Method for simulating and modeling controlled object in distributed control system of thermal power generating unit

Abstract

The invention relates to a method for simulating and modeling a controlled object in a distributed control system (DCS) of a thermal power generating unit. The method for simulating and modeling a main analog controlled object comprises the steps of: a, calculating water feed pressure, feed water flow and separator pressure parameters in a simplification manner according to the rotation speed of a water feed pump; b, simplifying a water level of a steam drum / separator into the integral of a flow difference between an inlet working medium and an outlet working medium; c, determining steam flow by calculating the dryness of the working media; d, calculating temperature based on the pressure and enthalpy by using an integrating function of a PID (Proportion Integration Differentiation) module, and then simulating to calculate main steam temperature; e, simulating to calculate smoke quantity and the suction capacity of a draught fan, and further simplifying and simulating the negative pressure of a discharge hearth; f, simulating to calculate the combustion capacity of a boiler according to the rotation speed of a coal feeder; and g, simulating to calculate a unit load according to the combustion capacity or the main steam flow. According to the invention, by means of a simulation method for establishing a controlled object simplified model inside a DCS system by adopting a DCS configuration tool, the control over a closed loop is realized.

Description

technical field [0001] The present invention relates to the field of automatic control of thermal power units, in particular to a simulation modeling method for the control object of the distributed control system (DCS) of thermal power units, which is mainly used in the control function software configuration process of the distributed control system (DCS) of thermal power units In the simulation model, the control function is simulated and debugged by establishing a simulation model, that is, the function test and parameter initial setting are realized. Background technique [0002] The distributed control system (DCS) is the "central nervous system" of the generating set, which can realize functions such as sequence control, protection tripping, automatic adjustment, and parameter monitoring. Whether these control functions are normally realized is closely related to whether the unit can operate safely and reliably, so it is very necessary to carry out functional tests o...

AI Technical Summary

Problems solved by technology

[0004] At present, the simulation models used in various DCS simulation methods use mechanism models and complex mathematical operations, and are built outside the DCS system by using tool software. It is difficult to create conditions for data interaction with these models during configuration testing.

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