Research On Primary Frequency Control System And Power Grid Coupling Analysis

With the development of power grid,power system operation is facing more complex and changeable security problems.Large-scale blackouts caused by the frequency instability of the power grid occur frequently.These accidents warn that it's necessary to conduct a thorough study of the primary frequency control characteristics of generating units.Analysis of the coordinating generators with electrical network and grasp the relationship between the power network frequency characteristics and the unit can provide a more effective guarantee for the safe and stable of power grid.Based on the analysis of power system primary frequency control and existing problems,this paper establishes a multi-machine rigid model for frequency study and and the range of parameters of primary frequency control system under single,double and multi-machine grid is given by the Louth criterion.In this paper,the union simulation model of power plants is built on Matlab/Simulink platform.The union model is introduced to study the influence on frequency control of the power grid caused by the operation mode and parameter setting of the primary frequency control system in thermal power units.The simulation results verify the stable operation conditions proposed in chapter 3 and show that the unreasonable parameter setting of the primary frequency may enlarge the frequency fluctuation of the system or directly become the disturbance source of the low frequency oscillation of the power grid.