Modelling, validation and control of steam turbine bypass system of thermal power plant

Abstract

Steam turbine bypass system, as an important auxiliary equipment of thermal power unit, plays a vital role in the process of start-up, shut-down, load rejection, and rapid load changes, and bypass temperature affects the normal operation directly. In order to study the bypass temperature dynamics, a dynamic model of high-pressure bypass system is established in this paper, and verified by fast cut back (FCB) field test data. The results show that the mathematical model has high degree of accuracy. Meanwhile, to solve the bypass over-temperature problem during FCB, the control technology based on static feed-forward compensation control (FCC) and linear active disturbance rejection control (LADRC) is proposed, and simulation results show that the control technology performance is better over the traditional controller, the optimal value of compensation coefficient of LADRC+FCC is 0.25 for the unit in this paper, which provides reference for the bypass control.