A Predictive Control Method for Supercritical Units Based on Decoupling and Disturbance Observation

Abstract

The invention discloses a predictive control method for a supercritical unit based on decoupling and disturbance observation. The method takes the supercritical thermal power unit as the controlled object, takes fuel quantity, water supply quantity, steam turbine valve opening as input, and main steam pressure , midpoint temperature, and unit load are the outputs. First, the controlled object is approximately decoupled through the feedforward compensator, and then the disturbance is observed through the disturbance observer set in each channel to realize the multivariable control of the controlled object. Predictive control solves the problem of poor control effect caused by disturbance in the coordinated control system of supercritical units. It can effectively suppress the influence of external unmeasurable disturbances, and at the same time suppress the internal disturbances caused by the coupling between input variables, thereby improving the performance of supercritical units. The control performance of the unit coordination control system.

Description

technical field [0001] The invention belongs to the field of thermal automatic control of supercritical thermal power units, in particular to a supercritical unit predictive control method based on decoupling and disturbance observation. Background technique [0002] During the operation of supercritical thermal power units, the coordinated control system is affected by internal disturbances caused by model mismatch and variable coupling, as well as various external disturbances. The existence of these disturbances significantly reduces the control effect of the controller. [0003] When many advanced control algorithms deal with strong disturbances, because there is no targeted disturbance rejection design in the controller, the dynamic characteristics of the system are still insufficient, which affects the control performance. In addition to the measurable disturbances, there are also a large number of disturbances that cannot be measured online in the coordinated control ...

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Problems solved by technology

[0005] Purpose of the invention: In order to solve the problem of poor control effect caused by interference in the coordinated control system of supercritical units in the prior art, the present invention provides a predictive control method for supercritical units based on decoupling and disturbance observation, which can effectively suppress The impact of various unmeasurable disturbances in the field further improves the control performance of the coordinated control system. This method only designs a disturbance observer for the main diagonal channel, which reduces the complexity of the control system structure and effectively suppresses the strong coupling of internal factors in the system. internal disturbance

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