Dear Jiashen:
The model used in Matpower is the standard pi one-line equivalent of a
three phase transmission line, with quantities in per-unit. This is
constructed from a base voltage equal to sqrt(3) times the phase voltage
and a base power equal to three times the per-phase power. With this
choice of base quantities, the base impedance is equal to the per-phase
impedance. This is covered in most power systems analysis textbooks.
carlos.
Jiashen Teh wrote:
Dear Dr Ray,
Before asking my question, allow me to put us on the same level of
understanding.
If I am not mistaken, each transmission line in reality is actually
consists of 3 conductors connected in parallel.
Hence, these are my 2 questions based on the above assumption:
The resistance values in Matpower are
(a) the total resistance of 3 conductors connected in parallel?
or
(b) the resistance for only one of the three conductors?
The line ratings in Matpower are
(a) the total rating for 3 conductors connected in parallel?
or
(b) the rating for only one of the three conductors?
Yours sincerely,
Jiashen Teh
PhD Student
Electrical Energy & Power Systems Group, School of Electrical &
Electronic Engineering
Ferranti Building (B18), The University of Manchester, M13 9PL, United
Kingdom
Tel: +44 (0) 161 306 2263; Mobile: +44 (0) 792 322 4864
