• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.323-324
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• 2014

A higher-order power converter topology for an extremely low coupling (less than 0.15) transformer with high efficiency and wide air-gap (23 mm) is presented in this paper. Among the typical resonant converter topologies for contact-less power transferring systems, Series-Series Resonant Converter (SSRC) and Series-Parallel Resonant Converter (SPRC) are widely used in number of power electronic applications. However, when coupling coefficient of a transformer is seriously low (k<0.5), the series-series resonant converter will possibly operate at short circuited condition because of the small magnetizing impedance. To solve this problem, a modified and improved topology of seventh-order resonant converter for contact-less power converter system is proposed and the results are presented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.4
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• pp.323-328
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• 2003

In this paper new control strategy of series resonant converter system for power supply of communication station is suggested. Frequency controlled series resonant converter system is robust to load variations because it is POSR(Parallel Output Series Resonant: POSR) type. And it provides stable output voltage by changing switching frequency to input voltage variations. Firstly, operation analysis about suggested series resonant converter system was carried. Then simulations using ACSL(Advanced Continuous Simulation Langage) and experiments to actual system were carried to prove characteristics of suggested system.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.69-72
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• 2003

In this paper new control strategy of series resonant converter system for control power supply is suggested. Frequency controlled series resonant converter system is robust to load variations because it is POSR(parallel output series resonant) type. And it provides stable output voltage by changing switching frequency to input voltage variations. Firstly, operation analysis about suggested series resonant converter system was carried. Then simulations using ACSL(Advanced Continuous Simulation Language) and experiments to actual system were carried to prove characteristics of suggested system.

• Journal of Electrical Engineering and Technology
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• v.11 no.1
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• pp.100-108
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• 2016

This paper presents a simple high efficiency full-bridge DC-DC converter using a series resonant capacitor. The proposed converter achieves the zero voltage switching of the primary switches under a wide range of load conditions and reduces the high circulating current in the freewheeling mode using the leakage resonant inductance and the series resonant capacitor. Thus, the proposed converter overcomes the drawbacks of the conventional full-bridge DC-DC converter and improves its overall system efficiency. Its structure is simplified by using the leakage inductance of the transformer as the resonant inductance and omitting the DC output filter inductance. Also it can operate over a wide range of input voltages. In this paper, the operational principle, analysis and design example are described in detail. Finally, the experimental results from a 650W (24V/27A) prototype are demonstrated to confirm the operation, validity and features of the proposed converter.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.472-475
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• 1999

An improved series-parallel resonant converter using auxiliary winding of resonant is presented. The conventional series-parallel resonan converter and newly developed converter are compared for high voltage application. This proposed converter gives several merits such a wide load ranges, small circulating current, low peak voltage at no load. Two experimental results for the proposed converter and conventional one are presented for conventional LCC type converter and the proposed one.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.9
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• pp.934-943
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• 1990

There are no turn-on losses in the series Resonant Converter which operates above the resonance frequency, and the commutation stress on the switched component is low. For a given Series Resonant Converter with specified load resistance, the output voltage is a function of the operation frequency. This paper describes the static and dynamic characteristic analysis of the Series Resonant DC to DC Converter, which is operating above the resonant frequency, with frequency control. For the analysis method, state plane technique is adopted, and the circuit operation is defined from normalized switching frequency, Fsn. Under this condition, circuit performance is analyzed ideally. The validity of the proposed analysis is verified by comparing with experimental results, the stability of the converter is confirmed against small variations around the operating point by conventional frequency domain analysis, and the stress quantity added to switch component is shown.

• Journal of Power Electronics
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• v.8 no.3
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• pp.275-279
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• 2008

An LLC series resonant converter has many unique characteristics and improvements over PWM topologies. However, many output capacitors are needed in parallel to satisfy output voltage ripple and the rated ripple current of the capacitors. This paper deals with a novel two phase interleaved LLC resonant converter using a phase of the resonant capacitor. The proposed converter can satisfy output voltage ripple and a rated ripple current of capacitors with few output capacitors, relatively. The operation and features are considered in detail and a prototype with a 12V-100A output is investigated.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.526-528
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• 2008

LLC series resonant converter has many unique characteristics and improvement over PWM topologies. However, many output capacitors should be needed in parallel to satisfy an output voltage ripple and a rated ripple current of the capacitors. This paper is deal with a novel two phase interleaved LLC resonant converter using a phase of the resonant capacitor. The proposed converter can satisfy output voltage ripple and a rated ripple current of capacitors with few output capacitors, relatively. The operation and features is considered in detail and a prototype with a 12V-100A output is investigated.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.1
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• pp.33-39
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• 2005

Comparing with the conventional transformer without the air gap, a contactless transformer with the large air gap between the long primary winding and the secondary winding has increased leakage inductance and reduced magnetizing inductance. For transferring the primary power to the secondary one, the high frequency series resonant converter has been widely used for the contactless power supply system with the large air gap and the increased leakage inductance of the contactless transformer However, the high frequency series resonant converter has the disadvantages of the low efficiency and high voltage gain characteristics in the overall load range due to the large air gap and the circulating magnetizing current. In this paper, the characteristics of the high efficiency and unit voltage gain are revealed in the proposed three-level series-parallel resonant converter. The results are verified on the simulation based on the theoretical analysis and the 5kW experimental prototype.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.3
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• pp.394-400
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• 2012

In this paper, charging modes of series resonant converter for a high voltage energy storage capacitor are compared in terms of charging time, peak resonant current, normalized peak resonant current and voltage in each operation mode. Operating principles of the full bridge series resonant converter with capacitor load are explained and analyzed in discontinuous and continuous operation mode. Based on the analysis and simulation result, $0.6{\omega}_r$ < ${\omega}_s$ < $0.75{\omega}_r$ and $1.3{\omega}_r$ < ${\omega}_s$ < $1.4{\omega}_r$ are evaluated to the best range of switching frequency for charging of an high voltage energy storage capacitor. 1.8 kJ/s SRC prototype is assembled with TI 28335 DSP controller and 40 kJ, 7 kV energy storage capacitor. Design rules based on the comparative analysis are verified by experiment.