基于零输入响应的Cauer型RC网络参数辨识方法

Identification Method for Cauer Type RC Network Parameter Based on the Zero-Input Response

对于封闭的RC网络,其参数不能直接测量,需要根据端口响应辨识网络参数。但对于等效的RC网络,受实际条件限制,端口激励信号是随机变化的,其模型难以建立。提出了一种基于零输入响应的参数辨识方法。在不考虑激励信号的条件下,分析了RC网络参数和零输入响应条件下时间常数之间的关系,得出在一种工况下不能对参数进行辨识的结论。在此基础上,提出通过级联一阶RC网络,在不同的级联网络参数下得到关于待辨识网络参数的约束方程,根据两组不同的约束方程组可辨识出RC参数。以2阶待辨识的CauerⅠ型电网络为例进行了仿真和实验,结果表明所提方法可对Cauer型RC参数进行辨识。然后,将该方法应用在绝缘栅双极型晶体管(IGBT)的Cauer热网络参数辨识中,也取得了较准确的辨识结果。

For the closing RC network, the parameters can＇t be detected directly and its identification relies on response of port. For the existed equivalent RC network, limited by physical constraints, it is difficult to establish the power source model because stimulate signal on port varies randomly. This paper proposes an parameters identification method relying on the zero-input response. This method analyses the relationship between parameters of RC network and time constant in zero-input response without concerning of stimulate signal and get the conclusion that the parameters cannot be identified in one situation. Then, a method cascading one- order RC network is proposed to get different constraint equations about RC parameters under different RC network. Solving two constraint equations of RC network can identify RC parameters. Simulations and experiments are tested and verified on a two-order Cauer I type network which used to be identified as an example in this paper. The results show that this method can identify RC parameter accurately. Then, applying this method in insulated-gate bipolar transistor （IGBT） module also gets the accurate results.