Arc-suppression coil for decentralized compensation

The self-extinguishing of the arc caused by a single-phase grounding fault depends mainly on the amplitude of the residual current at grounding point.To reduce the residual current,the reason of residual current generation in resonant grounding system is analyzed theoretically:the automatic arc-suppression coil can only compensate the zero-sequence reactive current,but not the active current.Simulative calculation points out that,the decentralized compensation is an effective way to reduce the active components of residual current.For 6 10 kV distribution networks in China are wired in △ type and there is no auxiliary neutral point for arc-suppression coil,a new-type arc-suppression coil is developed,which is a three-phase-five-column reactor and the compensation current is controlled by adjusting the gaps of two side columns.It is fitted for decentralized compensation with simple structure.The lab experiments show its fine inductance linearity and effective compensation performance.