Limiting surge arrester failure under direct lightning strokes for attaining service continuity of distribution networks

This study introduces an arrangement of surge arrester, Rogowski coil, and triac to attain service continuity of distribution networks. This new arrangement is proposed to limit the arrester failure due to lightning flashes striking distribution feeders. The arrester failure is probably happened due to the increase of absorbed energy over the withstand capability. As the lightning flash has multiple discharges, an equivalent single wave model is computed to evaluate the arrester discharge energy. The arrester discharge current is monitored using a single Rogowski coil. Then, the arrester's dynamic characteristic (current–voltage) is utilised to estimate the discharge energy using only the arrester current. The arrester and associated Rogowski coil are distributed in an 11 kV distribution network. Due to travelling-waves reflections of the direct lightning striking the distribution feeder, the discharge energy of the installed arresters in the network is different than the computed energy using the lightning flash current as an impulse current source directly applied on the arrester device. Finally, the parallel triac with the arrester is suggested and triggered for limiting the arrester's failure. The detailed model of this proposed arrangement is evaluated via an electromagnetic simulation software. The failure assessment is statistically evaluated using the MATLAB software.