基于熵权法的电压暂降严重程度综合评估方法

Comprehensive Evaluation Method of Voltage Sag Severity Based on Entropy Coefficient Method

提出了一种基于熵权法的节点电压暂降严重程度评估方法。首先,基于IEC61000-2-8表格确定评价指标及其等级划分;然后,采用层次分析法与权值函数法分别计算持续时间与幅值影响度,进而假设持续时间与幅值相互独立,定义了复数形式的电压暂降影响度,并以标准化模值量化影响度的大小;最后,通过熵权法将基于层次分析法与基于权值函数法的电压暂降影响度赋权求和得到基于熵权法的电压暂降综合影响度。使用所提出评估方法分析某城市电网电压暂降监测数据的结果表明,通过熵权法将层次分析法与权值函数法结合,计算结果较使用单一方法更为合理,所提电压暂降综合影响度指标可以更全面地描述电网中典型监测节点的电压暂降严重程度。

In this paper,an evaluation method of voltage sag severity is proposed based on entropy coefficient method.First of all,based on IEC61000-2-8 statistical tables,evaluation index and hierarchy classification are determined.Then,the influence degree of duration and amplitude is calculated based on the analytic hierarchy process（AHP）and weight function method,and it is further assumed that the duration and amplitude are independent of each other,by which influence degree of voltage sag is defined in the plural form,and influence degree is quantified by standardized modulus value.In the end,the comprehensive influence degree of voltage sags is obtained by entropy method through weighting summing influence degree of voltage sag by combining analytic hierarchy process and weight function methods.The analyzing results of monitoring data of the grid voltage sag for a certain city obtained by using proposed method show that the calculation results obtained by combing analytic hierarchy process and weight functions method through entropy coefficient method are more reasonable than that obtained by single method,and the proposed comprehensive effect index of voltage sag can more fully describe the voltage sag severity of the typical monitoring stations in power grid.