Design and implementation of a low cost Distribution Transformer monitoring system for remote electric power grids

The main utility company in Uganda owns and operates over 8,000 Distribution Transformers (DTs) and loses over 700 DTs annually due to various reasons. At present, the distribution company uses a peak load analysis scheme to determine the transformer load conditions and effect the load growth, which is a tedious task and doesn´t solve the problem of DT failure resulting from; load unbalance, over load, vandalism among others. In order to achieve better DT performance, a low cost monitoring system was sought as most commercially available systems with SCADA integration potential are costly. This paper presents a distribution transformer (DT) monitoring system designed and implemented with GSM functionality capable of monitoring load variations and relaying information concerning transformer load state. Furthermore, the system was able to store and analyse information received from the monitoring device concerning the transformer state. The system was able to benchmark the DT measurements to abnormal operation and take action before failure and was built at less than $200. The cost can be further lowered with large scale production. The future system will be integrated with a condition monitoring plug to ensure loss of life prediction.