电网频率的非正态概率分布特性

Characteristics of Power System Frequency Abnormal Distribution

用随机信号分析的方法研究具有正态分布的随机信号通过几种非线性环节后的概率分布特性,从而对电网中非线性环节对电网频率概率分布的影响进行研究。结果表明电网频率概率分布在调频死区的影响下会呈现双峰现象,在限荷机组及加减机组出力速率、供需平衡的影响下出现偏态分布等。并指出若考虑这些非线性因素的影响,现有的基于电网频率为正态分布基础上制定的相应指标能够更加完善。

The probability distribution with a Gaussian signal passing through a nonlinear function was discussed by the method of stochastic analysis, and the influence of several nonlinear factors on power system frequency probability distribution were presented. The results show that power system frequency probability distribution will present two peaks produced by the influence of dead-band, and it will have an inclined distribution produced by the maximum output power or the different rates of increasing and decreasing powers, etc. As a result, some criteria based on Gaussian distribution of power system frequency would reach more perfection if these nonlinear factors are considered.