Research on Intelligent Identification Method of CT Secondary Circuit Virtual Connection Based on Harmonic Current Spectrum Analysis

The virtual connection of the secondary circuit of current transformers will generate risks such as heating, inaccurate measurement, and protection (refusal) maloperation, which not only endanger electrical equipment but also pose a huge threat to personal safety. It must be detected and eliminated early. In response to the problems and shortcomings of existing open circuit monitoring devices for current transformers, this paper proposes an intelligent identification method for virtual connections in the secondary circuit of current transformers based on harmonic current spectrum analysis. By analyzing the harmonic content of the secondary circuit, it can determine whether virtual connections have occurred. The virtual connection recognition device has a simple structure and high sensitivity and accuracy in judgment. It can recognize various forms and degrees of virtual connections of current transformers, making the system operate more safely and reliably.