Fault Location Method Of Distribution Network With IIDGs Based On Regional Models

The Inverter Interfaced Distributed Generation(IIDG)is widely used in distribution network because of its flexible control mode.By the time improve the reliability of power supply and reduce the transmission loss,the distribution network also appears reverse power flow phenomenon.The characteristics of plug and play make the network structure change frequently,and the flexibility of topology and fault location method is difficult to match,which will affect the accuracy of location results.In this paper,a fault location method of distributed network with IIDGs based on Regionalization model is proposed.Starting from the output characteristics of the fault of IIDGs,this paper makes a theoretical analysis of the direction characteristics of the positive sequence component of fault current in the phase to phase fault of distribution network with IIDGs.This paper presents a regionalized model of fault feature which is not affected by the change of topology structure.The analysis results show that the positive sequence component direction of fault current at the first end of fault area is opposite to that at the first end of non-fault area,and the positive sequence component direction of fault current at the upstream and downstream of fault point is opposite,which provides a theoretical basis for the study of fault location of distribution network with IIDGs.Based on the theory of regional model construction principles and regional characteristics,combine with the knowledge of tree structure in graph theory,this paper puts forward the construction method of regional model to realize the construction of regional model.The distribution network with IIDGs is equivalent to the directed tree view,and the node information table is formed according to the connection relationship of nodes.The regionalization model is built by finding the node information in the table.Each region has no branch structure,and no node comparison is needed,thus reduce the comparison times of section positioning.The fault feature of the regional model is not affected by the switching on and off of the components.It has strong adaptability and ensures the effectiveness of the fault location method.In order to improve the adaptability of fault location method to flexible topology,this paper proposes a fault location method for distribution network with IIDGs based on regional model.The phase angle of the positive sequence component of the fault current of each detection point in the fault additional state is obtained by using the Fast Fourier Transform,and the selected area vector and the positioning vector are formed by using the phase angle information.The fault area and the fault section are determined by comparing the difference of the orientation of the selected area vector and the positioning vector.In order to verify the reliability of the fault location method of distribution network with IIDGs based on Regionalization model proposed in this paper,the method is verified by simulation.Considering the influence of various fault factors,a large number of simulation results show that the fault location method has strong adaptability to the topology.The location is fast and the result is accurate and reliable.