Integrating Monitoring Systems and Power Transformer Protections to Curb Destructive Effects of Quasi-Direct Currents

摘要

This paper dwells upon a power transformer monitoring system designed to track the effects of man-caused or natural quasi-direct currents. The paper demonstrates that such monitoring systems might be difficult to design as it is challenging to isolate the quasi-direct current component in the grounded neutral of a power transformer from other sources of man-caused direct current components in grids. The author-designed system for monitoring power transformers for quasi-direct currents is capable of: continuous 24/7 monitoring; monitoring the readings, checking the status, and changing the settings remotely; remote data collection; direct access to the data of the power transformer control modules. Integrating the monitoring system with the power transformer protections helps track the quasi-direct currents in the neutrals as well as the high-frequency harmonics in the power transformer windings in real time so as to minimize the duration of differential protection blocks when magnetic system saturation is detected.