单周期CRM PFC转换器的零交越失真优化设计  

Optimization of zero-crossing distortion in the CRM PFC converter with one cycle control

作　　者：李娅妮[1] 杨银堂[1] 朱樟明[1] 强玮 刘帘曦[1] 

机构地区：[1]西安电子科技大学宽禁带半导体材料与器件教育部重点实验室,陕西西安710071 [2]西安龙腾微电子技术发展有限公司,陕西西安710065

出　　处：《西安电子科技大学学报》2012年第2期108-113,共6页Journal of Xidian University

基　　金：国家自然科学基金资助项目(60725415,60971066);国家863计划资助项目(2009AA01Z258,2009AA01Z260);国家重大科技专项资助项目(2009ZX01034-002-001-005);西安应用材料创新基金资助项目(XA-AM-200814,XA-AM-201010)

摘　　要：为降低总谐波失真提高电源效率,基于单周期临界导通功率因数校正(PFC)转换器,研究了零交越失真现象的优化设计方法.采用周期性自启动定时电路,不论电感电流是否下降到零,及时触发新的开关周期,以避免由于电感反向漏电所引入的导通延迟,从而降低了零交越失真和总谐波失真;在辅助绕组和振荡器之间引入可调分流电阻,对电感电流进行实时监控,调整振荡器输出波形斜率,以控制PWM关断时间,有效改善输入电压零交越点附近的失真现象.输入线电压频率越高,优化效果越好.在50Hz 220 VAC条件下,输入电流为120mA,输出功率为36W,测得优化后的PFC转换器总谐波失真(THD)仅为3.8%,功率因数为0.988,负载调整率为3%,线性调整率小于1%,效率达到97.3%.理论和测试结果均表明:当交流输入线电压接近零值时,优化后系统的零交越失真及THD得到了有效降低,有效芯片面积为1.61mm×1.52mm.To reduce the total harmonic distortion（THD） and increase power efficiency,based on a critical conduction mode（CRM） power factor correction（PFC） converter with one cycle control,the optimization of the zero-crossing distortion is discussed.The introduced periodic self-starting timer could provide a trigger signal to open a new cycle no matter whether the inductor current decreases to zero,thus avoiding the conduction delay produced by the reverse leakage current of the inductor with less zero-crossing distortion and THD.An adjustable shunt resistor connected between the auxiliary winding and the oscillator could regulate the output signal slope of the oscillator to control the PWM turn-off time by monitoring the inductor current of the auxiliary winding real time.It could effectively reduce the current distortion in the vicinity of the input voltage zero-crossing points.The higher the frequency of ac input line voltage,the better the optimization.At 50 Hz 220 VAC,the input current is 120 mA,the output power is 36 W,the experimental THD of improved PFC converter is only 3.8%,the power factor is 0.988,the load adjust rate is 3%,the linear adjust rate is less than 1%,and the efficiency is 97.3%.Both theoretical and practical results reveal that the zero-crossing distortion and THD are reduced efficiently after optimization,especially when the ac line voltage is close to zero.The active die area is 1.61 mm× 1.52 mm.

关 键 词：功率因数校正 零交越失真 单周期 临界模式 总谐波失真 

分 类 号：TN402[电子电信—微电子学与固体电子学] TM46[电气工程—电器]