State-of-the-art prototype testing of PAC devices for the power industry

The company

Protecta Electronics Ltd., based in Budapest, Hungary, is a global leader in the design and manufacturing of digital protection relays and automation products for the power industry.

With more than 60 years of experience, Protecta provides advanced protection and control systems for high- and medium-voltage networks, serving power stations, utilities, and industrial applications worldwide.

Beyond protective relays, Protecta develops substation automation controllers, tap changer controllers, transformer inrush current minimizers, and arc suppression coil controllers, offering comprehensive solutions that ensure grid safety and reliability.

The challenges

Testing protection, automation, and control (PAC) systems is critical for ensuring power grid reliability. Traditional testing methods, based on offline waveform generation and replay, proved time-consuming, limited, and inflexible, especially when validating complex multi-device networks

Protecta faced several key challenges:

• Meeting stringent international validation standards that require thousands of automated test cases.
• Providing customized test demonstrations for clients’ specific power system configurations.
• Testing dynamic controller functions, such as transformer tap changers or Petersen coil controllers, that require real-time feedback.

To overcome these obstacles, Protecta sought a more comprehensive and adaptive testing platform capable of replicating realistic network behavior under fault and operating conditions.

The OPAL-RT solution

To meet these demands, Protecta integrated OPAL-RT’s OP4510 real-time simulator along with RT-LAB and eMEGAsim software into its R&D environment.

Using MATLAB®/Simulink® models, Protecta engineers created real-time simulations of power networks where analog and digital signals are exchanged directly with protection devices. This setup enables:

• Closed-loop testing where devices respond dynamically to simulated faults.
• Automated batch testing using Python scripts for thousands of test scenarios.
• Real-time coordination testing between multiple protection relays on the same network.

Specialized models simulate complex electrical phenomena such as:

• Evolving faults, CT saturation, and VT failures.
• Point-on-Wave (PoW) switching with a Transformer Inrush Current Minimizer (TRIM) function for smoother energization.
• Arc suppression (Petersen) coil control for compensated networks, accurately tuning residual current and voltage under single-phase-to-earth faults.

The real-time simulator allows engineers to adjust parameters on the fly, perform precise timing tests, and validate algorithms that previously required complex physical setups.

The results

The integration of OPAL-RT’s simulator has transformed Protecta’s R&D and testing processes, offering significant advancements in efficiency, flexibility, and accuracy.

Key outcomes include:

• Faster automated testing, reducing validation time while maintaining full compliance with international standards.
• Improved precision by replacing physical electrical models with real-time simulations.
• Expanded testing capabilities for multi-device coordination and complex protection schemes.
• Accelerated certification and homologation, facilitating Protecta’s entry into new global markets.

The future

Looking ahead, Protecta plans to expand its real-time test library to include busbar and line differential protection, as well as develop new models for IEC 61850-9-2 Process Bus testing. With OPAL-RT’s technology at the core of its R&D operations, Protecta continues to push the boundaries of power system protection innovation, ensuring safer, smarter, and more resilient energy infrastructure.

Read the full story