Development of Multiresolution Analyzer for Nonlinear Phenomena in Power Systems in Order to Estimate the Insecure Condition

在输电网络中，由于多台发电机之间通过线路电抗相互作用而产生潮流波动。潮流波动包含了系统运行不连续所产生的隐含的非线性信号。本课题的研究目的是寻找一个能反映电力系统动态行为的关键参数，并研制出一种多分辨分析仪的原型系统来估计非线性信号以识别系统的不安全状态。主要研究成果如下：(1)利用4个数字信号处理器构成了电力系统潮流波动分析仪的样机。通过基于线性时不变模型的辨识算法得到的关键参数，可以对电力系统的不安全状态进行估计。此外，如果考虑电力系统的非线性动态特性，精度也得到了提高。(3)利用东北电力公司的电力系统模拟仿真器对样机进行了实验测试。试验结果表明，该样机可以检测到系统阻尼随发电机出力的增加而恶化。(4)研究了东北电力公司基于GPS的测量系统同步采集的多点潮流波动的人机界面。

In electric power transmission network, the power flow fluction occurs by the interaction among multiple generators through the line reactance. The power flow fluctuation include hidden nonlinear signal which arise from the discontinuity of system operation. Aim of our research project is focused to find out a key parameter that will show the dynamic behavior of power systems and to develop a prototype of the multiresolution analyzer to estimate the nonlinear signal for identification of the system insecure condition. The major results obtained through the study are as follows.(1) A prototype of the analyzer for electric power flow fluctutation is configured by 4 digital signal processors. This allows parallel processing in a sufficient high speed for the on-line operation.(2) We can estimate the insecure condition of power system by a key parameter obtained by an identification algorithm based on a linear time-invariant model. In addition improvement of the accuracy is confirmed if the nonlinear dynamic characteristics of power systems are taken into account.(3) Experimental test of the prototype analyzer was performed by using a power system analog simulator at Tohoku Electric Power Company. The results of test show that the deterioration of system damping according to the increasing generator output can be detect by the prototype.(4) Man machine interface has been studied which visualizes the power flow fluctuations synchronously collected at multiple locations by the GPS based measurement system of Tohoku Electric Power Company.