摘要
介质损耗角检测是判断变压器绝缘状况的有效手段之一,而准确地提取基波电压和电流信号是检测介质损耗因数的关键。引入一种处理非线性、非平稳信号的经验模态分解法(empirical mode decomposition,EMD),分解提取信号的固有模态函数(intrinsic mode function,IMF)分量和基波分量,利用正弦波参数法得出介质损耗角,实现介质损耗因数的准确检测。在分析tanδ的在线监测数据时,利用EMD提取的直流分量可以反映变压器绝缘设备的介质损耗因数变化趋势,因而可以作为故障诊断的依据。仿真结果表明,该算法无需预知原信号的先验信息,受谐波和噪声的影响较小,具有更强的自适应能力,能有效提高介质损耗角检测和趋势提取的准确度。仿真结果还验证了该方法的可行性与有效性。
Dielectric loss angle measurement is one of the effective means to evaluate transformer insulation conditions. The key to the dielectric loss angle measurement is to extract fundamental waves of voltage and current signals precisely. In order to detect transformer dielectric loss angles accurately, a novel method for processing nonlinear and non-stationary signals, which is called empirical mode decomposition （EMD）, was introduced, the intrinsic mode function （IMF） component and the fundamental wave of the signals were extracted, and the dielectric loss angle was obtained by applying sine parametric method. The direct current component obtained by EMD, which can reflect the variation trend of insulation systems, was adopted as the basis of fault diagnosis in the analysis of the on-line monitoring data of rantS. Simulation results show that the proposed method does not need the priori information and can be less affected by harmonics and noises. Because of its stronger self-adaptability, the proposed method can improve the accuracy and stability of dielectric loss measurements effectively. The simulation results also verify the feasibility and effectiveness of the method.
出处
《中国电力》
CSCD
北大核心
2011年第2期23-26,共4页
Electric Power
关键词
介质损耗角
经验模态分解
固有模态函数
正弦波参数法
dielectric loss angle
empirical mode decomposition
intrinsic mode function
sine parametric method
