A Novel Dual Integrated LLC Resonant Converter Using Various Switching Patterns for a Wide Output Voltage Range Battery Charger

This paper proposes a novel dual integrated LLC resonant converter (DI-LRC) with a wide output voltage range using various switching patterns. The primary side of the proposed DI-LLC converter consists of two resonant tanks and six switches, while the secondary side consists of a six-pulse diode rectifier. Depending on the switching pattern of the primary switch, the DI-LRC converter is performed by single full-bridge operation with a voltage gain of 1, series-connected full-bridge operation with a voltage gain of 0.5, series-connected half bridge operation with a voltage gain of 0.25, and parallel-connected full-bridge operation with a voltage gain of 2. Accordingly, the proposed DI-LRC converter has four voltage gain curves with different variations and achieves a wider output voltage range than the conventional single voltage gain curve in a given operating frequency range. In this paper, the equivalent circuits derived for each switching pattern are proposed to analyze the operating characteristics of the proposed converter according to each switching pattern, and each Q factor and voltage gain are calculated based on the analyzed equivalent circuit. The performance of the proposed converter and switching pattern is verified using the simulation and experimental results of the prototype battery charger, which is designed to be 4-kW class.

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High Efficiency Isolated On-Board EV Battery Charger Using LLC Resonant Converter

Journal of Engineering Research ◽

10.36909/jer.10637 ◽

2021 ◽

Author(s):

Sevilay Cetin ◽

Keyword(s):

Output Voltage ◽

High Efficiency ◽

Load Condition ◽

Voltage Regulation ◽

Resonant Converter ◽

Battery Charger ◽

Voltage Range ◽

Wide Range ◽

Electrical Vehicle ◽

Llc Resonant Converter

In this study, high efficiency design of an on-board Electrical Vehicle (EV) battery charger is presented. The presented charger has two stages where the first stage is conventional front-end boost converter and the second stage is LLC resonant converter. The basic principles of both stage are discussed and the detailed design procedures are presented in terms of wide range output voltage regulation, wide range load condition, high efficiency and high power density. The presented design approach is tested with a prototype implemented with 2.5 kW output power at 250 V-450 V output voltage range. The peak efficiency of system is obtained as 95.53% at full load condition.

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Bidirectional Resonant Converter for DC Microgrid Applications

Processes ◽

10.3390/pr9091664 ◽

2021 ◽

Vol 9 (9) ◽

pp. 1664

Author(s):

Bor-Ren Lin

Keyword(s):

Electric Vehicle ◽

Output Voltage ◽

Resonant Circuit ◽

Resonant Converter ◽

Battery Charger ◽

Dc Microgrid ◽

Voltage Range ◽

Zero Voltage Switching ◽

Active Devices ◽

Power Operation

A bidirectional resonant converter is presented and verified in this paper for an electric vehicle battery charger/discharger system. The presented circuit can achieve forward and backward power operation, low switching losses on active devices, and wide output voltage operation. The circuit structure of the presented converter includes two resonant circuits on the primary and secondary sides of an isolated transformer. The frequency modulation approach is adopted to control the studied circuit. Owing to the resonant circuit characteristic, active devices for both forward (battery charge) and backward (battery discharge) power operation can be turned on at zero voltage switching. In order to implement a universal battery charger for different kinds of electric vehicle applications, the DC converter is demanded to have a wide output voltage range capability. The topology morphing between a full bridge resonant circuit and half bridge resonant circuit is selected to obtain high- and low-output voltage range operations so that the 200–500 V output voltage range is realized in the presented resonant converter. Compared to the conventional bidirectional converters, the proposed can be operated under a wide voltage range operation. In the end, a 1 kW laboratory prototype circuit is built, and experiments are provided to demonstrate the validity and performance of the presented bidirectional resonant converter.

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