  Hydro-Quebec (HQ) is a vertically integrated utility that produces,
transmits, and distributes most of the electricity in the province of Quebec.
The power grid it operates has a particular architecture created by large
hydroelectric dams located far north and the extensive 735kV transmission grid
that allows the generated power to reach the majority of the load located
thousands of kilometers away in the southern region of Quebec. The specificity
of the grid has led HQ to develop monitoring tools responsible for generating
so-called stability limits. Those stability limits take into account several
nonlinear phenomena such as angular stability, frequency stability, or voltage
stability. Since generation planning and operation tools rely mostly on mixed
integer linear programming formulation, HQ had to adapt its tools to integrate
stability limits into them. This paper presents the challenges it faced,
especially considering its reserve monitoring tool and unit commitment tool.
