Load Scheduling Control for Main Steam Temperature of Power Generation Unit

For improving the load adaptability of main steam temperature control system, a load scheduling control structure is presented for the power generation unit. In this structure, the steam flow is selected as the scheduling parameter and four sets of local-controllers are embedded which are corresponding to four typical conditions. Each local-controller is designed and tuned by the cascade internal model control theory. The smooth switching among local-controllers is realized by the membership functions of fuzzy subsets. Because of the high order of outer-loop controllers, Taylor series expanded is adopted to reduce them to real PID. The presented control structure keeps the advantages of traditional cascade system: disturbance rejection, frequency increment, etc. Simulation tests show that the load scheduling control structure has good dynamic performance and can work well in a wide range of load.