Prefault voltage is one of the most important factors which will affect the assessment of voltage sag frequency in power system. The current stochastic assessment methods usually assume the prefault voltage to be the rated value. In practice, however,the prefault voltage is varying over a range. The range is always changing during peak and valley period everyday under different operating modes. Aiming at the characteristics mentioned above,a mathematical model of the prefault voltage is established with the interval matrix of voltage magnitude and the time weighted matrix,which reflects the three characteristics, that is,peak - valley,time - varying and interval. For the typical characteristics of the prefault voltage,the common process to assess the voltage sag frequency is proposed in detail on the basis of interval algorithm. The proposed method is performed in the actual power grid.It is proved that it needs only one time of interval iteration process. The simulation results indicate that this method is reasonable and effective.
参考文献
相似文献
引证文献
引用本文
张忠;徐培栋.考虑系统峰谷时变区间特性的电压暂降频次评估[J].四川电力技术,2012,35(4):15-20. .[J]. SICHUAN ELECTRIC POWER TECHNOLOGY,2012,35(4):15-20.