摘要
提出用概率求和估计非线性负荷谐波发射水平的新途径.根据非线性负荷投入前后测量值的数字特征建立逆向求和概率模型,通过测量值的x-y分量的n阶矩与Laguerre多项式逼近求和概率密度函数(pdf:probabilitydensity function):用递推算法估计测量统计值各分量的n阶矩,导出矢量和(幅值)的n阶矩,再用参数平方变换合成pdf,引入尺度因子修正截断误差.这种方法求和时不需要各个随机矢量在相位上具有0～2π的概率分布,使用的统计样本值较少.用实际测量值进行的比较分析证明了该方法的有效性.
A new approach for assessing harmonic emission levels from nonlinear loads is proposed with inverse sum of random vectors. The probability models presented are based on the figure characteristics of harmonics from nonlinear load disconnected and connected. The n order moments are used to determine Laguerre polynomials expansion for simulating the sum probability density function (pdf): A recursive algorithm is used to calculate n order moments of measurements on X-Y components. The n order moments of sum of vectors are deduced from it. The scaling factor is introduced to minimize the truncation error. The distributions of random vectors are not required on 0~2π and the number of samples is finite. The calculation results based on field measurement data prove the efficiency of the approach presented.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2005年第7期81-85,共5页
Proceedings of the CSEE
基金
国家自然科学基金项目(51077021)~~
关键词
电力系统
拉盖尔多项式
非线性负荷谐波发射水平估计
负荷预测
Power quality
Laguerre polynomials
Harmonic emission levels
Sum of random vectors
Scaling factor
Truncation error
