Bezels Consulting Data shows that by 2025, the global market size for 800V fast charging stations will have reached... 63.789 billion yuan China accounts for over one-third.

However, high voltage, high current, and high switching frequency (as seen in SiC/GaN devices) pose severe electromagnetic compatibility (EMC) challenges:

• A surge in high-frequency noise: Silicon carbide (SiC) inverters have extremely fast switching speeds and a very high dv/dt (rate of voltage change), generating significant high-frequency common-mode noise.
• Traditional solutions have failed: Previously commonly used Ferrite cores are prone to magnetic saturation under high frequencies and large DC bias. Once saturation occurs, the inductance drops sharply, and the filtering effect instantly becomes zero.
• The challenge of temperature rise: High-frequency losses cause severe heating of the magnetic core, and in hot summer environments, this could trigger a risk of thermal runaway.

II. The Game-Changer Takes the Stage: The “Dimension-Reduction Strike” of Nanocrystalline Materials

Faced with the stringent requirements of 800V, nanocrystalline alloy—thanks to its unique microstructure—has become the ideal material for next-generation common-mode inductors.

🔬 A Head-to-Head Battle of Core Performance: Nanocrystalline vs. Ferrite

Technical Principle: Nanocrystalline materials consist of grains with diameters ranging from only 10 to 20 nanometers embedded in an amorphous matrix. This unique structure not only retains the high resistivity of amorphous alloys—thus reducing eddy-current losses—but also boasts the high magnetic permeability characteristic of crystalline alloys, making it a true "masterpiece" that combines the best of both worlds.

In 800V on-board chargers (OBCs) and DC-DC converters, the use of nanocrystalline common-mode inductors can— EMI noise attenuation improved by more than 20 dB and simultaneously reduce the size of magnetic components. 30%-50% 。

III. Market Boom: From “Optional” to “Essential”

The years 2025-2026 mark the breakthrough year for nanocrystalline magnetic components in automotive-grade applications.

• Increased value of bicycles: According to industry research, as 800V systems become more widespread, the quantity and value of nanocrystalline magnetic cores used in each electric vehicle will increase compared to 400V models. Over 30% In an 800V vehicle, the demand for nanocrystalline materials from common-mode inductors, differential-mode inductors, and shielding components can reach... Several hundred yuan 。
• Market Size Forecast: By 2026, the market size for high-end nanocrystalline magnetic components used in new energy vehicles in China alone is expected to exceed. 6 billion yuan , with a compound annual growth rate (CAGR) exceeding 35%。

IV. Future Outlook: Going Beyond the Car

The application scenarios for nanocrystalline common-mode inductors extend far beyond just new-energy vehicles.

• AI Data Center: As the power consumption of AI servers soars, solid-state transformers (SSTs) based on nanocrystalline materials and high-frequency inductors will become key to reducing the PUE value.
• Photovoltaic energy storage: In megawatt-scale photovoltaic inverters, nanocrystalline devices can significantly enhance conversion efficiency and reduce energy waste.
• Wireless charging: The ultra-thin nanocrystalline shielding sheet is a “standard component” of high-power wireless charging systems, effectively preventing magnetic leakage interference.

If you have a need for nanocrystalline common-mode inductors, please feel free to contact us.

(Note: Some of the data in this article are compiled from Zhongyan Puhua, BZ Consulting, and publicly available industry research reports as of February 2026.)