| The performance of the power system grounding grid is one of the important factor,affecting the safe and stable operation of the power system, and the safety of electricalequipment and staff. Based on the security diagnostics and performance assessment ofcorrosion grounding grid, Timely and accurate understanding of the operating status of thegrounding grid to ensure that grounding grid ground efficacy and safety has importantengineering significance.Based on the research of fundamentals that affect the safe and stable operation of thepower system, the indicator system evaluating the safety of grounding grid is proposed,including touch voltage, step voltage, grounding resistance, electrical integrity, the grounddeflectors corrosion state, grounding grid overall corrosion state. The measurement andcalculation methods and safety standards of each index factor are also analyzed andsummarized.In order to assess the safety performance of the corrosion grounding grid, a fuzzycomprehensive evaluation model of grounding grid security based on fuzzy analytic hierarchyprocess. The weight values of grounding grid touch voltage, step voltage, groundingresistance, electrical integrity, the ground deflectors corrosion state, grounding grid overallcorrosion state are calculated based on fuzzy analytic hierarchy process. And the optimalsecurity degree and membership of the single index factor are analyzed, forming everyfactor’s safety level evaluation matrix. Finally the weight value and evaluation matrix of eachindex factor are synthesized based on fuzzy comprehensive evaluation mathematical model,to get the evaluation results of the grounding grid overall safety level.As an instance analysis, the grounding grid overall security posture analysis and singleindex factors safety assessment calculation are carried out for a110kV substationexperimental grounding grid of Shaanxi Electric Power Research Institute, the results show that the theory and the proposed method is correct and feasible. |
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