Elektrizace Železnic (EŽ), a leading Czech EPC (engineering, procurement and construction) company specializing in the development, design, and installation of overhead contact lines and power supply systems for railways and public transportation, has taken a significant step toward providing more reliable and efficient infrastructure.
In collaboration with ABB, EŽ has installed ABB’s AdvaSense™ sensors into a 25 kV AC single-phase switchgear in a railway substation in the Czech Republic. This installation marked the first-ever application of AdvaSense sensors in a railway environment in the country.
Designed for medium-voltage power networks, these compact and highly reliable sensors offer an alternative approach to conventional instrument transformers. They provide current and voltage measurements based on well-established principles that enable enhanced safety, while offering significant size reduction. The sensors require minimal maintenance and are ideal for space-constrained and demanding environments.
Their wide dynamic range ensures accurate measurement across a broad spectrum of input currents, and their full potential is realized when paired with intelligent electronic devices (IEDs), such as protection relays, to enhance monitoring, protection, and control capabilities. Sensors provide accurate data on voltage and current, while IEDs process this information to enable advanced diagnostics, predictive maintenance, and faster response to faults.
To address these needs, EŽ selected KEVA 48 B20 sensors for voltage measurement and KECA 80 C85/D85 sensors for current measurement from the AdvaSense product family. The KEVA 48 B20 sensor was developed as a variant to suit the specific requirements of this application, reflecting the close collaboration between EŽ and ABB in tailoring the solution to the project’s needs.
EŽ chose ABB not only for the advanced technology, but also for the comprehensive support throughout the project. ABB provided full technical support to adapt the sensors for the railway environment, ensuring a smooth integration process. The collaboration also included the implementation of ABB’s Relion® protection relays - REX615, REX640, and REF615 – in the substation to further enhance protection and control of the power system.
"By replacing conventional instrument transformers with the AdvaSense sensors, we’ve improved the safety and reliability of the switchgear and the solution. The risk of saturation due to multi-spectral harmonic waves in the conventional current or voltage transformers has been minimized. At the same time, we’ve managed to reduce the overall footprint of the installation, thanks to the sensors’ significant size reduction. The simplified design also enabled faster commissioning,” said Ales Kobulej, Manager of system development and technology at EŽ.
This project represents the first application of ABB’s AdvaSense sensors in a railway setting in the country, setting a new benchmark for future smart, safe, and high-performing solutions.
The switchgear at the substation. AdvaSense sensors are suitable for all types of medium-voltage switchgear - for both new installations and retrofits.The sensors are fully compatible with ABB’s Relion protection relays as well as other manufacturer’s relays that support low-power sensor technology. 
The KEVA 48 B20 AdvaSense voltage sensor is installed in the switchgear 
The KECA 80 D85 AdvaSense current sensor is also installed in the switchgear in the railway substation. 
Sensors, also known as low-power instrument transformers, offer current and voltage measurements for medium-voltage protection and measuring systems.
