Figure 7

Phase tensor ellipse and β for sensitivity test for two representative periods. (a) 40 s and (b) 400 s. The dotted squares show the horizontal location of the area where the C2 conductor is replaced with 100 Ωm. The calculated β values of the sites west of the C2 conductor are significantly underestimated. We do not see significant differences with and without the C2 as seen in phase tensor ellipses; however, without the C2 conductor, the observed large β value to the west of the C2 is not explained.