中文摘要：

提出一种基于Park矢量模频率特征的新型变压器励磁涌流识别方法。首先分析了变压器内部故障和励磁涌流状态下三相差电流的相对相位关系特征，并讨论了对应的Park矢量模中不同频率分量的特点。在此基础上分别定义Park矢量模中二次谐波相对基波和直流的含量系数，并根据这两个系数大小来识别励磁涌流状态。利用动模实验和数字仿真结果对该方法进行验证分析，并与常规二次谐波闭锁方法进行比较。比较分析结果表明所提方法能有效区分励磁涌流和故障电流，在可靠性上优于常规二次谐波闭锁方法，同时空载合闸于轻微故障变压器时受非故障相涌流的影响小，能够更快地开放保护．

英文摘要：

A new method for transformer inrush currents identitication based on tlae trequency cnaracterlsucs or me/-arKs vector modulus is presented. Firstly, the relative phase relations characteristics among the three-phase differential currents under the conditions of internal fault and inrush are analyzed, and the frequency characteristics of the corresponding Park＇s vector modulus are discussed. Based on the above analysis, the ratios of second harmonic component to fundamental component and the DC component of the Park＇s vector modulus are defined and used to identify the inrush currents. The presented method is verified by the dynamic simulation and is contrasted with the conventional second harmonics restraint method. Analysis results show that the inrush currents and fault currents can be distinguished effectivelyby the presented method, the adverse effect of inrush in non-faulty phase is slight when a faulty transformer is energized, and the performance in reliability and rapidity of the presented method is superior to the conventional second harmonics restraint method.