This paper presents a methodology to perform closed-loop Traveling Wave Relay Testing (TWRT) for transmission lines in power systems using RTDS real-time simulator. The Traveling-Wave Relays (TWRs) have a high sampling rate, e.g., around 1MHz, therefore, one requirement for TWRT is that the simulator operates at a small time-step, i.e., in the order of one microsecond. The TW-based protection elements operate based on current and voltage TW signals that are derived from the High-Frequency (HF) response induced by faults on the transmission line. This paper shows that employing inaccurate line models in a simulator can result in incorrect TW signals. Therefore, another requirement for TWRT is to use accurate line models. Fulfilling these requirements requires high computational power and introduces challenges to real-time simulators for the TWRT application. This paper presents two real-time simulator approaches for TWRT: (i) an FPGA-based and (ii) a multi-core CPU-based approach. The proposed approaches are employed to test commercially available TWRs and the results are reported.
Ramin Mirzahosseini, Yue Chen, Yi Zhang, Rick Kuffel, presented at 8th International Conference on Advanced Power System Automation and Protection, October 21-24, 2019
KEYWORDS: Hardware-In-the-Loop, Real-time, Traveling-wave, Relay testing