High‐frequency single‐switch PFC with frequency‐modulation controlled class‐E2 converter

Abstract

This paper presents a single-switch zero-voltage switching (ZVS) power-factor correction converter based on the class-E 2 converter at 1 MHz switching frequency. A design method for ensuring the ZVS for the entire line-voltage period is proposed. By visualising the ZVS region in the parameter space, circuit parameters can be easily obtained to achieve the ZVS for the entire line-voltage period. Additionally, a closed-loop controller is applied for achieving a high power factor, low total harmonic distortion of the input current and output voltage regulation. The experimental circuit achieved the ZVS in the entire line-voltage period against load variations. As a result, the implemented converter achieved the same level of power-conversion efficiency as the 100-kHz power-factor correction converters and a high power factor with low total harmonic distortion, which denoted the effectiveness of the proposed design method. INTRODUCTIONAC-DC power supplies with power factor correction (PFC) are used in a wide range of applications. The applications of AC-DC converters include battery charger [1-6], light-emitting diode (LED) lighting [7-16], electric vehicle (EV) [17, 18] and laptop computer [19, 20]. A two-stage PFC power converter [1, 2, 21-24] is a series connection of an AC-DC converter for correcting PF and a DC-DC one for regulating the output voltage. The two-stage AC-DC converter requires at least two power switches and two individual controllers, which leads to a high cost and a large volume. On the other hand, a single-stage AC-DC converter combines the PFC stage and the voltageregulating one into a single converter [3-16, 20, 24-31]. Therefore, single-stage converters have a small component number and achieve low costs compared with two-stage converters, and are often applied for space-constrained applications such as battery chargers [3-6]. Traditional converter topologies, such as boost [11, 12], buck [13], buck-boost [13, 14], and Flyback converters [9, 10],This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Load‐independent inverse class‐E ZVS inverter and its application to wireless power transfer systems

“…The resonant power converters with mega‐hertz‐order operating frequency have been attracted many researchers and developers [1–9]. High‐frequency operations contribute to small circuit volume, high power density, and lightweights of the converters.…”