  In this paper, a novel distributed controller for multimachine power systems
is proposed to guarantee grid frequency restoration and accurate real and
reactive power sharing among the generator units, while maintaining the
generator inputs (mechanical torque and field excitation voltage) within given
bounds. The boundedness of the controller outputs (generator inputs) is
rigorously proven using vector field theory. It is additionally shown that even
if one generator input reaches its upper/lower limit, the remaining units can
still accomplish the desired control tasks without modifying the controller
structure or dynamics; hence introducing enhanced system resilience using the
proposed approach. This has been accomplished in a unified control structure
while using neighbour-to-neighbour communication, thus maintaining the
distributed nature of the controller. An example of a 10-bus, 4-machine power
system is simulated to verify the proposed controller performance under sudden
changes of the load demand.
