Study On The Resonant Ground System With Continuously And Quickly Adjustable Arc Suppression Coils

After describing current states and dominating problems of the arc suppression coil (ASC) grounding system in detail, the thesis proposed that the quickly adjustable ASC is able to meet the harsh requirements of the distribution network. However, the existing ASC with the fast adjustment may cause the heavy distort current, for which the application extension of the quickly adjustable ASC is limited. It is rather important for the ASC application extension to develop the ASC, which not only is able to be adjusted quickly, but also causes the little distort current.The solution has not been found how to judge the resonant state during the single-phase grounding existing on-line. In the existing tuning-resonant technique, the inductance of ASC is adjusted for the resonance according to the capacitance of the distribution network in the normal operation. However, this technique exists the disadvantage obviously. The capacitance depends on the configuration of the distribution network. If the configuration changes during the single-phase grounding existing, the capacitance of the distribution should change. But that varied capacitance resulted from the varied configuration cannot be measured in the existing tuning-resonant technique so the distribution network is unable to go back to the resonant state. It is also the question for the ASC grounding system to judge the varying configuration of the distribution network during the single-phase grounding existing and to measure the capacitance corresponding to the changed configuration of distribution network.It is difficult for the selection of the single-phase grounding fault line in the ASC network. Having been studied for many years, for the single-phase grounding directly or through the resistor with the small resistance the selection of the fault line do well. However, for the single-phase grounding through the resistor with the large resistance the selection of fault line gets rather difficult and has no answer to the problem at present.The judgment of the single-phase grounding in correction is the precondition for ASC system working well. The existing judgment for the single-phase grounding is over-simple, which follows the fact that the single-phase grounding fault is detected incorrectly and the over voltage is caused. This is inconvenience for the operation of the distribution network.