The invention relates to an on-line monitoring and controlling method for single-phase ground compensation state in an
arc suppression coil
system, which can effectively estimate compensation state of the
system according to
relative phase relation between negative sequence component I2 of failure current of a failure line and
inductance current IL of an
arc suppression coil, and can correctly regulate the
arc suppression coil, in order to lead the
system into a
resonance state; through comparing I2 with a threshold value, the
resonance state can be effectively estimated and ensure that the
electric arc is reliably extinguished. After the system in the
resonance, the change of the run mode can be effectively estimated according to the change of zero sequence current IN0 of the failure line under the standard
voltage, when IN0 is changed, the run mode is changed, the compensation state can be effectively estimated after the run mode is changed according to the IN0 before changed and the IN0 after changed, and the arc suppression coil can be correctly regulated again to lead the system into a new resonance state. The on-line monitoring and controlling method
dose not need to on-line measure earth
capacitance of a
distribution system, which reduces the regulation of the arc suppression coil during normal operation and contributes to
safe operation of the system, and the load symmetry can not affect the effectiveness of the method at the same time.