摘要 在开关电源系统中,电解电容相比较其他元件最易失效,寿命最短。为避免因电容失效造成损失,需要提前预知电解电容工作状态以便及时更换。由于电解电容的电容量C和等效串联电阻ESR（equivalent series resistance）的值可以反映出电解电容性能的衰退程度,因此对电容该参数的在线监测十分重要。本文提出了一种AC/DC DCM反激变换器输出电解电容C和ESR的在线监测方案。通过分析输出电压纹波,推导出C和ESR的计算模型,并据此进行了监测系统设计。最后进行了仿真验证。仿真结果和数据验证了理论的有效性。
Abstract：In the switching mode power supply system (SMPS), the electrolytic capacitors whose lifetime is the shortest are more likely to fail than other components. In order to avoid the losses cause by capacitor failure, it is necessary to know the working state of electrolytic capacitors in advance so as to replace them in time before they fail. The value of C and ESR (equivalent series resistance) can reflect the performance of electrolytic capacitors, thus the online monitoring of the capacitance parameters is very important. In this paper, an online monitoring scheme of output capacitor's C and ESR for AC/DC DCM flyback converter is proposed. The calculation model of C and ESR is deduced by analyzing the output voltage ripple and the monitoring system is designed. Finally, the simulation results and data verify the validity of the theory.
[1] Amaral A R, Cardoso A M.A simple offlinetechnique for evaluating the condition of aluminumelectrolytic capacitors[J]. IEEE Trans.Industry Electron, 2009, 56(8): 3230-3237. [2] Amaral A M R, Cardoso A J M. An automatic technique to obtain the equivalent circuit of aluminum electrolytic capacitors[C]//Proceedings of IEEE Con- ference on IECON, Orlando, FL, 2008. [3] Amaral A M R, Cardoso A J M. Using a sinusoidal PWM to estimate the ESR of aluminum electrolytic capacitors[C]//Proceedings of IEEE Conference on POWERENG, Lisbon, 2009. [4] Ma H, Wang L G.Fault diagnosis and failure prediction of aluminum electrolytic capacitor in power electronic converters[C]//Proceedings of IEEE Con- ference on IECON, Raleigh, 2005. [5] Aluminum Electrolytic Capacitors-Precautions and Guidelines. Nippon Chemi-con, Tokyo, Japan: 3-10.CAT. No. E1001H. [6] Perisse F, Venet P, Rojat G, Retif J M.Simple model of electrolytic capacitor taking into account the temperature and aging time[J]. Electrical Engineering, 2006, 88: 89-95. [7] Kulkarni C, Celaya J, Goebel K, et al.Prognostics health management and physics based failure models for electrolytic capacitors[C]//Proceedings of AIAA, 2012.
2018, Vol. 19 
