This paper deals
with the conflict between the input–output
response and the disturbance–output response, which cannot
be completely eliminated by traditional and advanced control strategies
without using the accurate process model. The inherently close association
of these two responses and the unavailability of the accurate process
model pose a great challenge to field test engineers of a coal-fired
power plant, that is, the design requirements of reference tracking
and disturbance rejection are compromised. In this paper, a novel
two-degree-of-freedom controller—feedforward compensated (FC)
desired dynamic equational (DDE) proportional–integral–derivative
(PID) (FC-DDE PID)—is proposed as a viable alternative. In
addition to achieving independent reference tracking performance and
disturbance rejection performance, its simple structure and tuning
procedure are specifically appealing to practitioners. Simulations,
experiments, and field tests demonstrate the advantages of the proposed
controller in both reference tracking and disturbance rejection, thus
making FC-DDE PID a convenient and effective controller for the control
of the coal-fired power plants, readily implementable on the distributed
control system (DCS).