Algorithm And Research On Fault Location Of Distribution Network Based On PMU

With the development of complex and intelligent power grid structure,the current power grid monitoring and management system SCADA/EMS has been unable to meet its management needs.Therefore,it is necessary to improve the traditional power grid monitoring and management system to make it reach a higher level in terms of management efficiency and management quality.The application of wide-area measurement system provides a lot of help for the monitoring and management of power grid.The key component of this system is the synchronous phasor measurement unit(PMU),which has high cost and difficult management and is difficult to be applied to each bus node in the power grid.Therefore,it is necessary to optimize PMU distribution points according to the monitoring target of power network structure,so that it can achieve the effect of dynamic monitoring and better control the cost.In this paper,the PMU configuration model is studied and designed,and it is proved that only a few PMUs are needed to meet the full observability requirements of the power grid.In addition,considering that the system has many different operation states,this paper designs a unified optimization configuration algorithm based on 0-1 integer programming,which can be applied to the PMU configuration problems of various operation modes.For example,there is no PMU placement problem that zero injection nodes are completely observable,and the PMU placement problem that the system can still observe when line N-1 failures are considered.According to the actual situation of power grid operation,a multi-factor and multi-objective allocation method is designed,which can obtain different feasible solutions to improve the model and apply it to the configuration of power grid PMU.At present,the PMU configuration mainly uses the phased configuration method.In practice,the PMU configuration method based on weight ratio can be adopted according to the external environment and economic conditions.In this paper,a new method for fault location of distribution network based on PMU is proposed.At the very beginning,this method needs to identify the types of faults.The three-phase current and zero sequence current generated during faults are taken as the analysis basis.On this basis,we will locate the fault.The synchronous voltage and current data collected by PMU in the system are used to explore the fault line.Therefore,we will get a series of suspected fault points and calculate the fault distance.Then,according to the synchronous voltage and current data measured by PMU at both ends,the phase relationship between the two data is determined,and the points that are not faults are screened out to determine the final location of faults.Next,use Matlab simulation software to verify.A brief model of the distribution network is built on the software,and the voltage and current data required by the simulation can be measured by the actual PMU module.The software is used to realize the designed algorithm,and then to judge whether the algorithm is accurate.The simulation results show that the accuracy of this algorithm is very high in the case of single-phase grounding,two-phase grounding and other faults.It is possible to resist interference of general factors and need not to consider when and where there is a failure,the kind of failure.Simulation results show that the proposed method is efficient and useful.