Research Of Coordinated Control Strategy For Ultra Supercritical Unit Of 1000MW

With the development of materials technology and the improvement of the requirements of energy saving and environmental protection, thermal power generating units who makes use of supercritical technology has the advantages of high efficiency, energy saving, clean combustion. So it has been widely used in our country power construction. Supercritical and ultra supercritical units with direct current boiler has greatly changed the process and object properties, so the study on the automatic control should adopt a new method.The coordinated control system takes the boiler and turbine as a whole, and it makes them action coordinated upon the characteristics of the turbine and boiler, so it can meet the requirements of the power grid load and make the operation parameters stable. As the large capacity and ultra supercritical units have a large share in power grid, the study of coordinated control is the key to ensure the stability of grid. Compared with the subcritical units, the ultra supercritical unit has great changes in thermodynamic system. The main difficulties are the boiler feed water and the control of the main steam temperature and main steam pressure. Therefore, the study of the ultra supercritical unit coordinated control strategy is helpful to improve the level of control, which plays a guiding role in safe and efficient operation of unit.This article takes the coordinated control of Xuzhou power plant, 1000 MW ultra supercritical unit as the research object. According to characteristics of the unit and the problems in the practical running, the article makes the analysis of the logic in turbine boiler control system, main steam pressure system, the feed water system, and(RUNBACK) system. Combined with the optimization of coordinated control system of Guodian Zhishen company, the load acceleration signal, calorific value correction, and optimization of boiler control’s integral action are the most important characteristic. The operation curve after optimization proved that the control effect reached the requirements.