Study On Impact Of DG On Power System Stability

Distributed Generation (DG) has been widely used in the electric power system as a clean, efficient and flexible new energy. Besides the economic benefits, DG also brings the inevitable impact to power system. This paper focuses on the study of impact to stability after DG merged to power system network.First mainly part is the introduction of the common types of Distributed Generation, the analysis of distributed power generation's merging interface to power system network. According to the merging method to power system network, DG can be divided into three types:synchronous generator interface DG, asynchronous generator interface DG, power electronic converter interface DG. This paper gives a detailed analysis on the DG steady model in power flow calculation based on these three type DGs and studies the DG's process method in power flow calculation. Separately written Newton-Raphson and Sensitivity Matrix power flow algorithm program, Based on the power flow algorithm program, analyses the influence to power system after various types of DG merged into power system grid. It's found that synchronous generator interface DG has a negative impact on power system.Secondly, study eigenvalues analysis method and monte-carlo small signal stability analysis method, compare the two kinds of analysis method, for the load and operation mode are determined in this paper, choose the eigenvalues analysis method to analysis.Finally, create three type DGs'mathematical model, write calculation programs for small signal stability analysis. Based on these through the simulation, study on DG's merging into different position of power system with different type, different capacities, analysis the small signal stability, it's found that synchronous generator interface DG has a negative impact on power system angle stability, asynchronous generator interface DG and power electronic converter interface DG have improvements to power system angle stability to some degree.