Bong-Gun Chung

A novel LLC resonant converter for wide input voltage and load range

Nowadays, some applications require high efficiency under wide load range and wide input variation. In order to get high voltage gain characteristics in a wide input and load ranges, the conventional LLC resonant converter requires a small magnetizing inductance, and a lot of losses by the higher magnetizing current can be generated in the switches and transformer. The proposed LLC resonant converter with two resonant tank circuits and auxiliary switches, even though large magnetizing inductance of the transformer is used, can get the high voltage gain characteristics in a wide input voltage and load ranges. Also, due to the reduced magnetizing current, losses and efficiency characteristics can respectively be reduced and improved. The proposed LLC resonant converter is described and verified through a 500W experimental prototype.

A low profile LLC resonant converter using novel planar transformer

In this paper, a low profile LLC resonant converter with two planar transformers is proposed for a slim SMPS (Switching Mode Power Supply). Design procedures and voltage gain characteristics on the proposed planar transformer and converter are described in detail. Two planar transformers applied to LLC resonant converter are connected in series at primary and in parallel by the center-tap winding at secondary. Based on the theoretical analysis and simulation results of the voltage gain characteristics, a 300W LLC resonant converter for LED TV power module is designed and tested.

A novel planar transformer for low profile LLC resonant converter

To cope with the high power density and low cost in switching power supply, LLC resonant converter with a new planar transformer is proposed in this paper. Modeling of a new planar transformer is discussed in detail and a 200W prototype of LLC resonant converter is tested to verify.

A study of novel flyback converter with very low power consumption at the standby operating mode

Recently, although the power consumption of green mode flyback converters at the light load and standby operating mode was minimized by the burst mode operation of PWM IC, the flyback converter has still about 0.3W~0.5W power consumption caused by the high magnetizing current flowing through magnetizing inductance of high frequency transformer in the primary side. PDP TV is required to reduce the standby power consumption by 0.2W. This paper proposes a novel topology of green mode flyback converter to decrease the standby power consumption by reducing the magnetizing current at the standby mode operation. A 70W prototype flyback converter for an auxiliary power module installed in 50” PDP TV is built, tested and verified. Its experimental results are described.

LLC Resonant Converter Using A Novel Planar Transformer

To cope with the high power density and low cost in switching power supply, this paper presents a novel planar transformer, which can regulate the leakage inductance of planar transformer used for LLC resonant converter. Modeling and analysis of a novel planar transformer are discussed in detail and a prototype 200W LLC resonant converter is tested to verify.

A novel topology of LLC resonant inverter with two resonant tanks for Power Conditioning System

Recently, Power Conditioning System (PCS) tends to require more compact, higher efficiency, higher power density with better performance. To meet these requirements, a novel topology consisted of LLC resonant converter with two resonant tanks for low power losses and Low Frequency (LF) cyclo-converter for sine wave filtering is proposed. The operating schemes are analyzed and described. A 400W proto product is built, tested and verified the performances by connecting the 110Vac 60Hz utility line. Test results are described with its high efficiency and good performance.

A Wide Input Voltage And Output Load Range LLC Resonant Converter with Two Resonant Tanks

In this paper, for the notebook adapter with power level below approximately 60W, a novel LLC resonant converter preceded by diode rectifier with a capacitor filter is presented. Due to the switching operation of the auxiliary switching device, the proposed LLC resonant converter can deliver power with the high efficiency characteristics from the universal line(110VAC/220VAC) and load conditions. The operating schemes on the proposed converter are analyzed and described. A 60W prototype product is built, tested and verified.

LLC Resonant Converter using Proposed Planar Transformer

In this paper, a new planar transformer with a novel core configuration that can regulate the leakage inductance is proposed and described in detail. In order to design the slim size power system for flat panel TV, Two planar transformers applied to LLC resonant converter are connected in series at primary and in parallel by the center-tap winding at secondary. In this paper, a 300W low profile LLC resonant converter was built and tested to verify the proposed planar transformer.

High Frequency Link PCS for Interfacing with Power Utility System

Recently, Power Conditioning System (PCS) tends to require more compact, higher efficiency and power density with better performance. A novel topology consisted of LLC resonant inverter and Low Frequency (LF) cyclo-converter for connecting to utility line is able to meet these requirements. The technical operating analysis is described and 1kW prototype is tested and verified the performances through connecting the 110Vac 60Hz utility line. Efficient results are described.

Power Conditioning System using LLC Resonant Inverter with Two Resonant Tanks

Recently, Power Conditioning System (PCS) tends to become more compact, and tends to require higher efficiency, and higher power density with better performance. To meet these requirements, a novel topology consisted of LLC resonant inverter with two resonant tanks for low power losses and Low Frequency (LF) cyclo-converter for sine wave filtering is proposed. The operating schemes are analyzed and described. A 400W proto product is built, tested and verified the performances by connecting the 110Vac 60Hz utility line.