In the drive toward a more resilient and decarbonised European energy grid, monitoring critical infrastructure is paramount. On April 18, 2026, a significant milestone was reached in the Slovenian pilot site of the OPENTUNITY project. Our partner Elektro Primorska (EP), in collaboration with ICCS, successfully installed specialized measurement equipment on three Medium Voltage/Low Voltage (MV/LV) transformers located in the Ajdovščina industrial park.

The Challenge: Real-Time Asset Management

Power transformers are essential components of the electricity distribution network, but they are often the most vulnerable to failure. Traditionally, asset management has been a long-term process, looking at equipment health over months or years. However, to ensure grid stability, there is a growing need for short-term asset management.

The tool developed by ICCS is designed to operate in a near real-time context. Its primary goal is to identify transformers that may be on the verge of failure within hours, allowing operators to intervene before a blackout occurs.

Innovation through Indirect Measurement

To predict these failures, the tool requires precise data on transformer load current,

ambient temperature, and top-oil temperature. A technical challenge arises because many older MV/LV transformers are not equipped with built-in top-oil temperature sensors.

To solve this, the team at Elektro Primorska developed an innovative, purpose-built measuring system. Instead of invasive procedures, the system uses Pt100 sensors with magnet holders placed directly on the transformer housing. This allows for the indirect measurement of top-oil temperature through a direct correlation with the housing temperature.

 

A Robust Technical Setup for Smart Monitoring

The installation at the Ajdovščina pilot site features a high-tech stack of industrial components designed for reliability and speed:

• Data Acquisition: The system utilizes Advantech components, including IoT gateways and RTD input modules, for local data storage and transmission.
• Environmental Sensing: Along with transformer housing temperature, the system includes an ambient probe to measure surrounding air temperature and relative humidity.
• High-Speed Connectivity: Data is transmitted via a secure MQTT protocol over a mobile LTE/4G network.
• Real-Time Visualization: Measurements are received at 5-second intervals and stored in an SQL database. This high frequency allows for a real-time dashboard where operators can monitor current and historical data instantly.

Why This Matters for the Future of Energy

This activity falls under the OPENGRID category of the OPENTUNITY project, which focuses on supporting Distribution System Operators (DSOs) in managing grid issues more effectively. By transforming standard transformers into “smart” assets, Elektro Primorska is demonstrating how existing infrastructure can be upgraded to support a more flexible and digitalised energy ecosystem.

As part of the broader Slovenian pilot, which also involves portions of the grids of Elektro Ljubljana, these advancements are crucial for utilizing the flexibility potential of domestic assets and electric vehicles while maintaining a stable and secure grid.

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Project Overview

• Location: Ajdovščina industrial park, Slovenia.
• Partners Involved: Elektro Primorska (EP) and ICCS.
• Key Innovation: Indirect top-oil temperature monitoring for predictive maintenance.