考虑不确定区域的敏感设备电压暂降兼容能力分析

Analysis of Voltage Sag Compatibility Capability of Sensitive Equipment Considering Uncertain Area

研究敏感设备的电压暂降兼容能力是十分重要的问题。对传统敏感设备兼容能力分析方法进行了理论研究,分析了其存在的不足,并提出了一种考虑不确定区域兼容概率的敏感设备电压暂降兼容能力分析方法,兼顾了电网侧电压暂降事件发生的随机性和敏感设备发生故障的不确定性,分别建立电网侧和设备侧的概率分布模型,并选取合适的分布函数建立设备侧和电网侧的故障概率分布函数,进而计算设备耐受曲线不确定区域中的兼容概率和总兼容次数,更加准确地描述了敏感设备的耐受特性,从而较大程度上提高了评估精度。通过实例分析,并与传统拟合方法和兼容能力分析方法作比较,建议采用改进最大熵法对设备侧和电网侧的故障概率分布函数进行拟合。所提方法可为电网、治理厂商和敏感设备用户防治电压暂降问题提供有力的理论依据。

It is very important to study the voltage sag compatibility capability of sensitive equipment.In this paper,the traditional compatibility capability analysis method for sensitive equipment is studied theoretically,and its shortcomings are analyzed.In addition,a method for analyzing the voltage sag compatibility capability of sensitive equipment considering the compatibility probability in uncertain area is proposed,which takes into account the randomness of voltage sag events on the grid-side and the fault uncertainty of sensitive equipment.The probability distribution models on the grid-and equipment-side are established,respectively,and the corresponding fault probability distribution functions are formulated by selecting appropriate distribution functions.Furthermore,the compatibility probability in the uncertain area of voltage tolerance curve and the total compatibility times are calculated,which gives a more accurate description of the tolerance characteristics of sensitive equipment and thus improves of the evaluation accuracy to a greater extent.Through the analysis of a real example and compared with the traditional fitting methods and compatibility capability analysis method,it is suggested that the improved maximum entropy method should be used to fit the fault probability distribution function on the equipment-and grid-side.The proposed method can provide a strong theoretical reference for the prevention and management of voltage sags for power grid,related manufacturers and users of sensitive equipment.