Research On Fault Location Technology Of Distribution Network Considering Line To Ground Capacitance

As the link closest to the user side in the power system,the operation state of distribution network will directly affect the power consumption experience of users.With the upgrading of the current power grid,the distribution network is also developing towards a more complex structure.After the fault occurs in the complex distribution system,the accurate fault location result is a reliable guarantee to ensure its stable operation.At present,the continuous development of micro synchronous phasor measurement unit（μPMU）technology provides high-precision synchronous measurement data for distribution network operation analysis.Besides,it also provides reliable technical support for the new fault location method.Under the above background,aiming at the fault location problem of multi branch complex distribution network,this paper proposes a fault location method of distribution network considering ground capacitance.The main research results are as follows:（1）A distribution network topology identification method based on synchronous phasor measurement is proposed.The random forest algorithm is used to screen the measurement data of distribution network according to the importance of characteristics,so that the required measurement information can be reduced on the premise of ensuring the accuracy of distribution network topology identification.On this basis,a distribution network topology identification method based on BP neural network is formed,and the selected variables are used to construct the feature set,so that the neural network can learn the corresponding relationship between the feature set and the topology structure,Thus,when the current new measurement data arrives,it can judge the running topology in the new scene.MATLAB/Simulink is used to simulate the proposed topology identification algorithm to verify the effectiveness of the proposed algorithm.The results of topology identification lay a foundation for the realization of subsequent fault location.（2）Based on the topology identification of distribution network,a fault location method of distribution network considering line to ground capacitance is proposed.This method constructs the fault line model,establishes the fault section location index according to the characteristics of distribution network after fault,judges the fault section according to the topology identification results,and locates the fault between two adjacent measuring devices.Then,considering the uniqueness of fault point voltage,a fault location method based on iterative modification of capacitive current is established,which can judge the faults of main line or branch line,and the fault distance is calculated by using the idea of optimization to obtain the specific location of the fault point.MATLAB/Simulink simulates and verifies the proposed fault location algorithm.The results show that the fault location accuracy is improved after the iterative modification process of capacitive current proposed in this paper.