Research Status and Prospective on Current Transformer Saturation Recognition

Saturation identification of current transformers (CT) has always been one of the most important issues in power system relay protection. At present, the saturation phenomenon of CT is widespread in China. In order to accurately grasp the current research status and future research directions of current transformer saturation identification, the author summarizes and classifies the existing methods of current transformer saturation identification: based on CT physical quantities identification method, based on other physical quantities identification method and based on waveform singularity identification method, respectively, introduces the research principles and characteristics of these methods. The research progress of each method is summarized, and the shortcomings of some methods are pointed out. Finally, several key issues in the future of CT saturation identification are summarized, and prospects for future research are put forward.