Research on Inconsistent Acquisition of Dual AD in Protection Current of Electronic Instrument Transformer

As the key equipment for a new generation of smart substations, the data measurement of electronic instrument transformers is the only basis for the protection calculations performed by the spacer device. Therefore, the accuracy of the measurement is critical to the safe operation of the entire substation. As an entry point from actual project application, this article takes dual-AD sampling data inconsistency of output protection current in the merging unit of the electronic instrument transformer, and based on the specific configuration of the project and the alarm phenomenon, a deep research and analysis was carried out to explain the causes in inconsistency between the dual ADs and the corresponding solutions from the aspects of secondary conditioning circuit, AD sampling and merging unit data processing of the electronic instrument transformer collector. This scheme has been successfully applied in engineering practice. The problem analysis and solutions proposed in this paper provide a further reference for the reliability design of electronic instrument transformers.