Digital transformation of power-transformer solid-insulation drying process

The presence of moisture in the insulation system is detrimental to the performance of power transformers. Traditional solid insulation drying process in the transformer industry uses empirical recipes to ensure low levels of moisture but often require long cycle times firstly because active parts with the heaviest and thickest insulation assemblies, which are the hardest to dry, must be covered by the recipes, and secondly because no practical moisture sensor exists that can monitor moisture along all the stages of the process. In addition, process data and operating history are usually recorded by hand which is prone to human errors and difficult to analyze. Optimization of the drying process can be achieved through the Internet of Things, Data Analytics, and other emerging technologies. As an example of the evolution of transformer manufacturing practices, this paper describes a method for monitoring the drying process of solid insulation considering Internet of Things and analyzing the data aiming to optimize cycle times ensuring low moisture levels. The devised architecture, the software design, as well as the Internet of Things based monitoring system are presented following the main requirements of the power transformer manufacturing industry.