Analysis of common‐mode electromagnetic interference noise in a flyback converter using a self‐supply power control integrated circuit

Abstract

This study analyses electromagnetic interference (EMI) noise sources generated from a new type of flyback converter which is operated from a self-supplied power control integrated circuit (IC). On the basis of analysis, a new analytical mathematical model of common-mode (CM) EMI noise path is presented. This model is easier to construct and allows researchers to better understand the impact of each parameter on CM EMI noise than former models. According to the proposed model, the capacitors from the traces connected to the ground (GND), voltage drain drain (VDD), current sense (CS) and feedback (FB) pins to the ground demonstrate the greatest impact on CM EMI. Two improved layouts are designed to verify the analysis result. The layouts were driven by the newly developed model. Test results show that they correspond with theoretical calculations supporting the analysis and the model that was developed in the course of this work.

Analytical Models Synthesis of Power Electronic Converters

“…In the frequency domain, and by developing the convolution product, the output signal Sout(f) ( Fig.4) can be expressed as in (5), where Fsw is the switching frequency.…”

“…In order to comply with ElectroMagnetic (EMC) standards, an accurate prediction of a common mode (CM) and differential mode (DM) conducted noise is necessary. Furthermore, since ElectroMagnetic Interference (EMI) filters are coupled to converters, the optimisation is necessary reached with the knowledge of converter's impedances [1][2][3].Several papers treat the converter's modelling with different techniques: Terminated/Unterminated models [4][5][6], lumped circuits [7][8][9][10]...etc. However, the proposed models deal only with one kind of converter, this cannot be generalised to other conditions, due to the parameter's dependency.…”

An EMI‐Optimized Transformer for De‐Y Flyback Converter with Low Common‐Mode Noise

“…In flyback converters, the optimization of the transformer structure to reduce CM noise is the most cost-effective [22,23]. However, the balanced winding method and potential matching method still have the problems of weak suppression effect and poor universality.…”

LCL Filter Design with EMI Noise Consideration for Grid-Connected Inverter

“…Furthermore, current harmonic distortion of the grid-connected power inverter must be considered because of the power quality requirement in the power grid. In addition to the power quality of the power grid, another important issue is the conducted electromagnetic interference (EMI), which is mainly generated by the high frequency transistor switching and parasitic components in the noise conduction path [13][14][15]. Mostly, the EMI noise in the DC side of the inverter is suppressed to meet the EMI standard [16].…”