Non-linear compensation control method of steam inlet regulating valve of steam-driven water feeding pump

Abstract

The invention relates to a non-linear compensation control method of a steam inlet regulating valve of a steam-driven water feeding pump. The method acquires opening command signals of regulating valves for controlling the rotating speed of a steam pump in the following manner: the quotient obtained by dividing the difference between a steam pump rotation speed command signal and a rotation speedfeedback signal by the total gain coefficient signal after inertia filtering is sequentially processed by a PID controller and a manual / automatic operation station module to obtain a comprehensive valve position signal, the difference between the comprehensive valve position signal and an output signal of a first analog quantity constant module is processed by a first high-low amplitude limiting module to obtain an HP opening degree command signal, and the comprehensive valve position signal is processed by a second high-low amplitude limiting module to obtain an LP opening degree command signal. According to the method, non-linear gain calculation logic is designed for three types of non-linearities respectively, and finally the three types of non-linearities are combined into a total gain coefficient in a product mode to compensate the gain of a steam pump rotating speed control system, so that centralized compensation of the three types of non-linearities is realized. The method caneffectively improve the control quality of the steam-driven water feeding pump, thereby avoiding caused steam pump rotating speed out-of-control faults.

Description

technical field [0001] The invention relates to a method for controlling a steam inlet regulating valve of a steam-driven feedwater pump of a thermal power unit, and belongs to the technical field of control. Background technique [0002] Due to the advantages of low comprehensive energy consumption and good regulation characteristics, most thermal power units use steam-driven feed water pumps (referred to as steam pumps) as the boiler feed water power source under normal working conditions. The main body of the steam pump is composed of a small steam turbine driving a feed water pump. The steam flow into the small steam turbine is adjusted through a set of regulating valves to control the speed of the small steam turbine, and then control the feed water flow. [0003] The steam source of the steam pump comes from the four-stage extraction steam of the steam turbine, the second-stage extraction steam, and the auxiliary steam header steam. The thermal system structure is as f...

AI Technical Summary

Problems solved by technology

Due to the existing steam pump speed control logic (see figure 2 ) There is no ideal compensation method, and it is difficult to set the compensation parameters of the three nonlinear superpositions, which may easily lead to difficulty in controlling the speed of the steam pump at certain operating points, which in turn leads to severe fluctuations in the feedwater flow

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