ＰＴＣ元件开关特性建模与测试方法研究

由于ＰＴＣ元件具有良好的开关特性，ＰＴＣ元件已被大量用于过流保护，彩电消磁以及电机启动等工业领域，为了确保产品的质量，必须对ＰＴＣ元件的开关特性进行和评估，本文首先通过理论分析，建立ＰＴＣ元件开关特性的微分方程模型，利用数值方法进行求解，实现了ＰＴＣ开关特性的仿真，然后以理论分析为基础，构造了两种对开关特性参数－动作时间进行测量的方法，（１）硬件信号调节方法，以ＡＣ－ＤＣ转换电路为基础，（２）软件信号处理方法，以希尔伯特变换为基础，理论分析及袂验验证表 明，这两种方法的均能有效地测量ＰＴＣ元件的动物时间参数，其中第（２）种方法的测量精度较高，但同时测试费用也较高。

Modeling and MeasuringMethods ofSwitching Characteristics of PTC Elements

Thanks to their switching characteristics, PTC elements have been used more and more broadly in over-current protection, electromotor starting, etc.. In order to ensure the quality of those industrial products using PTC elements, it is necessary to test and evaluate the switching characteristics of PTC elements before assembling. In this paper, firstly, through theoretical analysis, the differential equation model of the switching process of PTCs is built, which can simulate the switching behavior effectively and accurately. Then, two parameter measuring methods are developed, one is hardware signal condition method, mainly based on a AC to DC transition circuit; The other is software signal processing method, mainly based on Hilbert transform. Theoretical analysis and experimental results show that both the two methods can measure the switching characteristic parameter effectively, while the latter can achieve higher accuracy than the former one with relatively higher cost.