Advanced Materials – The Key to Progress

We are a global company with our headquarters in Hanau, Germany. We currently have approximately 4300 employees who are spread over production and sales locations i more than 50 countries on every continent generating annual sales of approximately EUR 380 million. VACUUMSCHMELZE GmbH & Co. KG (VAC) is a leading global manufacturer of modern magnetic alloys, cores and inductive components. VAC has supplied innovative solutions for electromagnetic compatibility (EMC) protection for more than 30 years. Contents Introduction Superior EMC filter- and common mode choke design Standard series VITROPERM...

Nowadays power electronics have a decisive influence on the technology of electrical energy generation, distribution and conversion. Modern semiconductors enable ­electrical energy to be controlled and converted rapidly and safely with low losses. However, using today’s fast switching technologies results in significant network disturbances. To minimize these disturbances and stabilizing electric networks, EMI filters according to latest international standards must be used. VAC’s VITROPERM® EMC products make a significant contribution in building innovative and compact filter designs with lowest...

VITROPERM – extending the possibilities of iron Nanocrystalline VITROPERM alloys are based on Fe with Si and B with further additions of Nb and Cu. VAC pioneered the development of rapid solidification technology resulting in the production of thin tapes or ribbons approximately 20 µm thick. ­ pecial slitting and core winding machines produce tape-wound cores with external diameters ranging from 2 mm S to 600 mm. A subsequent heat treatment at around 500 - 600 °C transforms the initially amorphous microstructure of the tape into the desired nanocrystalline state, this being a two-phase structure...

Superior EMC Filter and Common Mode Choke Design Nanocrystalline cores are widely used in common mode choke (CMC) applications due to their unique combination of properties. By utilising low-cost raw materials (Fe-based) and modern, large-scale production, VITROPERM is a very ­ c ­ ompetitive solution for a wide range of applications. Our CMCs feature high attenuation which is maintained across a wide frequency range offering extremely broadband attenuation. In many cases, this characteristic can a ­ llow a reduction of the number of filter stages in multistage EMC filter configurations to reduce...

Features & benefits of VITROPERM nanocrystalline chokes Advantages Small size Suitable for high currents and/or high voltages High µ, high BS, suitable core geometries Single stage filter designs possible Excellent broadband attenuation behaviour, high permeability, ­ l ­ow-capacitance design, moderate reduction of µ up to high f ­requencies, low Q factor in 150 kHz range High efficiency, low power loss Low number of turns required for high L, reduction of ­ilter stages f ‘Green’, environmentally friendly Low power loss, reduced use of material Suitable for high and low ambient temperatures and...

VITROPERM vs. ferrite Due to the optimized high-frequency properties, the insertion loss of our nanocrystalline common mode chokes is superior ­ compared to that of a typical ferrite choke in the relevant frequency range. ­ Insertion Loss insertion loss aE [dB] (50 Ohm system) The properties of VITROPERM are very much different from conventional ferrites. In low-frequency ranges the permeability of VITROPERM 500 F is higher than that of ferrites. N ­ anocrystalline materials show a less marked reduction of permeability µ at higher frequencies. This has to be considered in the filter design for...

Permeability and magnetization curve Johannes Beichler / KB-E BE Abb7 / Abb_04_05_06_07_08_09_10_11 en neu 2016.xls [Seite 1/1] Erstellt: 08.03.05 / 15:26 VITROPERM is basically similar in this respect. The flat sector of μ(f) of VITROPERM 500 F ranges (depending on the initial permeability level) to frequencies of several 10 kHz (20 kHz in this example), only. Consequently, attenuation (or |Z|) is already dominated by Re(Z) and is always broadband in the whole EMC-relevant range above 150 kHz. Inductance plays a minor role and describes the attenuation only partially. The determining factor...

Thermal properties The saturation flux density of VITROPERM changes by only a few percent in the operating temperature range of up to 150 °C, while MnZn ferrites decline by up to 40 % at temperatures above 100 °C (fig. 9). The high Curie temperature of V ­ITROPERM alloys (above 600  allows short term °C), maximum operating temperatures as high as 180-200 °C1). The permeability of VITROPERM typically changes by less than 10 % in the temperature range from -40 °C to 120 °C, while the permeability of MnZn ferrites can drift in a range of ± 40 - 60 % around the room temperature value (fig. 10). relative...

Saturation behaviour High permeability nanocrystalline cores enable very high inductance levels in extremely compact core or choke ­ d ­imensions. However, as a consequence, an increased s ­ensitivity to asymmetric magnetization conditions caused by common mode, unbalanced or leakage currents has to be considered. These currents may occur as low-frequency leakage currents (50/60 Hz) or as medium or high-frequency interference currents. These are caused for example by long motor cables with different capacitance of the individual conductors to earth, or by resonances which occur ­(commonly due...

VITROPERM is determined to a small part by inductance L in this frequency range). High permeability VITROPERM 500 F cores are characterized by an extremely high attenuation or impedance at low frequencies, and they are clearly superior against ferrites at high frequencies. However, the price of this superior performance is a more sensitive saturation b ­ ehaviour, which is improving with increasing frequency but still more critical than that of other core materials. It should be noted that fig. 12a shows the saturation currents of the cores without winding. Depending on the number of turns, the...