The Research On Calculation Of The Impact Of Ground And Measurement Of Impulse Grounding Resistance

Under a proper understanding of the impulse characteristics of grounding devices is the basis for power system lightning protection. According to the problems for the impulse grounding calculation of transmission lines, and the limitations of impulse grounding measurements, In this paper, a lot of simulation calculation had been used in the research of impulse characteristics of grounding devices, and furtter field test and data analysis in the measurments of impulse grounding.At first, under the action of impulse current, the spark discharge effect on the radius of transmission lines tower extended grounding, a non-linear distributed parameter mathematical model was proposed in this paper. This model could simulate the nonlinear characteristics of soil breakdown under the action of impulse current.Then, a algorithm of the transient response - difference method was proposed in this paper. Applying this algorithm to the non-linear distributed parameter mathematical model, the numerical solution of each time the electrical parameters of the points has been obtained. Otherwise,the methods discussed in this paper were applied to analyze the impulse characteristics. Drawn conclusions about the equivalent radius's changes of transmission lines tower under the impulse current.At last, this paper has presented a new method of measuring ground resistance. This method has used in transmission line tower and ground network for the field measurement test. A lot of data has been obtained, helped to establishing the standardization in the measurement of impulse grounding.