节能照明电器中薄膜电容的特性和选择

The Properties and Selection of Film Capacitors in the Energy Saving Lightings

从电容的等效电路,分析了与薄膜电容的失效密切相关的参数——损耗因子tanδ、额定电压VR、允许交流电压有效值Vrms、允许的交流电流有效值Irms、允许的电流峰峰值IP-P,从它们的电气特性可以看出薄膜电容的参数不是常数,而是信号频率f、工作温度T和电容的表面积A等的函数,给出了Vrms-f、IP-P-f、IP-P-C曲线,通过这些曲线能够正确地选择薄膜电容,从而避免它们在节能照明电器中的失效。

On the basis of capacitor＇s equivalent circuit, we analyze film capacitor＇s parameters： dissipation factor tamS, rated voltage VR, permissible alternating voltage V permissible alternating current I permissible current peak-peak value Ip.p, which are related to the film capacitor＇ s failure closely. Their electrical properties show these parameters are not constant but functions of signal frequency f, operating temperature T, surface area A, etc. Also we get V -f, Ipp-f, Ip_p-C curves for the film capacitors. These curves help us select film capacitor correctly and avoid its failure in the energy saving lighting appliance.