• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1425-1430
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• 2004

In this paper, the inductive power transformer using electromagnetic induction for the road/railway applied to contactless power transfer system is suggested and some ideas for power collector design to improve the power transfer performance are presented. The proposed the inductive power transformer is used for the light railway/road transportation system. which has a large air-gap and demands a large electrical power capability. But. low output power is generated due to a loosely coupled characteristic of the large air-gap. Therefore, double layer construction of secondary winding, which was divided in half to increase both output current and output voltage was suggested. In addition, the performance of inductive power transformer to alignment condition between the primary power line and the inductive power transformer was verified by computer simulation of 2kW model.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.266-270
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• 2001

This paper presents a novel topological prototype of voltage source series quasi-resonant zero current soft-switching pulse frequency modulated dc-dc power converter circuit using IGBTs which incorporates a high-frequency flyback transformer link. Its steady-state operating principle is described on the basis of simulation analysis, along with the open loop controlled power regulation characteristics of the multi-functional coupled inductors linked dc-dc power converter operating under a principle of zero current soft switching commutation.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.6
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• pp.437-445
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• 2021

This paper proposes an operating frequency design method that limits the voltage applied to aload-side converter during the initial operation of a loosely coupled resonant dual-active bridge (LCR-DAB) converter and an initial operating strategy that applies it. The LCR-DAB converter uses two wireless power transfer coils instead of the high-frequency transformer of the general DAB converter. The wireless power coil has a physical distance of several tens of millimeter or more between the two coils; thus, the LCR-DAB converter is a bidirectional isolated power conversion system that can easily achieve high insulation performance. However, for the initial operation of the LCR-DAB, if the power-side converter is operated at the resonance frequency while the load-side converter is not operating, then a very high voltage due to resonance is applied to the load-side converter, thereby causing damage to the converter. Therefore, a method that can stably charge the DC link voltage of the secondary-side converter during the initial operation is needed. This paper proposes a method to initially charge the secondary-side DC link by operating the primary-side converter at a frequency with limited voltage gain rather than at a steady-state operating frequency. The validity of the proposed frequency design method and initial operating sequence is verified through simulation and experimentation of the 1 KW LCR-DAB converter.

• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.218-220
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• 2004

In this paper, the concept of contactless inductive power transfer system used for the PRT system is suggested and some ideas for Power transformer design to improve the power transfer performance are presented. This system has a large air-gap and demands a large electrical power capability But, low output power is generated due to a loosely coupled characteristic of the large air-gap. Therefore, double layer construction of secondary winding, which was divided in half to increase both output current and output voltage was suggested. In addition, the performance of power transformer alignment condition between the primary power line and the power collector was verified by computer simulation of 2kW model.

• Journal of Power Electronics
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• v.18 no.1
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• pp.309-322
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• 2018

The technology of inductive power transfer has been proved to be a promising solution in many applications especially in electric vehicle (EV) charging systems, due to its features of safety and convenience. However, loosely coupled transformers lead to the system efficiency not coming up to the expectation at the present time. Therefore, at first, the magnetic core losses are calculated with a novel magnetic-circuit model instead of the commonly used finite-element-method (FEM) simulations. The parameters in the model can be obtained with a one-time FEM simulation, which makes the calculation process expeditious. When compared with traditional methods, the model proposed in the paper is much less time-consuming and relatively accurate. These merits have been verified by experimental results. Furthermore, with the proposed loss calculation model, the system is optimized by parameter sweeping, such as the operating frequency and winding turns. Specifically, rather than a predesigned switching frequency, a more efficiency-optimized frequency for the series-parallel (SP) compensation topology is detected and a detailed investigation has been presented accordingly. The optimized system is capable of an efficiency that is greater than 93% at a coil separation distance of 200mm and coil dimensions of $600mm{\times}400mm$.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.794-799
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• 2005

In this paper, the inductive power collector using electromagnetic induction for the PRT(Personal Rapid Transit) system is suggested and some ideas for power collector design to improve the power transfer performance are presented. The proposed the inductive power collector is used for the PRT system, which has a large air-gap and demands a large electrical power capability. But, low output power is generated due to a loosely coupled characteristic of the large air-gap. Therefore, double layer construction of secondary winding. which was divided in half to increase both output current and output voltage was suggested. Also, model of power collector and parallel winding structure are presented, in addition, the performance of inductive power collector to alignment condition between the primary power line and the inductive power transformer was verified by computer simulation of 2kW model.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.215-217
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• 2005

In this paper, the inductive power collector using electromagnetic induction for the PRT{Personal Rapid Transit) system is suggested and some ideas for power collector design to improve the power transfer performance are presented. The proposed the inductive power collector is used for the PRT system, which has a large air-gap and demands a large electrical power capability. But, low output power is generated due to a loosely coupled characteristic of the large air-gap. Therefore, double layer construction of secondary winding, which was divided in half to increase both output current and output voltage was suggested. Also, model of power collector and parallel winding structure are presented, in addition, the performance of inductive power collector to alignment condition between the primary power line and the inductive power transformer was verified by computer simulation of 2kW model.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1425-1427
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• 2005

In this paper, with loosely coupled transformer series-parallel resonant type DC/DC converter is analyzed. To get more efficient operating mode of the series-parallel resonant type DC/DC converter, theoretical analysis using normalized parameters are accepted. The proposed converter must be operated in Pulse Frequency Modulation(PFM) switching pattern for the Zero Voltage Switching(ZVS) operation. According to PFM control method, the output voltage of the proposed circuit can be controlled.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1610-1612
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• 2005

In this paper, the inductive power collector using electromagnetic induction for vehicle such as the PRT(Personal Rapid Transit) system is suggested and some ideas for power collector design to improve the power transfer performance are presented. The proposed the inductive power collector is used for the PRT system, which has a large air-gap and demands a large electrical power capability. But, low output power is generated due to a loosely coupled characteristic of the large air-gap. Therefore, double layer construction of secondary winding, which was divided in half to increase both output current and output voltage was suggested. Also, a model of power collector and parallel winding structure and a model of concentration/decentralization winding are presented, in addition, the performance of inductive power collector to alignment condition between the primary power line and the inductive power transformer was verified by computer simulation of 2kW model.

• Journal of the Semiconductor & Display Technology
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• v.4 no.1 s.10
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• pp.9-16
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• 2005

In this paper, with loosely coupled transformer Relies-parallel resonant type DC/DC converter is analyzed and adopted to the power source of a TFLM(Transverse Flux Linear Motor). To get more efficient operating mode of the series-parallel resonant type DC/DC converter, theoretical analysis using normalized parameters are accepted. The analysis includes a specially made ferrite transformer with two separately wound half cores in order to evaluate analytically and experimentally the changes in magnetizing the leakage fluxes and inductances caused by the distance between the halves. The proposed converter must be operated in switching Pattern III among the three switching patterns for the Zero Voltage Switching operation. According to Pulse Frequency Modulation(PFM) control method, the output voltage of the proposed circuit can be controlled. The results of the theoretical development are compared with practical measurements from a prototype system.