Research On Fault Location Of Distribution Network Based On Multi-source Information

Electric energy is one of the indispensable energy sources in people's lives.With the continuous improvement of people's quality of life,people's requirements for power quality are getting higher and higher.As an indispensable link in the power system responsible for the distribution of electrical energy,the distribution network plays an important role in the power system.Once a fault occurs in the distribution network,quickly and timely determining the fault location plays an important role in restoring normal power supply.When a fault occurs in the distribution network,a large amount of fault information appears,such as fault action information,event timing information,fault indicator alarm information,and fault voltage and current data information.How to use these information to fully and quickly realize fault location to restore power supply has important significance.In traditional distribution network fault location,there is insufficient use of fault location information,and the single fault source information is mostly used.The fault location results are mostly concentrated in sections,and the location results are not accurate enough,which is not conducive to the work of emergency repair workers.How to make full use of fault-related information for accurate fault location is the problem studied in this paper.To obtain the precise fault location of the distribution network,the electrical quantity at the time of the fault is generally implemented by the impedance method,the voltage sag method,etc.If directly using a single fault electrical information for fault finding,there is a large amount of calculation and a complex model the problem.Based on this,this paper proposes a fault location algorithm based on multi-source information for a single network.Considering that the fault location is divided into two steps,firstly,the segment location is implemented to reduce the fault finding range,and the segment location mostly uses the switch information;secondly,the electrical quantity information generated in the event of a fault is used to realize distance measurement and positioning.The processing idea of first section and second point realizes the full use of fault information,and has the characteristics of simple calculation model,small calculation amount and excellent calculation speed.When segment positioning is used,switch information is used.Different distribution schemes are proposed due to the difference of the switch quantity information obtained by the distribution network.When the line is installed with protection at the exit of the feeder,and the protection device is also installed in the section,this paper uses the sequence causal network for fault location of the distribution network.The positioning algorithm process is:use the alarm information at the time of failure-protection action information,circuit breaker action information,SOE information to record the time sequence of the event to realize the logical analysis of the alarm information time sequence,so that the false alarm information can be eliminated,and the missing report information can be restored.Restore the real alarm information as much as possible to reduce the inaccuracy of the alarm information caused by uncertain factors and improve the accuracy of the alarm information.Use the processed alarm information to determine the faulty component,establish a causal network model of related components,and perform logical reasoning of the causal network to locate the faulty section.When the distribution network only installs protection at the feeder exit,the previous method cannot locate the fault section,so the fault indicator alarm information is used to locate the fault section.The location algorithm process is:use the alarm information to carry out reasonable logical reasoning to restore the underreported information,for the existence of distributed power,use the different indicators of the fault indicator to give corresponding treatment,establish the fault indicator association table and relationship matrix M,and establish the alarm Vector F,after a certain operation of matrix M and vector F,obtain the corresponding fault section.After the fault section is obtained,the fault location is carried out.The fault location uses the ?PMU measurement value to solve the fault point.The algorithm's solution process is:construct a positive sequence fault additional status network of the distribution network,and use the ?PMU before and after the fault.Obtained voltage and current data,calculate the positive sequence fault additional status network and inject the positive sequence fault current amount,equivalently transform the positive sequence fault additional status network,assume the fault point in the fault section and inject the positive sequence fault at the assumed fault point For the current amount,use the node voltage equation to find the equivalent node voltage in the positive-sequence fault additional state.The method searches for fault points in the fault interval,and finds the fault point corresponding to the minimum positive sequence node voltage spectrum radius that meets the requirements of ranging accuracy through multiple golden section methods,and finally achieves accurate fault location.In summary,the multi-source informatas ion-based fault location algorithm proposed in this paper comprehensively protects circuit breaker alarm information,event timing information,fault indicator alarm information,and ?PMU measurement data to achieve accurate fault location in the distribution network.The algorithm has simple principle and high positioning accuracy,and has good positioning effect after simulation verification.This research is of great significance to the operation and repair personnel to improve work efficiency.