时域数据转换为频域数据的LCR方法

A LCR Method for Getting Frequency Domain Characteristics Based on Time Domain Data

实际的工业系统中,时域数据较容易得到,但获取系统的频率特性往往比较麻烦。将阶跃输入信号及其输出响应经LCR带通滤波器后,利用LCR滤波器产生的对应数据获取了模型的频域特性,并与理论结果对比,误差较小,从而证明了此方法的有效性。在此基础上,检验了其抗干扰能力,效果较佳。此外,将LCR方法应用到火电厂热工过程的模型辨识中,辨识模型与实际采样数据拟合效果较好,从而间接证明了该方法的可行性。因此,该方法可作为频域分析、辨识等的有效方法。

In practical industries, it is often easier to obtain the time domain data compared with the frequency data. This paper proposes a method to achieve frequency characteristics such as the system gain and phase by putting the step input and output signal into the band-pass filter of LCR. From the comparisons between the data produced by LCR and theoretical calculation, we can find the error is very small. In addition, the anti-disturbance capacity of the method is tested and the results show that it is feasible. Finally, the method is used to get the frequency data of a thermal process in the power plant, and the frequency data is used to identify the thermal process. The results show that the model performances a good fitting effect, and can be used as an effective way to analyze the system stability and identify a mathematical model based on the frequency domain data.