Active Distribution Network Protection Scheme Based On Fault Current Sequence Component

With the rapid development of China’s economy,the national primary energy consumption is increasing day by day.China began to vigorously support clean energy represented by photovoltaic,which promoted the rapid development of Distributed generation(DG)power generation technology.Among a large number of distributed power distribution network access,changed the traditional distribution network of the network structure,make the distribution network failure trend of two-way flow,lead to the traditional three-step current protection may occur the phenomenon such as refusing action and error action,to have a negative impact to the safe operation of power grid,so the research of distributed power distribution network protection method is of great importance.Based on the above reasons,this paper proposes a distributed power supply fault current sequence component method of protection,the protection methods are mainly extracted at the ends of the line current sequence component of information as the failure criterion of conservation methods,the distribution network fault is divided into failure of asymmetry and symmetry gold attributes,among them,the asymmetry of the fault,Used on both ends of the line fault current negative sequence current phase cosine values as the criterion,for symmetric metallicity failure,with both ends of line fault current positive sequence current phase cosine values as the criterion,in order to ensure the fault correctly use the corresponding protection criterion,thus to distinguish between failure of asymmetry and symmetry gold properties,Therefore,the amplitude ratio of negative and positive sequence current at both ends of the line is used as the basis to distinguish,thus forming a complete protection method of distribution network with distributed power,and the effectiveness of the protection method is proved in the simulation results.Since the protection method proposed in this paper requires the positive and negative sequence current components at both ends of the line as the protection criterion,a method of detecting positive and negative sequence current components based on FBD is proposed on the basis of the protection method,in which the basic principle of FBD method and the theoretical basis of detecting positive and negative sequence current components are described.The method can detect the positive and negative sequence current components at both ends of the fault line in real time,so that the protection method proposed in this paper can use the detected positive and negative sequence current components to constitute a protection criterion,making it a complete distribution network protection method with distributed power supply.Finally,the proposed protection method is simulated and verified by a model built in MATLAB/Simulink simulation software.Figure[22]table[23]reference[80]...