# Transformer Monitoring with Electromagnetic Energy Transmission and Wireless Sensing

## TL;DR

This paper introduces a wireless monitoring system for transformers that detects gas levels and other parameters in real time, helping prevent false alarms and safety risks.

## Contribution

A novel wireless sensing system using electromagnetic energy transmission for real-time transformer monitoring is developed and tested.

## Key findings

- The ETWSD system successfully monitored methane gas concentrations up to 1000 ppm and temperatures up to 90 °C.
- The Android-based app enables real-time data visualization, threshold alerts, and data storage for field workers.
- Field tests confirmed the system's ability to detect and monitor transformer parameters without physical contact.

## Abstract

To ensure stable and normal transformer operation, light gas protection of the transformer Buchholz relay is essential. However, false alarms related to light gas protection are common, and troubleshooting them often requires on-site gas sampling by personnel. During this time, the transformer’s operating state may rapidly deteriorate, posing a safety threat to field staff. To tackle these challenges, this work presents the near-field, thin-sliced transformer monitoring system that uses Electromagnetic Energy Transmission and Wireless Sensing Device (ETWSD). The system leverages external wireless energy input to power gas monitoring sensors. Simultaneously, it employs Near-Field Communication to obtain real-time concentrations of light gases, along with the electrified state and temperature. In field testing conducted on transformer relays’ gas collection chambers, the ETWSD effortlessly monitors parameters within warning ranges, encompassing methane gas concentrations around 1000 ppm, leakage voltage ranging from 0–100 V, and relay working temperatures up to 90 °C. Additionally, to facilitate real-time diagnosis for electrical workers, we have developed an Android-based APP software that displays current light gas concentrations, leakage voltage collection values, and temperature, while also enabling threshold judgment, alarms, and data storage. The developed ETWSD is expected to aid on-site personnel in promptly and accurately evaluating transformer light gas protection error alarm faults. It provides a method for simultaneous, contactless, and rapid monitoring of multiple indicators.