Transient stabilty constrained interior pt. optimal power flow, J. Quanyuan
Two problem sets from Dr. Jiang Quanyuan from Zhejiang University,
Hangzhou, China, March, 2008, used in an electrical power system.
Each matrix A is solved sequentially with two right-hand-sides, b1 and
b2, one at a time.  In the UF collection, the sequence of all first
and second right-hand-sides is in Problem.aux.b2 and Problem.aux.b1.
These matrices are symmetric indefinite (x=A\b uses MA57).
Note that the last matrices in the sequence are ill-conditioned.

Transient Stability Constrained Interior Point Optimal Power Flow Program
      Version 1.0 -- Developed by Dr. Jiang Quanyuan, March 2008

case9.m - TSOPF converges after 12 iterations
 object    = 3.945939E+03
 max_equ   = 3.287326E-11
 low_inequ = None
 up_inequ  = None

case39.m - TSOPF converges after 13 iterations
 object    = 2.696268E+04
 max_equ   = 5.684342E-14
 low_inequ = -1.110223E-16
 up_inequ  = None