Once-through boiler unit set coordinated control system and design method thereof

Abstract

The invention belongs to the field of automatic control of power plants, and particularly relates to a once-through boiler unit set coordinated control system and a design method thereof. The once-through boiler unit set coordinated control system comprises a coal pulverizing system, a once-through boiler, a steam turbine, a power sensor, a pressure sensor, an enthalpy value sensor, three PI controllers and a decoupling compensator, wherein the decoupling compensator is composed of eight PID controllers. According to the design method, an ultra-supercritical unit simplification nonlinearity dynamic model which is simple in structure and has an analytical form is established through mechanism analyzing. Linearization is carried out on the unit set model based on the small deviation method, and after inversion is carried out on the core model, the decoupling compensator is obtained, and a three-input and three-output coordinated control system of a once-through boiler unit set is established. Decoupling between the boiler side and the steam turbine side and between the fuel side and the water feeding side can be achieved, and the problem that an existing control method depends on the fuel and water ratio coefficient is solved.

Description

technical field [0001] The invention belongs to the field of automatic control of power plants, in particular to a coordinative control system and a design method of a once-through boiler unit unit. Background technique [0002] With the rapid development of my country's economy and the advancement of the construction of a resource-saving society, the super (super) critical DC furnace unit with the characteristics of high efficiency, low emission and strong load adaptability has become the main unit of thermal power generation in my country. Due to its large capacity and other characteristics, the safe and stable operation of these units is the basis and key to the safe and stable operation of large power grids. [0003] The object structure model of the coordinated control system of a once-through boiler unit unit is usually simplified as a three-input and three-output system. For pressure and turbine power, there are cross-correlation and strong coupling phenomena between...

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Problems solved by technology

However, the two schemes have their own advantages and disadvantages. Because the water supply is much faster than the fuel adjustment, the water and coal control scheme is beneficial to the control of the main steam temperature, but the main steam pressure will fluctuate greatly, while the coal and water control scheme is beneficial. The control

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