Generator stator single phase grounding protection method

A generator stator, single-phase grounding technology, applied in the direction of emergency protection circuit devices, electrical components, etc., can solve the problems of insufficient sensitivity, and achieve the effect of concise expression, simple calculation, and easy understanding

CN1411116AInactive Publication Date: 2003-04-16TSINGHUA UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2003-04-16
Estimated Expiration
Not applicable · inactive patent

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Abstract

This invention put forward two single phase earth protection methods for generator stator based on zero-sequence voltage fault component, both utilizing that of its terminal and neutral point, in which the first method is to utilize triple-frequency harmonic voltage fault component vector composition to make up the decision basis; the second method is to directly take the sum and difference of random value of the zero-sequence voltage fault component at both sides of its terminal and neutral point as the protect signal and brake signal to detect the stator single phase earth fault by comparing spectrum energy in the data window.
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Description

technical field

[0001] The invention belongs to the technical field of relay protection for main equipment in a power system, and in particular relates to a generator stator single-phase ground fault protection method based on a zero-sequence voltage fault component. Background technique

[0002] The single-phase ground fault of the generator stator has great potential hazards, which may lead to more serious winding short-circuit faults, so the stator winding single-phase ground fault protection is an important part of the generator protection system. There are two main forms of generator stator single-phase ground protection, one is the external power supply single-phase ground protection using external signals, but it requires expensive additional devices and is not widely used; the other is the basic signal using the generator itself Stator single-phase ground fault protection for wave zero-sequence voltage and third harmonic voltage has been widely used because of its si...

Examples

Embodiment Construction

[0033] The principle and specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0034] In principle, because the leakage reactance and resistance of the stator winding of the generator are much smaller than the capacitive reactance of the stator winding to ground, if the influence of the leakage reactance and resistance of the stator winding is ignored, when the generator stator single-phase grounding occurs, the fundamental wave and the third harmonic The zero-sequence simplified circuit of wave fault component can be equivalent to figure 1 circuit in which Z t ,Z n are the equivalent impedances of machine terminal and neutral point respectively, R g is the ground transition resistance, is the voltage at the fault point before the fault. It can be seen from the figure that the fault component of the zero-sequence voltage of the machine terminal and the neutral point after the fault and approximately ...