一种新型高增益直流变换器

随着太阳能光伏发电和燃料电池等输出电压较低的新能源电力的广泛应用,大功率和高增益变换器的研究成为电力电子研究领域的热点之一.为实现DC/DC变换器的高增益和高可靠性,提出了一种非隔离无源箝位型交错并联型变换器,其输入并联而输出串联,并试制了1台200W实验装置来验证理论分析的正确性.实验结果表明,采用无源箝位电路可有效回收漏感能量,实现主开关管的软关断和软开通,既避免了附加箝位器件,降低了成本,又达到了与有源箝位电路类似的功效,提高了装置的可靠性.该新型变换器在保持合理占空比的情况下,获得了高增益,降低了变压器的匝比,并使反向恢复问题得到抑制,变换器的效率和功率密度有了一定的提高,磁芯的体积有效减小,证明了这种新型变换器的实用性.

A Novel Type of High Gain DC-DC Converter

With the wide application of new energy of solar and fuel cells whose output voltage is low, researches on high power and high gain converter become one of the focuses of power electronics. To obtained the high gain and high reliability of the DC-DC converter, a novel type of no-isolated passive-clamped interleaving converter based on precharged capacitance unit is proposed, in which the inputs are in series and the outputs in parallel. To test the theory analysis, a 200 W experimental equipment is built. The experimental results indicate that this passive-clamped circuit can receive leakage inductance energy effectively, zero-voltage-switched and zero-current-switched are achieved, which has the similar effectiveness of active-clamped circuit, and the reliability of this device is improved. By using of this new converter, high gain is obtained in the context of suitable duty ratio, transformer turns-ratio is reduced and reverse recovery is restrained, the efficiency is improved, the power density is also improved, and the size of magnetic cores is reduced effectively. So, it is proved that this new converter is novel and practical.