A method and device for automatic tuning of arc suppression coil based on voltage regulator

Abstract

The invention discloses an arc suppression coil automatic tuning method and device based on a voltage regulator. The method includes: maintaining the inductance value X of the arc suppression coil inductance l unchanged, the neutral point zero-sequence voltage U is changed by the voltage regulator 0 First adjust to kU 0 ;The adjusted neutral point zero-sequence voltage kU 0 Added to both ends of the arc suppression coil inductance to change the compensation current value. The device includes: a grounding transformer, an AC / DC converter, a DC / AC converter, an output transformer, a controller, a voltage transformer and a fixed arc-suppression coil inductance; the controller is used to control the output terminal of the output transformer to generate and neutralize Neutral point zero-sequence voltage U 0 A synchronous variable voltage source is added to both ends of the fixed arc suppression coil inductance to change the compensation current value. Through the invention, the cost is greatly reduced, and the resonant overvoltage that may occur when the residual current is small in the traditional method is avoided.

Description

technical field [0001] The invention relates to the technical field of arc suppression in electric power systems, in particular to an automatic tuning method and device for an arc suppression coil based on a voltage regulator. Background technique [0002] my country's voltage 6KV ~ 35KV power grid adopts a neutral point ungrounded power supply system. Its advantage is that after a single-phase ground fault occurs, it is allowed to continue to run for 2 hours, which will not cause power failure for users and improve the reliability of power supply. However, with the increase of the scale of the power grid, especially the extensive use of cables, the ground capacitance current is too large when the single-phase ground fault occurs in the power grid. Excessive capacitive current also prevents the grounding arc from self-extinguishing and easily generates a higher multiple of the arc-to-ground overvoltage, which seriously threatens the safe operation of the power grid. Therefo...

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Problems solved by technology

[0004] At present, there are mainly the following methods for automatic tuning of the arc suppressing coil: (1) the method of adjusting the number of turns of the inductance through the on-load tap changer switch, this method cannot continuously adjust the inductance; (2) adjustable air gap or movable The iron core method relies on mechanical means to adjust the dynamic response speed of the inductance; (3) the DC bias method and parallel transformers at both ends of the inductance, and connects a capacitor controlled by a thyristor on the low voltage side to change the equivalent inductance value, etc. Harmonic interference will be generated when adjusting

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