Resonant Converter with Soft Switching and Wide Voltage Operation

Abstract

A new DC/DC resonant converter with wide output voltage range operation is presented and studied to have the benefits of low switching losses on active devices and low voltage stresses on power diodes. To overcome serious reverse recovery losses of power diodes on a conventional full-bridge pulse-width modulation converter, the resonant converter is adopted to reduce the switching loss and increase the circuit efficiency. To extend the output voltage range in conventional half-bridge or full-bridge resonant converters, the secondary sides of two diode rectifiers are connected in series to have wide output voltage operation. The proposed converter can be either operated at one-resonant-converter mode for low voltage range or two-resonant-converter mode for high voltage range. Thus, the voltage rating of power diodes is decreased. Experiments with the design example are given to show the circuit performance and validate the theoretical discussion and analysis.

Wide Voltage Resonant Converter Using a Variable Winding Turns Ratio

“…The two-stage converters have the drawback of low efficiency, while the series-or parallel-connected converters have more circuit components, which increase the conduction loss and reduce the converter reliability. In [23,24], two full-bridge LLC converters with primary-parallel-secondary-series connection were proposed to achieve wide input or output voltage operation. However, eight power switches and eight diodes are used in this circuit topology.…”

“…Comparing the center-tapped rectifier structure, the voltage double rectifier structure has less conduction losses for rectifier diodes and secondary windings. Comparing the conventional two-stage power converters, parallel-series connected converters, and the other resonant converters in [19][20][21][22][23][24][25][26], the presented LLC resonant converter has a simple circuit structure, a simple control algorithm, and requires fewer power components to achieve wide voltage operation. The description of the presented circuit schematic and operation principle is presented in Section 2.…”

A Comprehensive Overview in Control Algorithms for High Switching-Frequency LLC Resonant Converter

“…In the previous research, various resonant networks have been introduced to utilize the resonance for soft switching characteristics such as L-C series, L-C parallel, LLC, LCL, CLL, CLLC, etc. [1][2][3][4][5][6][7]. Among the resonant networks, the LLC resonant tank has the ZVS capability on the primary side switches, the ZCS capability on the secondary side rectifier, and the small circulating current passing through the transformer [8][9][10].…”

Implementation of a Wide Input Voltage Resonant Converter with Voltage Doubler Rectifier Topology

“…However, the disadvantages of multi stage dc-dc converters have low reliability and more active and passive power components. Two full bridge circuits structure was presented in [12] to overcome limit voltage range problem of conventional resonant converters. However, sixteen power semiconductors are used in this circuit structure.…”

“…Thus, the diode conduction loss can be reduced. The proposed LLC converter has less circuit components compared to the wide voltage resonant converter presented in [8][9][10][11][12][13][14]. Finally, the experimental verifications are provided to demonstrate the performance of the studied LLC resonant circuit.…”