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PWM Resonant Converter With Asymmetric Modulation for ZVS Active Voltage Doubler Rectifier and Forced Half Resonance in PV Application

2019; Institute of Electrical and Electronics Engineers; Volume: 35; Issue: 1 Linguagem: Inglês

10.1109/tpel.2019.2914016

1941-0107

Jong-Woo Kim, Moo-Hyun Park, Jung-Kyu Han, Moonhyun Lee, Jih‐Sheng Lai,

Photovoltaic System Optimization Techniques

In photovoltaic applications, many previous research works have focused on pulsewidth modulation (PWM) resonant converters in order to achieve a high efficiency with a wide input voltage range. Conventional approaches utilized symmetric boosting modulation at the secondary side rectifier to obtain a symmetric operation, and they utilized two boosting modes in a switching period. Among various rectifier structures, the voltage doubler structure has a strong advantage due to a small number of components. However, it suffers from serious hard switching losses in the secondary side rectifier. In this paper, a new converter with a novel asymmetrical modulation is proposed and verified. The strong point of the proposed converter is that it eliminates hard switching turn-on losses from the rectifier, while maintaining the minimized number of components. Although the proposed converter adopts an asymmetric modulation, the offset current on the transformer becomes zero inherently. Furthermore, a "forced half resonance" operation of the proposed converter keeps rms current stresses at the same level as conventional converter although it has a higher peak current. Accordingly, the proposed converter achieves a superior efficiency with the minimum number of components at 35-25 V input and 380 V/300 W output specification.