Method for measuring resistance of ground wire of transformer

A measurement method and grounding wire technology, applied in the direction of grounding resistance measurement, etc., to achieve the effect of improving accuracy, reducing influence and improving precision
CN101949979AInactive Publication Date: 2011-01-19GUODIAN LONGYUAN ELECTRICAL
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
GUODIAN LONGYUAN ELECTRICAL
Publication Date
2011-01-19
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention provides a method for measuring resistance of a ground wire of a transformer. The method comprises the following steps of: 1) allowing the ground wire of the transformer to pass through an N-turn excitation coil and an n-turn response coil, and measuring an interference voltage value Ug output by an output end of the response coil under the condition of not adding excitation voltage signals at the end of the excitation coil; 2) adding an excitation voltage signal Ui with specified frequency and specified amplitude at the input end of the excitation coil, wherein the Ui is coupled to the ground wire so as to generate induction current I on the ground wire; 3) generating response current Io which is equal to I / n by the current I on the ground wire through the response coil, and measuring induction voltage Uo which is equal to Io*Ro and output on the response coil at the time, wherein Ro is the resistance of the output end of the response coil; and 4) obtaining the amplitude of the ground resistance Rx through a formula Ui*Ro / (N*n*(Uo-Ug)). The method of the invention improves the accuracy of measuring the resistance and reduces the influence of the current on the ground wire on the measured resistance.
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Description

technical field

[0001] The invention belongs to the technical field of transformer grounding wire resistance measurement and relates to a method for improving the measurement accuracy of grounding wire resistance. Background technique

[0002] During the construction of smart grid, the power supply department of the State Grid has higher and higher requirements for the assessment of power supply quality. Whether the grounding wire of the transformer in the Taiwan area is connected well or not is directly related to the safe use of electricity of the user. If the grounding is not good, it will damage the user's electrical equipment, and it may cause a fire, which will cause serious losses to people's property and life safety. Therefore, monitoring the resistance of the grounding wire is an important measure to ensure the safe production of electric power.

[0003] The equipment for real-time monitoring of grounding resistance in the prior art can monitor the resistance valu...

Claims

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