The state space modeling approach was developed to cope with the demand
and performance due to the increase in system complexity, which may have
multiple inputs and multiple outputs (MIMO). This approach is based on timedomain
analysis and synthesis using state variables. This paper describes the
development of a state space representation of a furnace system of a combined
cycle power plant. Power plants will need to operate optimally so as to stay
competitive, as even a small improvement in energy efficiency would involve
substantial cost savings. Both the quantitative and qualitative analyses of the
state space representation of the furnace system are discussed. These include
the responses of systems excited by certain inputs and the structural properties
of the system. The analysis on the furnace system showed that the system is
bounded input and bounded output stable, controllable and observable. In
practice, the state space formulation is very important for numerical computation
and controller design, and can be extended for time-varying systems.