电流互感器饱和对保护影响的仿真研究

Emulation Study on the Relay Protection is Affected by CT Saturation

目前广州地区10kV系统的短路电流水平较过去有了很大程度的提高,从而使电流互感器可能承受的短路电流远大于其一次额定准确限值电流,短路情况下电流互感器是否会发生饱和,是否会因此造成保护的不正确动作。这些是目前工程中急于解决,却难以定量分析的问题。本文通过建立电流互感器的EMTP仿真模型,定量分析了短路电流和二次负载变化对电流互感器饱和及保护测量值的影响及规律。

Comparing with the case before, the short circuit current level of 10kV system in Guangzhou city now has been advanced in a high grade, thereby the short circuit current to be born by CT would be over its first rated nicety limit current far away, and then some questions, such as if the saturation of CT could happen in short circuit, if the relay protection could act wrong from it etc. need to be solved urgently, but they are also difficult to make quantitative analysis. In this paper, constructing an EMTP emulation model of CT, the author made a quantitative analysis on that short circuit current & the variety of secondary burden give an effect to the saturation of CT & the measuring of relay protection and their orderliness.