Measuring system for shunt vectors of metal frames of large ground grids on basis of wireless transmission

Abstract

The invention discloses a measuring system for shunt vectors of metal frames of large ground grids on the basis of wireless transmission. The measuring system comprises a frequency-variable signal source, a coupling transformer, a frequency-selecting ammeter, a frequency-selecting voltmeter, a current transformer, a wireless communication instrument, a wireless transmitting antenna, a Rogowski coil, a wireless receiving antenna and a frequency-selecting multimeter; the frequency-variable signal source is connected with an input end of the coupling transformer, a branch of an output end of the coupling transformer is connected to a remote current electrode, another branch of the output end of the coupling transformer is sequentially and serially connected with the frequency-selecting ammeter and the current transformer and then is connected with a down conductor, an input end of the frequency-selecting voltmeter is connected with the down conductor of a measured large ground grid, and an output end of the frequency-selecting voltmeter is connected with a remote voltage electrode; an output end of the current transformer is connected with the wireless communication instrument, and the wireless communication instrument is connected with the wireless transmitting antenna; and a port on the frequency-selecting multimeter is connected with the wireless receiving antenna, another port of the frequency-selecting multimeter is connected with the Rogowski coil and encircles a certain metal frame within a region of the large ground grid. The measuring system has the advantage that the state of the ground grid can be accurately evaluated.

Description

technical field [0001] The invention relates to a measuring device for a shunt vector in the electric power industry, in particular to a measurement system for a large-scale ground grid metal frame shunt vector based on a wireless transmission method for measuring ground impedance of a large-scale ground grid. Background technique [0002] In addition to providing a common reference ground for various electrical equipment, the grounding grid of power plants and substations, more importantly, can quickly and effectively discharge the fault current when the system has a ground fault or is struck by lightning, improving the ground potential distribution of the grounding grid and the site , The role of ensuring the safety of primary and secondary equipment and personnel is an important measure to maintain the safe and reliable operation of the power system and ensure the safety of personnel and equipment. [0003] Grounding impedance is an important parameter to characterize the...

AI Technical Summary

Problems solved by technology

In the past, due to the limitation of technical level and testing equipment, in many cases, when measuring the ground network of substations, either the ground wire shunt was not measured at all, or only the modulus of the metal frame shunt was measured, and its phase was not measured.

If the shunt is not measured, the influence of the overhead ground wire dispersion is not considered, and the calculated value of the final test current is too large; when the shunt size (modulus) is measured but the phase difference is not measured, all the shunts can only be regarded as scattered flow outside the ground network , and its direction is completely opposite to the test current injected into the ground grid, the calculated value of the final test current is too small; sometimes the sum of the shunt modulus values ​​measured by each metal structure has even exceeded the injected test current, which cannot Get logical test results

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