Intelligent Measurement System Of Grounding Grids And The Study Of Fault Diagnosis

The grounding system of substation is an important measure for maintaining Powersystem reliable operation and protecting the safety of operating personnel and electricalequipment. Grounding conductors and lead wires are easy to erode, even break up due topoor welding，the affection of short circuit current, particularly serious soil erosion formany years making worse electrical connection performance of grounding network and willdirectly endanger the safe operation of grid. So, it will be have great practical significanceto test the electrical parameters of grounding grids accurately, assessment the operationalstatus of grounding comprehensively, diagnosis and locate faults of grounding grids.Currently, Imported equipments is popular used for the test of electrical parameters indomestic grounding grids, single indicator such as grounding impedance or connectiveresistance is used to reflect the status of grounding grids, this evaluation method is toosimple, easy to drown the information of local defect. The model of grounding grid analytichierarchy is founded based on fuzzy analytic hierarchy process(FAHP), combining theinitial parameters with the propositional parameters of excess in the standard make up ofthe projects in the bottom of FAHP model. Later，Ratio coefficient of various parametersare successive iteration calculated using Tabu search algorithm.Finally, the score of theparameters are calculated base on the planar linear function adopting the currentmeasurement parameters of the substation grounding grid, Assessment results of thegrounding grid can be derived by taking weights of all parameters.At present, Test equipments for grounding grid are developed base on single-chipsystem, which is lack of good man-machine interaction, leading the workload of record testinformation and organize test report is very large. to solve this problem, this paperdeveloped a electrical parameter test system of grounding grid based on industrial controlcomputer, it can measure the electrical parameters of grounding grid accurately, software isloaded into the test system to record test conditions, control hardware to take a test, theequipment can store massive amounts of test data, Analysis the test informationintelligently as well as generate standardized test report, Achieving standard managementfor the test information of grounding grid. According to several electrical parameters, the grounding grid realized comprehensive assessment, which is objective and scientific.Through test in actual grounding grid, the application value of this research has beenverified.In order to locate the fault of grounding grid, this paper use CDEGS to simulate actualgrounding grid, which is a preliminary exploration of fault diagnosis method based onconnective resistance and surface potential, combined with the phase angle change ofsurface potential.The intelligence measurement system have a high degree of consistent with foreignproduct according to test results, Compared with other equipment, the software equipped tomeasurement system provide powerful functions, easy to operate, greatly simplifies theworkload of record, collation and analysis information in test, realizing intelligent analysisand comprehensive assessment for grounding grid, which has been applied to the statemonitoring of grounding grid in substation. The proposed fault diagnosis method forgrounding grid has reference value for the fault location of actual grounding grid.