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Abstract

Broadband interference suppression with active narrowband filters

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Background

 

High-frequency circuits can cause electromagnetic emissions that impair other electronic systems. In power electronics, it is therefore often necessary to suppress EMC interference by such means as active narrowband filters. An invention from the Technical University of Dortmund suppresses interference in power electronics with an active counter-interference concept.

The interference-relevant frequencies are identified and corresponding counter-signals generated. The transmission function between counter-signal injection and measurement location for the interference or residual interference is taken into account. In ongoing operations, the counter-signal is continuously adjusted.

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Images & Videos

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Solution

Frequency-dependent interference suppression is influenced by adaptation increment, secondary path estimate quality within the FxLMS algorithm, and the manner in which several adaptive notch filters are arranged. Pseudo-cascaded adaptive notch filters thus provide comparatively broadband interference suppression, allowing reduction not only of discrete harmonics, but also of relatively broadband interference signals.

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Advantages

• Adaptive counter-interference signals
• Very broadband solution for a wide frequency range
• Lightweight

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Scope of application

More and more electrical systems involve DC voltage level adjustment or conversion between direct and alternating current. Circuits that reduce interference from these systems are thus gaining in importance. The invention essentially allows an FPGA to be implemented. It requires no large, passive components, so it is relatively low-cost and lightweight.

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Service

A prototype has been set up and measured in the laboratory, and function tests have confirmed that the invention is advantageous. Registration with the German Patent and Trade Mark Office and other subsequent international applications are possible in the priority year. We are offering interested companies the opportunity to license and refine the technology in collaboration with the inventors and the Technical University of Dortmund.