The Research On Some Technique Problems Of The Resonance Ground System In Distribution Grid

In our country, lots of neutral ground method are used in the 6～35kV distribution grids. Of these methods, resonance ground technique is used mostly. But, there are also some problems which have not been settled in the resonance ground system. By a lot of analyses for the medium-voltage distribution networks with different neutral ground techniques, the disadvantages of neutral resonance grounded mode and neutral flexible grounded mode have been proposed by in-depth analyses in this paper. The theoretical analysis and a great deal of simulations have shown the advantages of the new program on limiting the over-voltage of single-phase ground fault, restraining excessive remnant current and detecting faults.Traditional methods for measuring capacitive phase-to-earth current in distribution networks which has been analyzed in this paper. Their drawbacks are presented also. A new method for measuring the capacitive current by injecting signals has been educed in this paper. The hardware and software designs for measuring device have been finished in the paper.