| Reheater is one of important heat-exchanger in high-capacity power plant boiler, and the performance of reheater temperature control is vital to economic operation and safe production of electricity industry. Especially when high capacity units always participate in electricity network load adjustment, reheater temperature control system is required to be an improved performance level.This thesis, based on the existing reheater temperature control examples of Hua Neng Power Plant(HNPP) enlarged 2×350MW reheating units, researched and analyzed, in details, the dynamic characteristics of the reheater temperature adjustment system of our country present main power-generating units like 200MW-300MW, and accordingly discussed the inevitable characteristics including nonlinear, time-lag, multi-variable coupling. And also, this thesis first proposed a H∞ state space variable robust control strategy for 300MW units reheater temperature control, and showed a relevant SAMA configuration via Spec200 design block and its realization. Now, the main contents of this thesis can be summarized as follows:(1) On the base of previous mathematical model for single phase zone heating surface, this thesis, through Laplace Transformation of difference equations at given parameter points, individually deduced three differential transcendental transfer functions, which can describe the responses of outlet temperature or enthalpy value of controlled objects to inlet variables like flow flux, temperature and enthalpy;(2) Based on analyzing the step responses under different relevant disturbance single-phase zone superheating surface area, the thesis showed transfer functions respectively for superheater and reheater temperature adjustment system;(3) Through third-order Taylor expansion and practical engineering simplification, the thesis derived three typical expressions for the reheater temperature adjustment system when it is disturbed by the three variables such as flow flux, temperature and enthalpy.
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