Arc Suppression Method for Single-phase Grounding Fault of Generator Stator Winding

Abstract

The invention discloses an arc suppression method for a single-phase ground fault of a stator winding of a generator, comprising: if a ground fault of the stator winding is detected, acquiring a reference electromotive force and performing detection, that is, applying a clamping voltage to the reference electromotive force so that the neutral point voltage is adjusted to Clamp the voltage, and then judge whether the voltage value at the stator fault coil is zero, if it is zero, select the voltage at the neutral point of the clamp generator as the optimal clamp voltage; if it is not zero, select another reference electromotive force for detection; where , when selecting the reference electromotive force, follow the same branch to detect and analyze from the first coil backward turn by turn; if the coils on one branch have not been adjusted to 0 after the search and detection of the coils, then analyze the other branch of the same phase until the voltage at the faulty coil is adjusted to 0. Through the invention, the voltage at the fault coil can be adjusted to 0, and the problem of single-phase ground fault arc suppression can be solved.

Description

technical field [0001] The invention belongs to the technical field of generators, and in particular relates to a single-phase ground fault arc suppression method for a stator winding of a generator. Background technique [0002] Stator winding single-phase ground fault is the most common type of fault in large generators, and it is often caused by insulation damage between the stator winding and the iron core. Large-scale generator sets at home and abroad generally adopt the neutral point non-effective grounding method to limit the single-phase ground fault current within the allowable range. The protection unit only sends signals without tripping. energy balance. However, the zero-sequence impedance of the neutral point non-effectively grounded system is large, the fault signal is weak, and it is very difficult to extinguish the arc of the single-phase ground fault of the stator winding. During the fault period, the repeated charging and discharging process of the capaci...

AI Technical Summary

Problems solved by technology

However, the existing measures cannot guarantee that the fault current is limited to below the 1A standard required by the regulations under high-resistance to low-resistance ground faults, and they are powerless to deal with intermittent arcing ground faults

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