基于SG6841的反激式开关电源动态特性研究  

Research on dynamic characteristics of SG6841-based flyback switching power supply

作　　者：王竞远 李建春[1] 翟天祺 吴明剑 WANG Jingyuan;LI Jianchun;ZHAI Tianqi;WU Mingjian(Beijing Institute of Space Control Instruments,Beijing 100854,China)

机构地区：[1]北京航天控制仪器研究所

出　　处：《自动化与仪器仪表》2019年第11期9-11,共3页Automation & Instrumentation

摘　　要：在反激式开关电源的控制环路中,常采用光耦SFH615和稳压二极管TL431对电路的输出电压进行采样然后送至电源管理芯片SG6841构成闭环控制回路。实际上开关电源硬件回路中的各项补偿参数,均是通过硬件反复调试得到的经验参数。但因影响电路闭环的因素较多,实验得出的参数不具有代表性。若改变设计标准则实验结果无法复现,故引入小信号模型对控制环路进行分析,并用频响分析仪测出系统闭环bode图。结果表明,该反激式开关电源具有良好的动态特性。In the control loop of flyback switching power supply,photocouple SFH615 and voltage stabilizing tube TL431 are often used to sample,and then sending to the control chip SG6841,a negative feedback loop is formed.The stable dynamic compensation parameters of switching power supply are determined by repeated tests.However,the test results are no longer applicable if the design requirements are changed without universality due to many factors affecting the stability.Therefore,a small signal model is introduced to analyze the control loop,The closed loop bode chart of the system is measured by frequency response analyzer.The results show that this method has good auxiliary performance.

关 键 词：SG6841 SFH615 TL431 反激式辅助电源 

分 类 号：TP202[自动化与计算机技术—检测技术与自动化装置]