Fault Location Based On Voltage Matching Of State Estimation

Distribution network is an important part of power system,and is the last link of power system to customers.Distribution lines cover many areas in urban and rural areas,and the running environment is complex.They are vulnerable to different types of failures such as bad weather,vegetation growth and equipment failure.As the end of the power system,the distribution line is directly connected with the user.The fault of the distribution line directly affects the reliability of the power supply system.About 80% of the power interruptions of the users are caused by the fault of the distribution network.Therefore,it is of great significance to carry out the fault diagnosis research of distribution network,manage the distribution network effectively,reduce the fault time of the distribution network,and restore the power supply quickly to improve the service quality and reliability of the distribution system.This paper mainly takes the area of low automation of distribution network as the research object.In the case of distribution network failure,using the measurement information available in the distribution network and using the state estimation method to solve the problem of distribution network fault location,the specific contents are as follows:First of all,the development of distribution network positioning technology is summarized,and different positioning methods are classified according to different measurement information,and analyzed and compared.The fault types of distribution network are analyzed,and voltage sag is the main line,and voltage sags under different fault types are compared.Then,a fault recognition method based on support vector machine is proposed.By analyzing the voltage sags,a multi-Classification Method of 'one to many' and ‘multiple to many' support vector machines(SVM)is proposed to identify the four types of fault.Finally,the hyperplane of various classification models is established through MATLAB software and RBF kernel function,and the fault recognition method is verified.Finally,a fault location method based on state estimation voltage matching is proposed.All the available measurement information in the distribution network is integrated into the operation of fault location,which not only improves the reliability of the algorithm,but also does not cause errors because of some inaccurate problems.An iterative algorithm based on state estimation is used to locate the fault.First,the fault node is found through the iterative operation of state estimation,and then all the lines connected to the selected node are checked,and the exact location of the fault is found.