Capacitance current measuring method of phase-control type arc suppression coil

Abstract

The invention relates to a capacitance current measuring method of a phase-control type arc suppression coil. The method is based on the phase-control type arc suppression coil with a filtering circuit and specifically includes the following steps that firstly, when the phase-control type arc suppression coil is normally operated, a primary portion of the phase-control type arc suppression coil is equivalent to a primary capacitor connected in a power grid main circuit; secondly, the power grid main circuit is equivalent to a measuring branch circuit connected between a neutral point and the ground in series; thirdly, partial voltage measurement is performed, and a grid three-phase over ground capacitance value is calculated; fourthly, a capacitance current value of a system when the system is connected with the ground in a one-phase mode is calculated by combining the over ground voltage value of the neutral point when the system is connected with the ground in the one-phase mode. According to the phase-control type arc suppression coil based on the filtering circuit, the partial voltage measurement method is adopted, the grid three-phase over ground capacitance value is calculated and the capacitance current when a grid power is connected with the ground in a one-phase mode is accurately measured and calculated, and a reliable guarantee is provided for providing moderate compensating currents by the arc suppression coil.

Description

technical field [0001] The invention relates to the technical field of distribution network grounding, in particular to a capacitive current measurement method of an arc suppression coil. Background technique [0002] With the increase of the capacity of the power grid, the extension of the distance, and the gradual increase of the voltage level, when a single-phase ground fault occurs in this case, the arc formed by the ground capacitance current at the fault point cannot be extinguished by itself, and the overvoltage generated by the intermittent arc will often cause accidents. Expansion, significantly reducing the reliability of power system operation. At present, in my country's medium and low voltage distribution network systems, the neutral point is often grounded through the arc suppression coil for arc extinguishing, which can automatically eliminate instantaneous ground faults and ensure the normal operation of the power system. [0003] Phase-controlled arc suppre...

AI Technical Summary

Problems solved by technology

Although this technology can eliminate harmonics better, its filter circuit is more complicated and difficult to realize in practical applications; and the phase-controlled arc suppression coil still uses the displacement voltage method to calculate the capacitor current, which cannot eliminate the use of this method. Defects in the calculation of the three-phase-to-earth capacitance reactance in the normal operation of the power grid by this method

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