中文摘要：

高压直流输电和地磁感应电流引起的直流偏磁现象日趋严重,分析其对电流互感器暂态传变特性的影响十分必要。通过建立等效分析模型,针对直流偏磁及故障起始角对于电流互感器暂态传变特性,特别是对起始饱和时间的影响进行了详细的推导和分析。通过MATLAB程序对某实际电网中运行的电流互感器暂态传变特性参数进行计算,得出偏磁电流大小与起始饱和时间、二次电流的基波和2次谐波的定量关系。分析结论为了解电流互感器在偏磁条件下的工作状况以及继电保护装置的整定提供了参考。

英文摘要：

As the DC bias caused by HVDC power transmission and geomagnetic induction becomes more serious,its effect on the transient transferring characteristics of CT（Current Transformer） should be analyzed.An equivalent analysis model is built and the effects of DC bias and initial fault angle on the transient transferring characteristics of CT,especially the initial saturation time,are deduced and analyzed in detail.The transient transferring characteristic parameters of an operating CT in an actual power grid are calculated by MATLAB programs and the quantitative relations between the DC bias current and the initial saturation time,between the DC bias current and the fundamental of secondary current and between the DC bias current and the second-order harmonic of secondary current are obtained. The conclusions of analysis provide the references for understanding the working state of CT with DC bias and for the setting of relay protections.