Dear all,
I noticed some lines with very high (1.0 and above) R/X values in certain test
cases For example,
1. in case300.m, branches
* (9021, 9023) R/X ratio = 1.1617
* (9003, 9044) R/X ratio = 1.1615
* (9044, 9004) R/X ratio = 1.3241
2. in case2869pegase.m, branches
* (3095, 2951) R/X ratio = 1.8244
* (8209, 1998) R/X ratio = 1.4405
* (1216, 5233) R/X ratio = 1.1316
* (4318, 1338) R/X ratio = 1.0228
* (6047, 5271) R/X ratio = 1.0783
* (6047, 5271) R/X ratio = 1.5017
I'm wondering why this is the case and whether they are physically realistic.
I'm working on an iterative power flow algorithm and have found that high R/X
ratio (1.0 and above) in the branches causes my iterations to diverge, so I
want to decide between going back and revise the theory, or to simply put a
footnote, e.g., "R/X ratio should not be too high." Numerically, capping these
lines at R/X = 0.999 still allows for convergence, but more slowly as the
maximum gets closer to 0.999.
Best regards,
Jeffrey Chen
