A growing problem
Transformers are long-lived assets with a failure rate that increases significantly after ~30 years. In Australia, 41% of medium to large transformer assets are greater than 30 years old. In the USA, the average age of distribution transformers is 42 years and 70% of transmission line and power transformers are 25 years or older.
Lack of visibility drives conservative management.
There is currently minimal monitoring of transformer assets in the electricity distribution network on all but the largest assets due to the current cost and complexity of monitoring systems. This leads to a lack of visibility into the state of health and robustness of assets, which, in turn, drives conservative asset management. Without timely, effective condition analysis, conservative management and heavy investment is needed to avoid catastrophic failure.
This behaviour encourages overspend on the network assets for peace of mind through the early retirement of assets that could have a useful life with proactive management. Commercial and political pressure is now intense to drive down costs and improve infrastructure utilisation.
Market changes require new solutions.
Distributed generation is reshaping network management practices caused by disruptive energy flows. Network engineers need the tools now to make sound decisions regarding transformer health and the ability to handle new and changing loads.
Offline monitoring is sporadic, time-consuming and ineffectual
Existing transformer asset management strategies (originally designed in the 1980s) use sporadic physical inspection, sampling and chemical analysis to generate engineering grade information. This management strategy is costly in labour and testing and is largely ineffective as it fails to take account of the changing temperature, load and other factors that influence transformer health. 1980’s practices are insufficient to support modern automated real time tactical and strategic network management.
 Australian Energy Regulator (AER)