EMC filters with high frequency stability for power electronics

EMC filters reduce interference currents in power converter systems which are generated by parasitic effects and cyclic elements of the system. The material plays an important part in this: the target is to achieve stable inductance over the entire frequency spectrum in order to maximise interference suppression.

Compared with standard technologies which use materials such as ferrite, electrical steel sheets and nanocrystalline metal sheets, interference levels with the new EMC filters from SMP are as much as 40dB[µV] (decibel microvolt) lower. The SMP filters are compact, up to 30% lighter, and noiseless because they are made from magnetostriction-free materials.

The overall efficiency of the system is improved due to very low losses through the materials. Moreover, fewer filter components are needed, so volume is reduced and the cost effectiveness of the power electronic system as a whole is increased substantially.

The filters can be manufactured with single or magnetically coupled chokes, and so offer a choice for reducing common mode and differential mode interference.

The component portfolio is designed for currents of up to 2,000A, up to 3,000A for special applications, and for frequencies up to the gigaHertz range. The materials have been developed and manufactured by SMP specifically for this purpose and have high saturation induction of up to 2 Tesla.

The individual components can be produced with dimensions from 19-300mm and weights from 0.05-130kg. The temperature class H (up to 180°C) insulation system is UL certified. Depending on the application, protection ratings up to IP66 are available. HL classes according to EN 45545 can be specified according to requirements.

The filter systems and inductive components are used in industrial applications in the power electronics, automation and signal processing sectors, in drive applications for railway engineering, electromobility and marine engineering among others, in medical technology, renewable energies and power supply and in the aerospace industry.