Introduction: The EMC standard of frequency ranging from 150 KHz to 30MHz on restraining the conducted CM EMI are becoming more serious in the application. CM inductors and filter capacitors are used to restrain the CM EMI. Ferrite cores and common Nano-crystalline cores are popular in the domestic market as common mode choke cores. However, high volume and impedance reduction from150 KHz to 30MHz due to the operating frequency limitation can cause core mulfunction. Nanocrystalline cores can be applied to EMC switch power modules, UPS power supply, communication power supply, inverter, transducer, and home appliance. Characteristics: - High initial permeability. - High saturate induction density:not easy to be saturated in high current fields. - Excellent temperature stability: stable working ablity at temperatures from -55 ℃ to 130 ℃ for a long period of time and work at higher Curie temperature; able to maintain stable properties even in unstable working temperature. - Good frequency flexibility - better noise control ability in different frequencies. - Higher anti-unbalanced-current: special made Nano-crystalline EMC Common Mode Choke Cores guarantee 104 permeability when resisting 80A/m unbalanced current bias field. Craftsmanship Nanocrystalline alloys are formed by adding a certain amount of glass forming agent to the molten metal, and rapidly quenching and casting using a narrow ceramic nozzle under high temperature melting conditions. Amorphous alloys have the similar characteristics of glass structure, which not only make them have excellent mechanical properties, physical properties and chemical properties, but more importantly, the new technology of producing amorphous alloys using this rapid quenching method is less than the cold-rolled silicon steel sheet process. 6 to 8 processes can save energy consumption by 60% to 80%, which is an energy-saving, time-saving and efficient metallurgical method. Moreover, the amorphous alloy has low coercivity and high magnetic permeability, and its core loss is significantly lower than that of oriented cold-rolled silicon steel sheet, and its no-load loss can be reduced by about 75%. Therefore, the use of amorphous alloys instead of silicon steel sheets to manufacture transformer cores is one of the main means to save energy and reduce consumption in today’s powergrid equipment.