They are some Matpower limit loading cases considered in some references. They have been obtained as follows: the injected active and reactive power of load buses along the injected active power of generation buses have been increased in steps of 0.0001 pu until the standard NR diverged from a flat start. For instance, in the case1354pegase, the limit load is 1.3139 pu (1.3140 pu gives rise to divergence).