Automatic gain control (AGC) optimizing control method of supercritical unit under coal quality changes

Abstract

The invention discloses an automatic gain control (AGC) optimizing control method of a supercritical unit under coal quality changes, which comprises (1) correcting differential feed-forward of main vapor pressure deviation according to a coal quality correction coefficient British thermal unit (BTU), (2) correcting proportion feed-forward of unit load instructions according to the coal quality correction coefficient BTU, and (3) correcting proportion coefficient K of boiler master control according to the coal quality correction coefficient BTU, overlying the corrected differential feed-forward of the main vapor pressure deviation in the step (1) and the corrected proportion feed-forward of the unit load instructions in the step (2) to serve as new master control feed-forward of the unit boiler, enabling the corrected proportion coefficient K of the boiler master control in the step (3) to serve as an input quantity in a follow-up proportion integration differentiation (PID) step, and achieving output control of the unit boiler master control. The AGC optimizing control method of the supercritical unit under the coal quality changes has the advantages that by optimizing a logic structure of a unit boiler master controller, measures of sectional parameter varying are adopted specific to different coal quality, stability of main vapor pressure of the unit is effectively ensured, and control quality and key performance indexes of the AGC of the supercritical unit are improved.

Description

technical field [0001] The invention relates to an AGC optimization control method for a supercritical unit, in particular to an AGC optimization control method for a supercritical unit under coal quality changes. Background technique [0002] With the development of material technology and the continuous improvement of energy-saving requirements, supercritical and ultra-supercritical units have been more and more widely used in domestic power supply construction. The capacity of the power grid is getting bigger and bigger, and the quality of electric energy is also getting higher and higher. For the safe and stable operation of the power grid, all large-scale thermal power units are required to use the AGC function, and the load range of the AGC control unit is required to be large (generally 50%-- 100% rated load), and requires the unit to have a fast, accurate and stable response to load changes. [0003] 1. AGC assessment standards and conventional control schemes for p...

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Problems solved by technology

[0012] This control scheme works well when the working condition of the unit is stable and the coal quality is stable, and the control effect of pressure and temperature is better, and the AGC assessment can meet the requirements of the middle adjustment, but when the coal quality changes, especially when the change is large, the main parameters such as pressure fluctuate Larger, affecting the response speed and control accuracy of the load, resulting in AGC assessment quality not up to standard

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