SYNCHRONOUS generators are a primary source of reactive
power in electric power systems. Although there
are other important reactive power sources such as shunt
capacitors and Flexible AC Transmission System (FACTS)
controllers (e.g. Static Var Compensators or SVCs and Shunt
Static Synchronous Compensator or STATCOMs), to a great
extent, generators are responsible for maintaining adequate
voltage profiles across the systems [1]. Consequently, their
characteristics and their limitations are of major importance
for the analysis of power grids, particularly when the system
is operated near its limits. This is even more relevant under
the current competitive market environment,