Method for controlling main steam temperature in power plant based on simplified second-order auto disturbance rejection controller

Abstract

The invention discloses a method for controlling a main steam temperature in a power plant based on a second-order simplified auto disturbance rejection controller. In the method, a cascade control mode is used for forming a cascade steam temperature mediation and control system; in an inner ring, proportion integration differentiation (PID) adjustment is used for eliminating the deviation of an advance timing steam temperature to achieve a coarse tuning effect on an overheating steam temperature; in an outer ring, the simplified second-order auto disturbance rejection controller is used for controlling the outlet temperature of an overheater, so that the defects of large inertia and large delay of a temperature object in an inertia area are fully overcome; and by a disturbance compensation effect of the simplified second-order auto disturbance rejection controller, the disturbance of factors such as loads, flue gas and the like is eliminated, so that the stability of the main steam temperature is ensured. In the method, an algorithm is simple, a parameter is easy to adjust, and a higher response speed, higher steady state accuracy, higher disturbance resistance and higher robustness can be well acquired without dependence on a mathematical model with an accurate main steam temperature in the power plant.

Description

technical field [0001] The invention relates to a temperature control method of a power plant, in particular to a temperature control method of main steam in a power plant based on a simplified second-order active disturbance rejection controller. Background technique [0002] At present, maintaining the stability of superheated steam temperature during boiler operation is of great significance for reducing equipment loss and ensuring the safe operation of the entire heating network. However, the complex characteristics of the main steam temperature control object, such as time-varying, uncertain and nonlinear, bring certain difficulties to conventional control. The traditional PID cascade control scheme is mostly used in the main steam temperature control system of traditional thermal power plants; however, it is difficult to use conventional PID control due to the uncertainty of model parameters and problems such as environmental changes and component aging during the oper...

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Problems solved by technology

[0003] In order to overcome the shortcomings of the existing control strategy in the main steam temperature control process of the power plant, such as poor adaptability, weak anti-interference ability, and easy to be affected by system parameter changes, this patent proposes a simplified second-order active disturbance rejection control method, which can Overcome the large inertia and large delay defects of the controlled object, and provide disturbance compensation to overcome the load, flue gas flow and other disturbances in the environment of the controlled object

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