Neutral point grounding impedance device of transformer and multipurpose direct current magnetic bias protection method of impedance device

Abstract

The invention discloses a neutral point grounding impedance device of a transformer and a multipurpose direct current magnetic bias protection method of the impedance device. The impedance device is arranged between neutral points of all main transformers in a transformer substation and the ground, and comprises an impedor Z, a lightning arrester A and a by-pass switch K; one end of the impedor is connected with a neutral point of the transformer; and the other end of the impedor is grounded. The impedance device has the benefits that the device is mainly used for the transformer substation; the neutral points of the main transformers in the transformer substation are grounded by the impedance device; direct current magnetic bias current can be effectively inhibited; the short-circuit resistance capacity of the transformer is improved; and damage of ground overvoltage to insulation of the neutral point of the transformer is avoided.

Description

technical field [0001] The invention relates to an impedance device, in particular to a transformer neutral point connection impedance device and its multi-purpose DC bias protection method, which can also be used to improve the anti-short circuit capability of the transformer and solve the problem of poor coordination of "gap + lightning arrester" question. Background technique [0002] The DC transmission project can alleviate the problem of unbalanced distribution of load centers and energy centers in my country, but when the DC transmission single-pole ground circuit is running, the DC ground electrode current will cause DC bias such as increased vibration, increased noise, and local overheating of AC transformers in the vicinity. The magnetic phenomenon will cause problems such as loosening of the tightening parts inside the transformer, disconnection of the winding, damage to the insulating material, and loosening and bending of the iron sheet. If the duration is too lo...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to overcome the shortcomings and deficiencies of the above-mentioned prior art, and provide a transformer neutral point connection impedance device and a multi-purpose DC bias protection method, which are mainly used for transformer DC bias protection, and can also solve the existing transformer resistance. Insufficient short-circuit capacity, prone to damage defects, and solve the problem of poor coordination of the "gap + arrester" protection mode of the existing transformer neutral point insulation

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