基于独立随机矢量协方差特性的谐波发射水平评估方法  

Assessment Method of Harmonic Emission Level Based on Covariance Characteristic of Random Vectors

作　　者：惠锦[1] 杨洪耕[1] 林顺富[2] 马豫超[2] 

机构地区：[1]四川大学电气信息学院,四川省成都市610065 [2]西门子中国研究院,上海市200120

出　　处：《电力系统自动化》2009年第7期27-31,共5页Automation of Electric Power Systems

摘　　要：提出了一种基于独立随机矢量协方差特性的用于估计系统侧谐波阻抗及用户谐波电压发射水平的新方法。根据公共耦合点处谐波电流与系统背景谐波只有弱的联系,利用随机矢量协方差特性抵消偏差量方程中背景谐波变动项,解得系统侧谐波阻抗,并跟踪计算用户谐波电压发射水平。根据模式识别向量相似度原理提出影响因子,用于判别背景谐波变动对估计结果的影响程度。通过对实验电路的仿真和现场测试案例的分析,证明了该方法能有效抑制背景谐波变动带来的估计误差,估计结果更为合理。This paper reports a new method to estimate the system-side harmonic impedance and the customer-side harmonic voltage emission level at the point of common coupling （PCC） in a power grid based on the covariance characteristic of random vectors. Since the harmonic current at the PCC commonly exhibits negligible dependence on the system-side harmonic current, the fluctuation level of the system-side harmonic current in the deviation formulation can be eliminated by using the covariance characteristic of random vectors, and the system-side harmonic impedance and the customer-side harmonic voltage emission level can be calculated. In addition, an influence factor that represents the influence degree of the fluctuation of the system-side harmonic is introduced based on the similarity principle of pattern recognition theory to yield a confidence reference of the estimation results. Based on the analysis results of laboratory simulation and field test cases, it proves that the proposed method is effective to eliminate the estimation error caused by the fluctuation of the system-side harmonic current.

关 键 词：电能质量 谐波发射水平 谐波阻抗 随机矢量协方差 

分 类 号：TM711[电气工程—电力系统及自动化]