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This article develops magnetic dipole moment models based on Maxwell's equations for inductor's near magnetic field evaluation and reduction in power electronics systems. In the developed model, the near magnetic field source of an inductor is composed of the magnetic dipole moments from the winding and the air gaps. The superposition of the magnetic dipole moments determines the near magnetic field. The developed model can be easily applied to inductors with different winding and air gap configurations, such as those with lumped or distributed air gaps, for near magnetic field assessment and reduction. Simulations and experiments are conducted to validate the developed theory. [ABSTRACT FROM AUTHOR]

A high switching frequency isolated voltage-fed dual-transformer-based hybrid semidual active bridge converter is introduced in this article for unidirectional power flow and wide voltage range applications. The converter embraces the full-bridge and half-bridge properties under varying operating conditions to improve efficiency. Five appropriate working patterns are elaborated, including ideal output power derivation, current stress analysis, working voltage matching, output power distribution, and soft switching features. Afterward, a simple segmented control strategy is adopted in accordance with the analysis results. The zero voltage switching of all switches is achieved by introducing the magnetic current and suitable drive logic. Compared with the existing works, the proposed converter has outstanding merits in terms of reduced conduction loss, switching loss, and peak current of ac inductor, resulting in high conversion efficiency. Hence, the converter is more suitable for cases with wide and frequent input voltage variations. Eventually, the effectiveness of the converter and the control strategy is verified by a 1.0-kW prototype. [ABSTRACT FROM AUTHOR]

For isolated dc–dc power converters, the interwinding parasitic capacitance of the transformer is usually one of the main paths for common-mode (CM) noise. In order to simplify the CM noise analysis, this paper proposes a two-capacitor transformer winding capacitance model. The model is derived based on general conditions so it can be applied to different isolated converter topologies. A measurement technique is also proposed to obtain the lumped capacitance for the model. The CM noise models of several isolated converter topologies are analyzed with the proposed two-capacitor transformer winding capacitance model to achieve simplicity. Finally, the proposed transformer winding capacitance model and measurement technique are verified by simulations and experiments. [ABSTRACT FROM AUTHOR]