• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.5
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• pp.311-318
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• 2019

In general wireless power transfer systems (WPTSs), power transfer is controlled by the wireless communication between a transmitter (Tx) and a receiver (Rx). However, WPTS is difficult to apply in electronic products that do not have batteries, such as TVs. A WPTS with resonators based on a transformer of LLC series resonant converter is proposed in this study to eliminate wireless communication units between a Tx and an Rx. The proposed system operates at the boundary of the resonance frequency, and the required power can be stably supplied to authorized devices even though some misalignment occurs. Moreover, standby power standards for the electronic product can be satisfied.

• 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.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.6
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• pp.543-550
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• 2003

Thin paper proposes a new three-phase rectifier that actively shapes the input current sinusoidal by means of two rectifier bridges, each followed by a dc-dc boost converter. The proposed approach draws sinusoidal input current at unity power factor and has output voltage regulation capability The size and weight of magnetic material Is reduced by Incorporating a low KVA three-phase autotransformer and by directly connecting the dc outputs each other without using low frequency interphase transformer(IPT). The operation principle is described along with simple control method, and experimental results on a 1.5KW prototype are provided.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.3
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• pp.228-236
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• 2022

The charging methods of electric vehicles are divided into wired charging and wireless charging. Restrictions on the use of charging infrastructure for wireless charging vehicles currently exist because most charging infrastructure uses the wired charging method. Thus, wired and wireless integrated charging system has been studied. In this system, a wireless charging system especially requires a control method for high-efficiency operation in consideration of a change in a coupling coefficient. Therefore, this paper introduces two control methods for the high-efficiency operation of wireless charging that can be applied to wired and wireless integrated charging systems. In addition, loss analysis is performed through PSIM simulation to select a more advantageous method for high-efficiency operation among the two control methods. To verify the simulation-based loss analysis result, the two control methods are applied to the actual wireless charging system, and the efficiency is compared through the experiments Based on the experimental results, a control method suitable for high-efficiency operation of the wireless charging method is selected.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1413-1418
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• 2004

This paper shows the analysis of the inductive power transfer system in conjunction with series resonant converter operating variable high frequency. Of particular interest is the sensitivity of the complete system to variations in operational frequency and parameters. In inductive power transfer system, electrical power is transferred from a primary winding in the form of a coil or track, to one or more isolated pick-up coils that may relative to the primary. The ability to transmit power without contact enables high reliability and easy maintenance that allows inductive power transfer system to be implemented in hostile environments. This technology has found application in many fields such as electric vehicles, PRT(Personal Rapid Transit) etc. The coupling between the primary and secondary is then presented to include the effects of parameter and operational frequency variation.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.218-220
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• 2005

This paper shows the analysis of the inductive power transfer system in conjunction with series resonant converter operating variable high frequency. Of particular interest is the sensitivity of the complete system to variations in operational frequency and parameters. In inductive power transfer system, electrical power is transferred from a prima교 winding in the form of a coil or track, to one or more isolated pick-up coils that may relative to the primary. The ability to transmit power without contact enables high reliability and easy maintenance that allows inductive power transfer system to be implemented in hostile environments. This technology has found application in many fields such as electric vehicles, PRT(Personal Rapid Transit) etc. The coupling between the primary and secondary is then presented to include the effects of parameter and operational frequency variation.

• Proceedings of the KIPE Conference
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• 2016.11a
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• pp.157-158
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• 2016

본 논문에서는 위상 천이 제어 기법이 적용된 전기자동차 배터리 충전용 무선 전력 전송 시스템의 손실을 분석한다. PSIM 시뮬레이션을 통해 결합계수에 따른 전력반도체 소자 및 공진 네트워크의 손실을 이론적으로 계산하며, 송 수신패드의 손실을 FEM 시뮬레이션을 이용하여 도출한다. 계산 결과를 바탕으로 각 결합계수에 따라 소자에서 손실 분포를 확인하고 전체 효율에 영향을 미치는 요소를 분석한다.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.289-298
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• 2014

Recently, the traditional paradigm in railroad technology is changing as more efficient and cost-effective electric vehicle (EV) technologies have emerged. The original concept of PRT (Personal Rapid Transit) proposed in the past has come to be regarded as unrealistic, but its feasibility is improving through the utilization of an EV platform. In particular, battery-powered vehicles pose difficult technical challenges in attempts to achieve reliable and efficient operation. However, based on the inductive power transfer (IPT) technology, the fast charging of supercapacitors with high energy density can contribute to overcoming this technical challenge and promote the transition to electric-powered ground transportation by improving the appearance of cities. This study discusses the development process of a power supply system for PRT, including concept design, numerical analysis, and device manufacturing, along with performance predictions and evaluations. In terms of results, the system was found to meet the performance requirements for power supply modules on a test-bed.