Fractional Order Wide-band Modeling Of Substation Grounding Grid

The grounding system is one of the important components of a substation, to whichmuch attention is always paid. Supported by the National Natural Science Foundation ofChina (Grant No.51177048), in this thesis, the numerical methods for performance ofsubstations’ grounding systems in frequency domain are researched. The methodspresented in this thesis are verified by comparing the results with those of experimentsand method of moment.Combined with the fractional identification method and numeric solution to thefractional order differential equation, a grounding systems wideband modeling method isproposed. Comparing with the existing wideband modeling method, the orders of themodel can be reduced effectively. Considering the indispensability of the passivityverification of a system for the transient simulation, a passivity verification method forthe fractional order state-space system is studied and a practical criterion is proposed inthis paper.Lots of measured data are collected by the experiments on the testing groundingsystem, through which the validity and the practicability of the methods in this thesis areadequately testified. Analyzing the influence of dimension of grounding grid andparameter of lightning current to the impulse characteristics of the grid by quantity ofcalculation using this method.