Online Transformer Monitoring System (DRYCORE DC-5M)

The DRYCORE DC-5M online transformer monitoring system is designed to provide continuous, real-time monitoring of transformer condition and to eliminate the main disadvantage of conventional diagnostic methods, which are based on periodic—and therefore delayed—measurements of insulating oil and solid 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) of transformer oil. Moisture is one of the primary factors contributing to insulation degradation: it significantly reduces dielectric strength, accelerates paper degradation, and creates conditions for partial discharges. As moisture concentration can change within a matter of hours due to temperature fluctuations, conventional oil sampling is no longer a reliable diagnostic tool. This is why online transformer monitoring systems have become essential to modern defect prevention strategies.

Challenges and the nature of insulation defects

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

The most hazardous defects include:

• turn-to-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 degradation processes have already been initiated, but have not yet developed into an internal short circuit. However, without continuous parameter monitoring, such detection is not feasible. 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 right next to the transformer, forming a closed-loop oil circulation circuit. It draws oil from the bottom of the transformer tank, passes it through the sensor module, and returns it to the top 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 the transformer condition with a level of accuracy that is unattainable when periodic monitoring is applied. The system determines moisture content in the top and bottom oil layers, calculates moisture content in the solid insulation, evaluates dielectric strength, the oil quality index, and a range of additional parameters that collectively form a comprehensive diagnostic model of the transformer.

Remote access and analytical capabilities

Users can access 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 transformers are displayed on an interactive map. This format enables analysis of equipment behavior over any selected time period, identification of degradation trends, prediction of defect development, and maintenance planning based on actual condition rather than a fixed 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 a sufficient circulation rate for accurate measurement and stable control of parameters.

The DRYCORE DC-5M online transformer monitoring system makes it possible to considerably decrease the number of failures, reduce diagnostic and laboratory analysis costs, avoid unplanned outages, and extend transformer service life by several tens of percent. Owing to remote access, advanced analytics, and the ability to operate continuously over long periods, this solution makes transformer operation predictable, controllable, and cost-effective. This type of online transformer monitoring system enables the transition from reactive, post-failure repair to preventive, condition-based asset management, which is fundamental to modern digital power engineering.