Fault Mismatch Based Fault Location In Distribution Networks With Renewable Energy Sources

With the rapid development of new energy technologies,the distributed generation of power generation,such as solar and wind energy,is permeated and massively connected to the grid,which bring some impacts on the distribute network.What's more,the trend of the distribution of the power grid is changed by one-way flow to two-way flow,and the power grid trend and topology are more complex.At the same time,due to the randomness and volatility of new energy generation,the stability of the network is reduced and the power grid is more vulnerable.After all of these lead to new energy power generation in a distributed access,power grid is more prone to failure,which limits the development of new energy at the same time,also for a new challenge to fault location technology.Therefore,including the new energy distribution network grounding fault as the research object,through the analysis of the change before and after the fault current characteristic and rule,based on fault current fall fault area rapid positioning method,and the fault node localization method based on the fault degree of mismatch,this paper can achieve rapid and accurate fault location.The main work of this article is as follows:First of all,this paper analyzes the regularities of distribution,clears about the net power supply,power current,charging current line itself and the balance of the relationship between the node load current.Establishes the load model based on current and the current distribution model of distribution network,which analyze the feasibility of fault location method based on the current.Secondly,based on the small,determined measurement nodes in the distribution network,the distribution network is divided into both ends contains measuring equipment area network and single-ended contains measuring equipment area network,and establish the corresponding current distribution model,describe the relationship between regional networks within the current balance.This paper puts forward not only the current drop criterion,which realizes the rapid positioning of the fault area,reduces the fault locating range,and partially excludes the suspected fault nodes,but also the method of estimating the fault ground current of the fault of the meter and load current fault.Thirdly,to analyze the influence of new energy access location and access scale on the voltage and current of the distribution network,the distribution model of the distribution network of the new energy distribution network is established,the method of recursion and iterative calculation of current distribution,voltage and load current in the regional network is proposed.What's more,this paper puts forward the criterion for the fault mismatch of the node locating fault,and can locate the fault node accurately when the ground resistance is large.At last,in the context of different nodes,different fault types,and different ground impedance,the applicability of the new energy distribution network is verified by means of the localization method of the former.After the analysis of the characteristics and reasons of simulation data,and the verification of the accuracy of the fault node localization method,the method's accurate positioning fault nodes and support to ensure the safe and stable operation of the power grid in the new energy distribution of single phase and two phase ground fault occurs has been validated.