In this paper, a careful analysis of directional element behavior applied to a half-wavelength transmission line (HWL) is presented. Single line-to-ground (SLG) faults were applied, varying loading conditions and fault resistance. A commercial relay was used. Two directional elements were considered: 32QG and 32V. With the aim of obtaining directional element setting parameters, a Python program based on two-port
network theory was developed. The simulations were also performed in a hardware-in-the-loop (HIL) environment. It was observed that only the element 32V operated properly throughout the system during SLG fault conditions. It can be concluded that the conventional directional element algorithm can be applied to a system with a half-wavelength transmission line under the above-mentioned fault condition.
Juan D. Villón Berrocal, Maria C. Tavares, Presented at International Conference on Power Systems Transients (IPST2021) in Belo Horizonte, Brazil June 6-10, 2021.
KEYWORDS: Directional function, half-wavelength transmission, HIL, real-time simulation