Research On Comprehensive Optimization Strategy Of Large Steam Turbine Electric Generator AGC Performance

At present,due to the large-scale consumption demand of new energy power generation with strong random uncertainties such as wind power,the grid has set higher requirements for the AGC performance of thermal power units;how to improve the comprehensive regulation capability of thermal power units' AGC has long been A hot research topic.Existing researches mainly focus on boilers,steam turbines,and related auxiliary engines.By analyzing their direct or indirect effects on AGC,they propose targeted optimization or transformation methods.However,there are many types of actual thermal power units,different equipment conditions,and complex and variable operating conditions.Therefore,it is difficult to achieve a significant improvement in AGC performance through a single method.Therefore,this article takes six large-scale steam turbine generator sets of the Dalat Power Plant as the research object,and develops a comprehensive optimization method research to improve the AGC regulation performance of the unit.The corresponding research is carried out from three aspects:boiler main steam temperature,steam turbine load signal and auxiliary equipment The control strategy is optimized and the corresponding simulation verification analysis is performed.First,the research and study of the superheated steam temperature system was carried out.Because the superheated steam system is a key component of the unit-boiler coordination,the quality of the main steam parameters directly affects the overall unit coordinated control effect,and its own large inertia The large delay characteristic affects the performance of the unit participating in the AGC adjustment to a certain extent.Therefore,in the study,by fully analyzing the characteristics of the system,a control strategy combining state-prediction and multiple models was proposed to improve the quality of the main steam temperature adjustment and reduce the influence of the main steam temperature fluctuations and lags on the AGC adjustment performance of the unit;Then,since the steam turbine system is an important component of the coordinated control system,it has the same characteristics of lag and delay as the superheated steam system,so based on the above research,a hierarchical feedforward optimization strategy is proposed for the steam turbine control side.The processing of the load signal enables the unit to make reasonable use of the unit's energy storage during the adjustment process in order to increase the load response rate,thereby improving the AGC adjustment performance of the unit;In addition,in the study of this subject,for the main auxiliary engine system,first of all,based on the optimization and optimization of the main steam turbine,a method for optimizing the linear control of the rotational speed of the small steam turbine of the feed water pump of the thermal power unit is proposed.The non-linear control curve of the inlet steam flow rate realizes the rapid adjustment of the feed pump speed and the continuous and uniform supply of boiler feed water,which effectively improves the load response capability of the unit.In addition,the existing slag-removing machine has been retrofitted and upgraded.Although the above auxiliary machine system does not directly affect the adjustment performance of the unit AGC,the efficient and rapid optimization and upgrade of the system has played a role in improving the overall adjustment performance of the unit's AGC.Finally,according to the easy-to-implement steam turbine feedforward control strategy,the optimization of the small steam turbine flow characteristic curve,and the method of measuring the water level of the slag-removing machine,actual application was carried out on 6×330MW heating units and in the Dalat Power Plant And achieved good application results.