电流互感器暂态饱和的延时计算分析及改进措施

当电网中一次电流包含有长时间的非周期分量时,可能会使电流互感器的铁芯深度饱和,但饱和出现的时间有时延,且时延大小与系统一次时间常数、互感器二次回路时间常数、非周期分量幅值、CT的工作循环以及CT的暂态面积系数等有关。文中通过实例计算分析了CT暂态延时饱和过程,论述了减小互感器饱和对保护装置影响的改进措施。

Analysis and Improvement Measures of Transient Saturation Time-delay of Current Transformer

When primary current contains long non-periodic components in power grid,it may make the current transformer core saturate.But the saturation has time-delay,the size of which is in connection with the system once time constant,transformer secondary circuit time constant,the non-periodic components amplitude,CT work cycle,CT transient area coefficient and so on.Through the example,this paper calculates and analyzes the process of CT transient saturation time-delay,and discusses the improvement measures to reduce the influence of transformer saturation on protection devices.