The complexity of power system phenomena challenges power system protection testing to obtain the required adequacy of the testing environment. Hardware-in-the-loop simulation in real-time substantially increases testing capabilities. However, there is still the question of the availability of commercial solutions. To address the challenges, a new hardware-in-the loop system has been designed and implemented utilizing the easily available Matlab/Simulink environment and Linux RT Preempt OS. The custom software part prepared for the presented system is based on the Matlab/Simulink s-function mechanism, Embedded Coder toolbox and Advantech biodaq library as the interface for the utilized I/O cards. The simulator’s real-time performance limits on Linux RT Preempt have been verified, and it was shown that its performance is sufficient to conduct successful tests of protection relays. Consequently, a simple power system protection relay testing example is provided, including a discussion of results. Finally, it has been proven that the presented system can be utilized as a simpler and more accessible hardware-in-the-loop testing alternative to commercial simulators.
Modern control and measurement systems are equipped with interfaces to operate in local area networks and are typically intended to perform complicated data processing and control algorithms. The authors propose a digital system for rapid prototyping of target application devices. The concept solution separates the processing and control section from the hardware interface and user interface section. Both sections constitute independent ARM-based controllers interconnected via a direct USB link. Popular libraries can be used and low-level procedures developed, which enhances the system’s economic viability. A test unit developed for the purpose of the study was built around a SoC ARM7 microsystem and an off-the-shelf palmtop device. It demonstrated a continuous data stream transfer capability up to 150 kB per second, which was sufficient to monitor the performance of an electricity line.