Power factor correction circuit has been used as the harmonic compensation equipment and the effective measure for achieving high power factor. The ever - enhanced attention has been focused to the PFC rectifier in the field of power electronics. In the medium or greater power ratings, the continuous current mode is adopted usually. However, the reverse recovery characteristic of power diode enlarges the switch turning - on loss and the electromagnetic interference is aggravated also. In this paper, a novel capacitive passive lossless snubber is analyzed. It could solve the above issues. It has simple circuit structure and soft switching conditions are satisfied easily. The 500W prototype validates that the efficiency of PFC was improved 1.08% at half load.%功率因数校正(PFC)电路作为谐波补偿装置和提高功率因数的有效措施已成为电力电子技术研究的热点问题,且绝大多数PFC采用Boost电路,在中等及以上功率等级时PFC常采用电流连续模式,而功率二极管由于存在反向恢复特性,开关管的开通损耗被大大增加,电磁干扰加重.本文提出了一种新的电容型无源无损缓冲电路,其能够抑制二极管的反向恢复特性,减小开关管的开通损耗,提高PFC的效率.电路结构简单,软开关实现范围大,500W实验样机验证了PFC在半载时效率能提高1.08％.
展开▼
