Practical EMI-filter-design procedure for high-power high-frequency SMPS according to MIL-STD 461

Forward converter is popular for isolated switching power supply. Generally, power switching converters are the sources of electromagnetic interference (EMI) because of their high transient voltage and current. In this study, reduction of conducted EMI in the single-switch forward converter is examined using a symmetric topology. At this end, the forward converter topology is modified to achieve a symmetric topology. EMI model of the conventional forward converter and symmetric forward converter are derived taking into account the main parasitic of components and printed circuit tracks. Accuracy of the predicted EMI is verified by the measured EMI for two converters. In addition to the symmetric approach evaluation from the EMI viewpoint, the effect of this approach on the output voltage noise is examined. Finally, the combination of a passive EMI filtering with the symmetric method is utilised for EMC compliance.

Section: Experimental Results Of Regular and Symmetric Forward Convmentioning

confidence: 99%

Conducted electromagnetic interference evaluation of forward converter with symmetric topology and passive filter

Yazdani¹,

Filabadi²,

Faiz

2014

“…Hence it is essential that EMC must be considered at the initial stage of PEC design. EMI filters and electromagnetic shielding techniques are conventionally adopted for EMI suppression but these techniques lead to increased cost, volume, weight, and reduced efficiency [17]. Existing control methodologies for EMI suppression follows two basic techniques, (i) making the system chaotic by continuously varying the converter parameters [18] and (ii) the use of external chaotic circuit to operate the converter in chaotic mode.…”

Section: Introductionmentioning

confidence: 99%

Analysis and mitigation of conducted EMI in current mode controlled DC–DC converters

Subramanian

Uma

2019

Practically, power electronic circuits (PECs) generate electromagnetic interference (EMI) which influence the operation of electronic equipment and may create instabilities. PECs must comply with electromagnetic compatibility standards for stable periodic operation but indeed fail under certain conditions. This study reports the effect of conducted EMI in a current mode controlled higher-order DC-DC converter fed from a pulsating DC voltage instead of a stiff DC voltage. The converter is found to be a source of conducted EMI under light loading conditions adversely affecting the systems' stability. A non-feedback control technique is implemented to mitigate the instabilities caused by EMI and to make the system electromagneticaly compatible. A mathematical model is developed to describe the dynamics involved. Simulation and experimental results are presented to support the analyses documented.

“…The permissible limits for EMI are defined by various regulations (National and International), among them the best-known standard is given by MIL-STD-461. Thus, according to MIL-STD-461E standards, the frequency range for conducted emissions in power leads should be limited within 30 Hz-40 GHz [4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Analysis on the effect of external spurious signals in an H‐bridge inverter

Subramanian

Uma

2018

Power electronic converters are consistently encountering complex non-linear behaviours predominantly due to the coupling of electromagnetic interferences (EMIs). The emergence of non-linear phenomena in a DC-AC H-bridge inverter under the influence of periodic interference signals at multiple locations is investigated. A detailed analysis is performed to determine the bifurcation boundaries under the influence of spurious signals and parametric variations. The analysis will enable the engineers to select the design parameter cautiously to avoid the occurrence of undesirable instabilities. The converter dynamics are investigated with the help of numerical simulations executed in MATLAB/SIMULINK environment and analytically validated using the concept of monodromy matrix based on Filippov's method of differential inclusion. Simulation and theoretical results are validated experimentally.