Research On Diagnosis Of Abnormal Fluctuations Of Thermal Power Unit Speed Control System

With the advancement of the UHV project,the structure of power system is more and more complex.At the same time,the thermal power unit has strong coupling.It has important practical significance to build a high precision abnormal fluctuations online early warning system for thermal power unit,and guarantee the safe and stable operation of power system.A highly accurate model is the basis of effective early warning system.Based on analyzing a variety of abnormal fluctuations,summarize the limitations of common model involving power network characteristics,and improve it.Then establish a complete steam turbine model,and apply to power system stability analysis.The simulation results show that the improved model conforms to the actual operation situation,but because of the less study on flow characteristic in the model,to a certain extent,the application of the model is restricted.In view of thermal power unit flow characteristic has an important influence on the model accuracy,starting from the mechanism analysis,combining with the historical data,a flow characteristic analysis method based on mass data is proposed.Based on the results of flow characteristic analysis,the high precision thermal power unit model for network simulation considering flow characteristics was carried out.In a detailed analysis of the core requirements,an early warning system for thermal power unit is developed.The model in this system involving three main functions: network unit modeling and correcting,early warning of abnormal fluctuation and real-time monitoring of primary frequency regulation margin.Finally the system was applied to the power unit in north China,to guarantee the safe and stable operation of power grid of this area.In the end of the paper,work is summarized.At the same time,improvements on the power unit analysis model and the online auxiliary decision system were prospected.