Internal Model Control For Main Steam Temperature Control System In Thermal Power Plant

In thermal power plant，the dynamic behavior of the main steam temperature showscharacteristics of great delay，big inertia，time variance and non-linearity, which makes theconventional PID cascade control cannot achieve satisfying control performance when theconditions change. It analyses the importance and difficulty of the main steam temperaturecontrol, gives the mission of the main steam temperature’s control, and studies the characteristicsof the main steam temperature in thermal power plants. It determines control means of the mainsteam temperature and gives the design principles of the main steam temperature control systemwithin the mold followed by analyzing the impact of the main steam temperature of three majordisturbances. Considering characteristics of the main-steam temperature an internal modelcontrol-PID cascade control system is presented which is combined with the merits of IMC andthe cascade control in the paper.Proportional control is used in the inner loop and IMC is used inthe outer loop in order to eliminate the interference quickly and shorter the controlling process’sduration. It overcomes the disturbance and compensates time-delay of object. The software ofsimulink is used for simulation and the results show that the internal model control-PID cascadecontrol system of integrated performance is better than the conventional cascade PID controlsystem, and the designed system has good position tracking property, adaptability to overcomedisturbances and robustness.