Optimizing Accuracy in Metering Cubicles: Case Studies of Online Error Correction

Metering Cubicles are used for energy and maximum demand measurement of the High Tension (HT) as well as Low Tension (LT) industrial consumers. The revenue of Power Distribution Utilities (PDUs) is based on the performance of these cubicles. The HT Metering Cubicle contains current transformers (CTs), potential transformers (PTs), and a Digital Energy Meter (DEM). However, in LT Metering Cubicle PTs are not connected. The rating of CTs and PTs depends on the contract demand of consumer load and connection level respectively. The accuracy of the energy and maximum demand measurement depends upon errors of CTs, PTs, and DEM. As the accuracy class of these components increases, metering cubicle cost also increases. The objective of this article is to demonstrate the application of an error correction algorithm that could be used to convert low-accuracy class metering cubicles into high accuracy class. Two case studies concerning HT and LT consumers are reported to prove the effectiveness of this technique.