A LLC type resonant converter based on PWM voltage quadrupler rectifier with wide output voltage

In a typical plug-in electric vehicle onboard charger, the input voltage of the second stage dc/dc converter is usually kept constant while the battery pack voltage varies in a wide range with the change of battery state of charge. In this application, it is extremely difficult to tune the operation of traditional LLC resonant converter close to its resonant frequency. In this paper, a novel pulse width modulated (PWM) LLC type resonant converter based on voltage quadrupler rectifier is proposed. The proposed converter always operates at the resonant frequency and is able to achieve a wide output voltage range. Zero-voltage-switching (ZVS) and zero-current-switching (ZCS) are realized among all power MOSFETs and all power diodes, respectively. A 1.3 kW converter prototype, generating 250 V-420 V output voltage from the 390 V dc link, is analyzed and designed to verify the effectiveness and the advantages of the converter.