基于双dq变换的引起电压暂降的短路故障分类

Classification of Short Circuit Faults Causing Voltage Sags Based on Double dq Transformation

由短路故障引起的电压暂降是电力系统中最严重的电能质量问题之一。如果能确定引起电压暂降的短路故障类型,则可为电力系统的运行和管理提供参考。提出了基于双dq变换的引起电压暂降的短路故障分类方法。该分类方法先对三相电压信号进行正、负序分解,然后分别对正、负序分量进行dq变换,结合dq变换结果构造出有效值和相位特征量,将二者相结合可判断造成电压暂降的短路故障类型。该分类方法仅需对dq变换得到的结果进行简单的算术和逻辑判断,额外增加的计算量小,可与电压暂降检测相结合,构成统一的电压暂降检测和短路故障分类方法。

Voltage sags caused by short circuit fault are one of the most severe power quality events.It is beneficial to the operation and management of a power system if the short circuit fault types can be identified.A short circuit fault classification method based on double dq transformation is proposed in this paper.The proposed method decomposes the measured three-phase voltage to positive and negative sequences first,and then transforms the two-sequence components into dq frames.Phase angle and root-mean-square value of the voltage are generated as characteristic values to identify the fault types.This method only requires a few logic and simple algebraic calculation,and also can be combined with voltage sag detection to form a unified voltage sag detection and fault classification method.