Ground resistance measuring equipment and measuring method for large transformer substation

Abstract

The invention discloses ground resistance measuring equipment and a ground resistance measuring method for a large transformer substation. The device comprises a current electrode, a voltage transformer, a current transformer, a controllable switch KA, a test power supply and a numerical control device. The ground resistance measuring equipment and the ground resistance measuring method for the large transformer substation provided by the invention have the technical effects that ground resistance measuring equipment of a controllable switch is additionally arranged in a current measurement loop, and the device can realize measuring ground stray current and stray voltage, so that the interference of stray current values and stray voltage values can be excluded when the ground resistance is measured, and the accuracy for measuring the ground resistance can be improved; in addition, the device is simple in structure and easy to operate, and a measuring value is not needed to be corrected repeatedly in the process of measuring.

Description

technical field [0001] The invention belongs to the technical field of electric power, and in particular relates to a large substation grounding resistance measuring device and a measuring method. Background technique [0002] With the development of the power system, the grounding short-circuit current is getting bigger and bigger, and the requirements for the grounding of the power equipment are getting higher and higher. With the technological progress of the power system, especially the large-scale use of compact and miniaturized equipment, the proportion of the substation The ground area is getting smaller and smaller, so the grounding resistance of the substation is also required to be smaller and smaller. When the grounding resistance is too large and a grounding fault occurs, the neutral point voltage offset will increase, and it is very likely that the sound phase and neutral point voltage will be too high, exceeding the level required for insulation and causing equ...

AI Technical Summary

Problems solved by technology

When the grounding resistance is too large and a grounding fault occurs, the neutral point voltage offset will increase, and it is very likely that the sound phase and neutral point voltage will be too high, exceeding the level required for insulation and causing equipment damage; it is also directly related to Personal safety of substation operating personnel and substation maintenance personnel; but because the soil has a corrosive effect on the grounding device, as the operating time increases, the grounding device will corrode, which will affect the safe operation of the substation; therefore, it is necessary to strengthen the grounding of the grounding grid. Regular monitoring of resistance

[0003] In the prior art, the general grounding resistance measurement device cannot accurately measure the grounding resistance due to the interference of stray current and stray voltage in the ground network during the test. The process is complicated, and the test personnel work intensively, and problems such as stray current and voltage interference in the power grid cannot be ruled out

Images