基于波形分析的电流互感器局部暂态饱和检测方法

A Method for Detecting Local Transient Saturation of Current Transformers Based on Waveform Analysis

为避免由于电流互感器局部暂态饱和故障引起的差动保护误动行为,提高暂态饱和状态的检测精度,引进波形分析技术,设计一种针对电流互感器局部暂态饱和的全新检测方法。根据电流互感器在运行过程中二次电流波形图的数学形态,掌握互感器的运行工况,获取基于波形分析的电流互感器二次电流暂态信息;通过电流互感器局部暂态相位偏移饱和识别,完成暂态饱和状态的检测。以某电力系统为例,使用EMTDC/PSCAD软件,在终端建立电流互感器局部暂态饱和仿真模型,设计对比实验。实验结果表明:设计的检测方法应用效果良好,该方法的检测结果更加可靠,可以通过此种方式,降低由于互感器故障造成的电力系统供电服务异常。

In order to avoid differential protection misbehavior caused by current transformer local transient saturation faults,and to improve the detection accuracy of the transient saturation state,waveform analysis technology is introduced to design a new detection method for the local transient saturation of the current transformer.According to the mathematical form of the secondary current waveform of the current transformer in the process of operation,the operating conditions of the transformer can be grasped,and the transient information of the secondary current of the current transformer based on waveform analysis can be obtained;and through the identification of the local transient phase offset saturation of the current transformer,the detection of transient saturation can be completed.A power system,for example,will use EMTDC/PSCAD software to establish a current transformer local transient saturation simulation model at the terminal and design a comparison experiment.The experimental results show that the application of the designed detection method is effective,the detection results of this method are more reliable,and the power system power supply service abnormality due to transformer failure can be reduced in this way.