Study On Anxi 10kV Distribution Network Fault Monitoring And Positioning System

To shorten the time spent in shooting,isolating and repairing any fault of the distribution network lines,improvement must be made to achieve automation of the distribution network of Anxi.Although the traditional proposal for automation of distribution network is highly reliable,it has such disadvantages as difficulty in equipment installation,high investment cost,long construction period and the possibility of increasing power supply line faults and potential risks.In addition,it is impracticable to implement the proposal due to the limited fund of Anxi power company for improving the distribution network and the large amount of complicated distribution network lines of the jurisdiction.To solve these problems,the paper makes an improvement to the traditional fault positioning system in combination with the latest domestic and overseas methods of addressing faults and the related experience.Since the distribution network-based neutral grounding system of Anxi is considered the arc suppression coil grounding system,the paper analyzes the current methods of localizing various 10 kV distribution network faults and makes an in-depth study on the principle of diagnosing short-circuit and single-phase grounding faults.Through the foregoing analysis,based on the traditional distributed fault positioning system,the paper puts forward an improvement plan to achieve Internet-based intelligent distribution and introduces the operation principle of fault positioning terminal,data acquisition unit and back-end master station in the system and the related software and hardware design.The paper describes the following solutions against such problems as installation difficulty,low accuracy and high cost in relation to the traditional fault positioning system:(1)On the basis of the traditional principle of localizing fault indicators,the system tests phase faults with the over-current method and judges single-phase grounding faults in combination with the test on the peak current of the transient capacitance of lines and the information of the grounding line selection device faults in the substation,forming a mature and highly practicable fault diagnosis theory.Furthermore,the system tests software using the circuits of testing hardware faults,thus ensuring the sensitivity and reliability in an effective manner.(2)The positioning terminal is charged with a card line and the data acquisition unit is charged by a solar panel.The two communicate with each other through radio frequency,with the built-in parts not electrically connecting with the distribution network lines in a direct manner,solving such problems as difficulty installation and long construction term.(3)The system makes a sampling monitoring on the line voltage and current with the open-type current transformer and the method of measuring the voltage of the space-based electric field,saving the expense for CT and PT lines and reducing the investment cost.(4)The parts of the system communicate with each other in a wireless manner,each of which is independent of the other,making it convenient to expand the system.Once the switch telemetry signal and control signal of the pole mounted switch of the lines connect to the main system,the "three-remote" function of the distribution network is achievable.At last,through simulation and actual running tests,the paper proves that the improved system has such advantages as high reliability,flexible configuration,convenient expansion and low cost and greatly improves the production and operation efficiency of Anxi power company,so that it is practicable to apply and promote the system for the purpose of distribution network fault testing and positioning in the future.