具有低输入电流纹波和宽范围软开关能力的隔离型高升压电流馈电DC-DC变换器

This paper presents a current-fed isolated, high step-up dc-dc converter that has the low voltage stress on the power switches. The suggested configuration achieves isolation between the input and output using a High-Frequency (HF) transformer. The leakage inductance of the transformer is harnessed to achieve Zero Voltage Switching (ZVS) during power switch turn-on and Zero Current Switching (ZCS) for power diodes across a broad range of operation. Furthermore, within this configuration, proper modulation (Phase Shift Modulation (PSM) or PSM with Pulse Frequency Modulation (PFM) combined with PSM) between the power switches enables the primary power switches to have soft turn-off conditions. Additionally, through this modulation technique, the input inductor experiences an effective frequency that is twice that of the power switches' switching frequency, leading to a reduction in the required size of the input inductor to half. Also, the auxiliary circuit eliminates the voltage spikes across the switches significantly, which occur due to the current difference between the input inductor and the leakage inductance of the transformer. To demonstrate the performance of the converter, the theoretical analysis along with comparisons to other converters are presented. Finally, to validate the theoretical analysis, the proposed converter is constructed to handle input voltages ranging from 20-50 V and operating at constant/variable switching frequency of 100-280 kHz, resulting in an output voltage of 360 V, and a maximum output power of 400 W.