This paper presents a new distance protection element implementation that is based on the classic analogue principle of coincidence timing between the distance element operating and polarizing signals. The paper explains the basics of coincidence timing and the many advantages of this approach. It explains why early digital relays could not afford this implementation method and why they settled on using heavily-filtered phasors. The paper focuses on describing a modern digital implementation of distance protection elements based on coincidence timing that combine advantages of the core analogue principle with several extensions and improvements taking advantage of the digital relay technology. The new algorithm has been implemented in a hardware platform and consistently operates with speed on the order of half a cycle. The paper illustrates the new approach using a field case and shows laboratory test results from hardware-in-the-loop tests.
B. Kastenny, M. Mynam, T. Joshi, A. Kathe, C. Daniels, Presented at the 15th International Conference on Developments in Power System Protection, DPSP, Liverpool, 9 - 12 March, 2020
KEYWORDS: Power system protection, distance protection, coincidence timing