• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.2
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• pp.119-126
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• 2010

An integrated magnetic (IM) transformer is proposed for a phase shifted full bridge (PSFB) converter with zero voltage switching (ZVS). In a proposed IM transformer, the transformer is located on the center leg of E-core and the output inductor is wound on two outer legs with air gap. The proposed IM transformer is analyzed by using the magnetic capacitor model. For reducing the core size, EE core is redesigned. The proposed IM transformer is experimentally verified on a 1.2 kW prototype converter. The converter efficiency with the proposed IM transformer is about 93 % at full load and its volume size can be reduced. It can be expected that the power density can be largely increased with the proposed IM transformer.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.3
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• pp.262-272
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• 2015

An integrated two-in-one transformer applicable to PSUs for a 120 W LED TV is proposed. This transformer comprises a PFC inductor and an LLC transformer placed and integrated on an E-I-E type magnetic core. Performance is evaluated by observing the coupling coefficients of the proposed two-in-one transformer under various air gap topologies. Among the topologies studied, an integrated transformer with centered air gap shows stable operational characteristics with a minimized mutual coupling (interference). Furthermore, applicability of the proposed integrated transformer to PSUs for a 120 W LED TV is studied from the viewpoint of integrating different magnetic components into one core, resulting to low weight, low cost, and high power density.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.1
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• pp.27-35
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• 2017

In this study, an integrated 2-in-1 transformer for a low-weight and low-cost light-emitting diode lighting power supply is proposed. In the transformer, a power factor correction (PFC) inductor and an LLC resonant transformer are placed and integrated on a single magnetic core. The amount of mutual interference, represented by the coupling coefficient, between magnetic fluxes generated from each magnetic source is minimized by using the new shape core of an integrated 2-in-1 transformer. The design consideration on critical conduction mode PFC converter and LLC resonant converter using the proposed 2-in-1 integrated transformer is described, and the overall performance of the 150 W LED PSU shown through the experiment.

• Journal of Magnetics
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• v.21 no.4
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• pp.644-651
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• 2016

A novel zero voltage switching (ZVS) phase shift full bridge (PSFB) converter used in geophysical exploration is proposed in this paper. To extend the ZVS ranges and increase power density of the converter, external inductor acting as leakage inductance is applied and integrated into the integrated magnetic (IM) transformer with separated secondary winding. Moreover, the loss of ZVS PSFB converter is also decreased. Besides, the analysis and accurate prediction methodology of the leakage inductance of the IM transformer are proposed, which are based on magnetic energy and Lebedev. Finally, to verify the accuracy of analysis and methodology, the experimental and finite element analysis (FEA) results of IM transformer and 40 kW converter prototypes are given.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.85-87
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• 2012

This paper describes the design and analysis of an integrated transformer magnetic core which comprises of two different power cores with PFC inductor and LLC resonant transformer magnetic cores. The equivalent magnetic circuit modeling approach is employed to analyze the variations in coupling coefficient and inductance in terms of air gaps under the operations of the respective power core. Simulation and experimental studies are performed with a fabricated prototype integrated core and their results are discussed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.4
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• pp.35-45
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• 2008

This paper present the Three-Level converter using IM(Integrated Magnetics) method for high power application. In power conversion system, magnetic components are important devices used for energy storage, energy transfer, galvanic isolation and filtering. The proposed Three-Level converter is to reduce the number of magnetic components using transformer integrated with output inductor. This paper proposes reluctance model base on the magnetic analysis for the Three-Level converter. Also, the secondary rectification was discussed by a single core transformer winding. A protype featuring 540[V] input, 48[V] output, 40[kHz] switching frequency, and 3[kW] output power using IGBT.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.157-159
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• 2020

This paper presents an optimal planar transformer design of a 3-kW Low voltage DC-DC Converter (LDC) with 3.68 kW/L power density for electric vehicle (xEV) application. The transformer is optimized based on the trade-off between footprint and loss using the proposed figure-of-merit (FOM) based optimization. In order to achieve ZVS under entire load range, an external leakage inductance is added and implemented using the proposed magnetic integration technique. A comparison between non-integrated and integrated magnetic core using finite element analysis (FEA) is presented. The result shows that the integrated core can reduce the core loss up to 35 % and core boxed volume up to 15 % compared to the non-integrated core. Experimental results are also provided to validate the proposed magnetic integration technique.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.40-42
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• 2008

This integrated magnetic (IM) transformer is proposed for a phase shifted full bridge (PSFB) converter with zero voltage switching (ZVS). In a new IM transformer, the transformer is located on the center leg of E-core and the output inductor is wound on two outer legs. The proposed circuit is analyzed electrically and magnetically. An E-core is redesigned and implemented. The proposed IM transformer is experimentally compared with the conventional one through a 1.2kW prototype converter.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.5
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• pp.437-447
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• 2015

In this paper, implementation of an integrated transformer applicable to power supply units (PSUs) for a 150-W LED with a wide range of output voltage is presented. The transformer is comprised of a PFC inductor and an LLC resonant transformer, each of which is placed and integrated on an E-I-E-type magnetic core. Integrated transformers with two different air gap topologies (i.e., the side and center gap topologies) are considered in the design phase to investigate their applicability. The design consideration on the LLC resonant converter used for the wide-output-voltage control ranges is described, and the overall performance of the proposed system is verified through realization of it onto a 150-W LED PSU board.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.406-409
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• 2008

This paper presents the integrated magnetic circuit designing method for phase shift full bridge(PSFB) converter. The integrated magnetic circuit is implemented on redesigned of EI core. The transformer windings are located on center leg and the two inductors are located on the outer legs with air gap. Based on the equivalent circuit model, the principle of operation of the PSFB converter is explained. The operation and performance of the proposed circuit are verified on a 1.2 kW prototype converter. The analysis and design of the integrated magnetic circuit is verified through the experimental and simulation results.