Towards Smart Utilization, Maintenance and Planning of Distribution Transformers Using Smart Meter Data

Distribution utilities regularly face the challenge of overloading in the distribution transformers due to seasonal variations, load growth, and network changes. Additionally nonlinear loads causing harmonics are also contributing to overloading. Sustained overloading leads to increased technical loss, transformer failures, voltage distortion and loss in supply reliability. Availability of quality data for distribution transformers has been a major challenge in distribution operations. Traditionally utilities collect the data of transformer loading from site manually using measuring instruments like millimeter, usually once or twice a day at fixed timings. This is very cumbersome and possible for only a small number of transformers for a small duration only. Besides the quality of data is not good as often the measured value at fixed interval do not coincide with the actual overload. Additionally it is a safety issue for utility personnel the site at odd hours. Hence the practice is not very effective in overload detection. The Smart meter roadmap adopted by TPDDL envisions installation of smart meter for all distribution transformers and consumers in next 5 years. All distributions transformers in TPDDL installed with energy audit smart meters over RF Canopy communication infrastructure in the first phase of Smart meter project. The data from these meters are sent to HES (Head End system) at regular intervals. From HES the data is sent to MDM (Meter Data Management) for analysis and customized reports. The availability of smart meter data for the distribution transformers is creating opportunity to harness host of information like load profile, Phasor, harmonics, unbalance and sustained overloading. These information are helping the operation and maintenance team to assess the condition of transformers, plan maintenance actions, and augment overloaded transformers in the nick of time before significant damage to the transformer may occur. The integration of intelligent information from smart meters with the operation & maintenance practices are unlocking new values for the utilities in multiple ways like