基于自适应滑动窗的电力信号扰动分析

针对子空间旋转不变性算法对非平稳电力信号扰动性能较差,文章提出了一种基于自适应滑窗时频分析方法。该方法首先根据非平稳电能质量扰动信号特征,采用自适应滑窗与ESPRIT算法对数据进行处理,检测出扰动信号频率和幅值信息。实验结果表明,文章提出的方法适合动态电力信号的检测,具有实际应用前景。

基于最小极大法的电力扰动信号压缩

作者对电力扰动信号的时—频局部特征进行了分析,针对信号压缩过程中的阈值选取问题提出了最小极大法。按照最小极大法选取阈值并压缩信号分解的各细节版本,信号的时—频局部特征不会丢失。对影响压缩效果的分解层数和频带重叠问题进行了研究,并提出了有效的解决策略。测试结果表明提出的压缩方法可以获得很好的压缩效果,在特征信息不丢失、基频分量不失真的情况下,压缩比仍比较高,是解决电力扰动信号压缩问题的一种有效方法。

基于动态测度的电能质量监测系统

提出了一种基于以太网的大型工业园电能质量监测系统,系统下位机以基于ARM+DSP的电能质量监测终端为核心,实现对电能质量的在线监测、记录和分析。详细阐述了系统的关键技术,重点介绍了利用动态测度算法对电力扰动信号进行精确的估算,并通过试验室测试和软件仿真验证了系统的有效性。该系统具有低成本、高速度、高可靠性的特点,对大型工业园智能电网高级测量体系的建设具有重大实际意义。

A novel stabilization approach for small signal disturbance of power system with time-varying delay

Small signal instability may cause severe accidents for power system if it can not be dear correctly and timely. How to maintain power system stable under small signal disturbance is a big challenge for power system operators and dispatchers. Time delay existing in signal transmission process makes the problem more complex. Conventional eigenvalue analysis method neglects time delay influence and can not precisely describe power system dynamic behaviors. In this work, a modified small signal stability model considering time varying delay influence was constructed and a new time delay controller was proposed to stabilize power system under disturbance. By Lyapunov-Krasovskii function, the control law in the form of nonlinear matrix inequality （NLMI） was derived. Considering synthesis method limitation for time delay controller at present, both parameter adjustment method by using linear matrix inequality （LMI） solver and iteration searching method by solving nonlinear minimization problem were suggested to design the controller. Simulation tests were carried out on synchronous-machine infinite-bus power system. Satisfactory test results verify the correctness of the proposed model and the feasibility of the stabilization approach.