Direct Lightning Performance Assessment of 6.6  <scp>kV</scp> Distribution Lines Taking Account of Regional Characteristics

Abstract Lightning outages caused by indirect lightning strikes are less frequent in well‐protected medium‐voltage distribution lines, such as Japanese 6.6 kV medium‐voltage distribution lines. This paper proposes a method for assessing the direct lightning performance of 6.6 kV medium‐voltage distribution lines while taking regional characteristics into account. The proposed method consists of two main components: (i) direct lightning surge analysis using an electromagnetic transients analysis tool developed based on the latest findings, and (ii) applying a correction factor to the surge analysis results to account for regional characteristics. This approach can accurately estimate regional trends in lightning outage rates and contribute to the study of rational lightning protection design. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.