The Research Of Grid Disturbance Identification Method Based On WAMS

The smart grid technologies are rapidly developing,the size of the grid are also increasingly increasing,the grid structure is becoming more complicated.The large disturbance interference in power grid is more and more to occur,and large disturbance effect on the safety of power grid is increasingly prominent,the damage to the power grid security is become bigger,when the disturb such as short circuit occur in the power grid,If don't timely judge the type of the disturbance and timely deal with it,the disturbance occurred around the large area will be affected,severe cases can appear even large area power outage.So,in order to quickly understand the occurrence situation of large grid disturbance.and take the corresponding means and measures to eliminate or restrain the disturbance effects on the grid.Research the method is suitable for on-line identification of large power grid disturbance has great significance for the safe and reliable operation of power grid.Grid disturbance identification is using the variation characteristics of grid electric parameters before and after large disturbances to identify disturbance type.Generally includes disturbance feature extraction and disturbance classification two phases.So,this paper Select the expert system based on the theory of multi-source information fusion as the feature extraction method and' the large disturbance classifier based on the theory of decision tree as the large grid disturbance recognition method.This article first on the theory to analyze the disturbance mechanism of several large disturbance of power grid in common,get the qualitative characteristics of all kinds of disturbance.At the same time,using PSASP software to make disturbance simulation on three machines nine nodes system,and analyze the simulation data,to determine the positive sequence voltage amplitude and phase angle,zero sequence voltage and negative sequence voltage as the disturbance perturbation of identifying grid disturbance.Based on the theory of multi-source information fusion,adopting a expert system disturbance eigenvalue extraction method,By expert system for the several index can characterize large disturbance of grid make weights hierarchical processing,and to determine the relationship of between the individual weights of each index,finally can quickly extract the needed disturbance criterion from the large amount of data measured by PMU and SC AD A,combined with the feature of disturbance trends,to generate a decision tree disturbance classifier,according to the classification function of the decision tree to identification the large disturbance.Finally,put forward the basic flow of the disturbance identification method and disturbance identification procedures,to complete the automatic identification of disturbance.In this paper,using the MATLAB software,take the three machines nine nodes system disturbance example as a perturbation initial data,demonstrate the effectiveness of the proposed identification method,finally apply it in the areas of a certain oil field power grid.