On-line supervision of transformer on-load tap changer

We show in this paper that the observed tendency to improve the operation reliability of the tap changer, justifies “on-line” monitoring of that component. We present the hardware and software solutions based on OLTC drive power comparison, which are especially useable for relatively aged transformers. We present the constructed device and its abilities. We explain that the integration of the applied methodology with an expert system is the best approach. We describe how the expert system forms warnings, alarms and directions which are based on reasonable factors. We will present a few registered diagrams signaling the existence of OLTC incorrectness or failures.