【摘要】 针对电力系统中具有不同相角分布时随机谐波矢量(电压和电流)求和问题,采用最大熵原理求取谐波矢量和幅值(简称和值)的概率密度分布。通过各随机矢量X、Y正交分解后的统计特征(各阶矩)合成得和值的统计特征,由最大熵原理仅需4阶矩就能很好地逼近矢量和值的概率密度函数PDF(Probability Density Function),进而获得相应的95%概率值,避免了递推高阶矩所带来的误差;且求和时不需要各个随机矢量在相位上具有0～2π的均匀概率分布,适用于小样本情况。最后用实际测量值进行的对比分析验证了该方法的有效性。更多还原

【Abstract】 This paper presents a new method by using principle of maximum entropy to obtain the probability density distribution of sum of random harmonic vectors(voltage or current) whose phases have different probability distribution functions in a power system.Several vectors are decomposed with X-Y axis.Obtaining the summation of random vectors by that of their high order moments and through the iteration of moments of given vectors’ X-Y axis components,the PDF of the sum of vectors is obtained by using principle of maximum entropy and only needing 4-order moments,and then obtaining the probability value of 95% of the sum of vectors,avoiding the error of iteration of calculating the high moments.The kind of summation method does not require the probability distribution of each random vector is within the interval(0,2π) in phase angle,so less statistical samples value is to be used.The analysis on practical measured values and comparison with other method prove that the proposed method is effective.更多还原