Research on the compensation mode and new principal-auxiliary arc-suppression coil in the resonant grounded system

The selection of compensation mode and the arc-suppression coil is the main problem in the operation of resonant grounded systems. This paper proposes a new compensation mode that is a combination of presetting mode and following-setting mode, which can do great help to the self-extinction of the instantaneous grounded arcs. In this mode, the arc-suppression coil is preset to some place that is about 15% over-compensation when the system is healthy, and the arc-suppression coil is quickly following-set to the full compensation point when the single-phase-to-ground fault occurs. To demonstrate this, a new principal-auxiliary arc-suppression coil is designed. The auxiliary arc-suppression coil composes of N fine-tuning coils, switched by N thyristors. The inductance of them adopts binary-weave system, which form 2^N compensation values. The results of the 10 kV physical simulating experiments and simulation with EMTP/ATP verify the reliability and validity of this compensation mode and the new principal-auxiliary arc-suppression coil proposed in this paper.