Integrated emi filter with optimized ground winding layout for improved noise rejection

Abstract

The invention discloses integrated EMI (electromagnetic interference) filter for optimizing grounded winding layout to improve noise suppression performance. The integrated EMI filter comprises an E-type magnetic core, a first I-type magnetic core, a second I-type magnetic core and two common-mode winding units of the same structure and symmetrically disposed on the two sides of the second I-type magnetic core. On the basis of the research of the characteristics of component integration and various coupling effects among the components as well as by optimizing the grounded winding layout of the integrated EMI filter, the integrated EMI filter with a small structure, complexity and processing difficulty is capable of effectively eliminating equivalent parallel capacitance of a common-mode inductor. By high-frequency performance comparison of reverse coupling, forward coupling and bidirectional coupling, the conclusion that the bidirectional coupling grounded winding structure can improve high-frequency common-mode noise suppression capacity to the greatest extent is obtained. At the mean time, an equivalent circuit is introduced for the quantitative analysis of a design process, and an accurate field simulation software is used for simulating filtering effects so as to finish the processing and test of the integrated EMI filter.

Description

technical field [0001] The invention relates to the technical field of filters, in particular to an EMI filter with high performance and high integration, which can meet the design requirements of small size, broadband and integrated technology, and can be applied to power electronic systems. Background technique [0002] With the continuous improvement of the operating frequency of power semiconductor devices and the development of power electronic equipment in the direction of high density and miniaturization, the influence of electromagnetic interference caused by it on peripheral equipment has begun to attract much attention. [0003] Traditional filters are implemented using discrete components, however, there are some problems with EMI filters implemented using discrete components. First of all, due to the unavoidable parasitic parameters of discrete passive components, such as the equivalent parallel capacitance (Equivalent Parallel Capacitance, EPC) of the common mod...

AI Technical Summary

Problems solved by technology

Due to the resonance frequency of each branch and the coupling effect between components, the high-frequency performance of the filter will deteriorate, which is manifested by the reduction of the insertion loss of the filter, and it cannot work normally in the range of 150kHz-30MHz considered by conduction interference.

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