Methods of Assessing the Effectiveness of Filter Elements in Power Electronics

Abstract

Newly constructed devices must meet a number of requirements in terms of the level of generated disturbances. To achieve an acceptable level in such devices, filters are installed—one of the cheapest ways to reduce interference in devices. One of the key elements of the filter that is responsible for the effectiveness of noise reduction are ferrites. Unfortunately, for various devices, an individual approach should be used in the selection of filters and, accordingly, ferrites. Due to the fact that ferrites from different manufacturers do not have standardized characteristics and information on their effectiveness, the selection of the right ferrite is a very time-consuming process. Therefore, this article will present the possibilities of quickly determining selected ferrite parameters in order to ensure the necessary level of noise reduction. For this purpose, assumptions from the CISPR 17 standard will be used. For selected types of ferrites, a large number of measurements were carried out in order to determine the optimal computational algorithm for adjusting ferrite characteristics to the designed conditions. The performance of these tests will be the basis for conducting tests on a larger number of ferrites, as well as for the development of possible standardization procedures.

Diversity Pertaining to the Attenuation of the RF Disturbance Suppression Power Line Filters

“…Due to [9], the relations between the single-ended S-Parameters presented above and the common-mode input and common-mode output modal S-Parameters S CC yield For the specific case presented in Figure 1, the general formula presented by Equation (11), with the introduction of the formulas from Equations ( 3)- (10), can be simplified as follows:…”

“…For the specific case presented in Figure 1, the general formula presented by Equation ( 13), with the introduction of the formulas from Equations ( 3)- (10), can be simplified as follows:…”

“…One was based on direct measurement and the other on a modal S-matrix built from the single-ended S-Parameters. This paper focuses on the ambiguity due to these two definitions and provides a solution in which both attenuations are identical.Due to the fact that the parameters of the filter depend on the materials of its components, one filter was tested for all cases in the article [10,11].…”