Abstract: The steam temperature control method is put forword,and an improved PID control algorithm is designed in the cooling water control circuit, and a modified instruction with self-learning function is introduced to adjust the parameters. In the coordinated control loop, a coordinated control algorithm based on running state analysis and humanoid modification is designed. In practical application, the steam temperature of a 630 MW supercritical unit is well controlled in wet stable operation and variable load operation, dry stable operation and variable load operation under 28.7%~100% rated load interval, the control quality of some working conditions has improved more than 60% compared with the industry standard. When a 1 000 MW ultra-supercritical unit is running in 30%~100% rated load range, the steady state control quality of steam temperature is improved 30%~60% compared with the industry standard.

Key words: thermal power units, wide load peak shaving, steam temperature control, self-learning, supercritical