Research On Transient Stability Assessment Method Of Power System Based On MVEE And NHC

As an important part of power system security and stability analysis method,transient stability assessment plays an irreplaceable role in maintaining power grid security.In recent years,with the development of power grid technology in the direction of digitalization,informatization and intelligence,the transient stability assessment method has also transited from the traditional time-domain simulation method,energy function method to pattern recognition method.This paper focuses on the transient stability assessment method based on pattern recognition,and the main research contents are as follows:In the aspect of feature construction,according to the minimum volume enclosing ellipsoid(MVEE)optimizes the system trajectory information,determines the minimum volume closure ellipsoid containing all trajectory information in high-dimensional space,and constructs the input feature set using the physical attributes of the ellipsoid to complete the dimension reduction processing of the feature set,so as to enhance the feature identification ability of the classifier model and improve the accuracy of transient stability assessment.In the aspect of model training,the projection twin support vector machine(PTSVM)in the nonparallel hyperplane classifier(NHC)is introduced into the transient stability assessment as the classifier model,and the method of power system transient stability assessment based on MVEE and PTSVM is established.Compared with the traditional method based on support vector machine,this method pays more attention to the distribution of fault samples and has stronger generalization ability.The feasibility and superiority of this method are verified by the analysis of IEEE-39 node system and Nordic 32 system.In order to further improve the training speed of the model,based on the nonparallel hyperplane classifier nodel PTSVM,the regularization term is introduced into its objective function and the internal constraints of the evaluation model are improved,the least square projection twin support vector machine(LSPTSVM)is constructed,and the power system transient stability assessment method based on MVEE and LSPTSVM is established.The accuracy and effectiveness of the proposed method are verified by the analysis of IEEE-39 node system and IEEE-145 node system.