As Rail Transit Speeds Up, Neodymium-Iron-Boron Magnets Power Motor System Enhancements

As China's national railway network accelerates its upgrade, the demand for speed increases in high-speed trains and urban rail transit has become increasingly urgent, with high-performance neodymium-iron-boron (NdFeB) magnets emerging as the core material for upgrading drive motor systems. China's independently developed NdFeB magnets specifically designed for subway traction motors have recently been deployed on multiple newly constructed lines, enhancing train operational efficiency by 15% and reducing energy consumption by 12%.

The rail transit sector imposes stringent requirements on the power density and speed regulation accuracy of drive motors, with traditional ferrite magnets struggling to meet the demands of suburban express rail services exceeding speeds of 160 km/h. Leveraging their high energy product characteristics, NdFeB magnets enable a 30% reduction in motor volume while simultaneously increasing output torque by 40%, making them a critical material for high-speed traction systems.

CRRC Zhuzhou Electric Company, in collaboration with rare-earth permanent magnet enterprises, has developed the 35UH series NdFeB magnets, which overcome high-temperature demagnetization challenges through gradient composition design. These magnets maintain a magnetic performance degradation rate of less than 5% under 180℃ operating conditions, meeting the demands of long-distance operations in China's diverse climatic conditions. The magnets have been applied in the Fuxing CR400BF-Z intelligent EMU on the Beijing-Hong Kong High-Speed Railway, improving the train's acceleration performance by 8% and reducing energy consumption per trip by 800 kWh.

In the urban rail transit sector, Shanghai Metro Line 14 utilizes a permanent magnet synchronous traction system equipped with NdFeB magnets, achieving a starting acceleration of 1.2 m/s², reducing travel time by 4 minutes per trip, and increasing daily passenger capacity by 12,000. Currently, NdFeB magnet-based motors developed domestically have been adopted in new subway lines across 28 cities in China, accounting for 65% of newly constructed lines.

Industry data shows that China's demand for NdFeB magnets in rail transit reached 3,200 tons in 2024, marking a 120% increase from 2020. Industry experts point out that with continuous breakthroughs in vibration resistance and aging resistance technologies for magnets, NdFeB materials will be further applied in the drive systems of maglev trains, propelling China's rail transit towards an ultra-high-speed era of 600 km/h.