Online Transformer Monitoring System DRYCORE DC-5M

The online transformer monitoring system DRYCORE DC-5M is designed to provide continuous, real-time monitoring of transformer condition and to eliminate the main drawback of traditional diagnostics, which are based on periodic—and therefore delayed—measurements of oil and insulation parameters. At large modern industrial facilities, an average of up to six power transformers fail each year, and up to half of these failures could be prevented with timely moisture measurement and dissolved gas analysis (DGA) in transformer oil. Moisture is one of the primary factors driving insulation degradation: it sharply reduces dielectric strength, accelerates paper aging, and creates conditions for partial discharges. Because moisture concentration can change within a matter of hours due to temperature fluctuations, traditional oil sampling has long ceased to be a reliable diagnostic tool. This is why an online transformer monitoring system has become a core element of modern defect prevention strategies.

Challenges and the nature of insulation defects

Operational experience with transformers and autotransformers rated at 110 kV and above shows that reliability in most cases is determined by the condition of the oil-barrier insulation system. Localized weakened areas in insulation materials become sources of ionization processes that, over time, lead to partial discharges, which in turn result in hazardous electrical defects. Such defects can develop over many years, while standard scheduled measurements performed at fixed intervals are unable to capture early signs of deterioration. The most dangerous defects include inter-turn short circuits and creeping discharges in solid insulation, which almost always develop covertly, even though they are accompanied by changes in oil properties.

The most hazardous defects include:

• inter-turn short circuits in windings;

• creeping discharges in solid insulation;

• ionization processes leading to electrical breakdown.

Analysis shows that the most reliable detection occurs at the pre-breakdown stage, when processes have already been activated but have not yet transitioned into an internal short circuit. However, without continuous parameter recording, such detection is practically impossible. For this reason, an online transformer monitoring system becomes a tool capable of identifying the development of emergency operating conditions in a timely manner, even when conventional indicators remain within acceptable limits.

Online Transformer Monitoring System DRYCORE DC-5M: operating principle

The DRYCORE DC-5M system operates directly next to the transformer, forming a closed-loop oil circulation circuit. It draws oil from the lower part of the transformer tank, passes it through the sensor module, and returns it to the upper part of the transformer. One measurement cycle is performed every minute, after which all data are transmitted to a cloud server. There, in accordance with the DRYCORE methodology, additional parameters are calculated, making it possible to assess not only the condition of the oil but also the condition of the solid insulation. This approach enables an unlimited number of measurements and creates a digital representation of transformer condition with a level of accuracy that is completely unattainable with periodic monitoring. The system determines moisture content in the upper and lower oil layers, calculates moisture in the solid insulation, evaluates dielectric strength, oil quality index, and a number of additional characteristics that together form a comprehensive diagnostic model of the transformer.

Remote access and analytical capabilities

Users can view data from anywhere in the world via a password-protected web platform. All parameters are presented in the form of graphs, charts, and digital indicators, while the transformers themselves are displayed on an interactive map. This format allows analysis of equipment behavior over any selected time period, identification of degradation trends, forecasting of defect development, and maintenance planning based on actual condition rather than a calendar schedule. As a result, operating costs are significantly reduced, safety is improved, and equipment service life is extended.

Technical parameters of DRYCORE DC-5M in practical operation

The system capacity is 7.9 gallons per hour, providing sufficient circulation rate for accurate measurement and stable parameter control.
The online transformer monitoring system DRYCORE DC-5M makes it possible to significantly reduce the number of failures, lower diagnostic and laboratory analysis costs, avoid unplanned outages, and extend transformer service life by several tens of percent. Thanks to remote access, advanced analytics, and the ability to operate continuously over long periods, this solution makes transformer operation predictable, controllable, and economically efficient. This type of online transformer monitoring system enables the transition from reactive, post-failure repair to preventive condition-based asset management, which is the foundation of modern digital power engineering.