Ground ion flow density measurement system for AC/DC parallel powerline and measurement method thereof

Abstract

The invention relates to a system for mensurating the density of an ion current on the ground of an alternating current / direct current parallel electric transmission line and a mensuration method thereof and belongs to the technical field of electromagnetic environment of a high-tension transmission line. The system mainly comprises three parts of an ion current plate, an oscillograph and a computer stored with an ion current density analyzing program, which are connected sequentially, The method comprises the following steps: calibration data of the ion current plat is read; sampling frequency of an oscillograph is arranged; frequency spectrum is carried out on sampling data; peak value frequency is searched; direct current component is extracted; the density of a direct current composition of the ion current is calculated and is subjected to harmonic analysis; the density of an alternating current composition of the ion current is calculated; and the frequency spectrum of the density of the ion current is stored. The system for mensurating the density of the ion current on the ground of the alternating current / direct current parallel electric transmission line is successfully used to mensurate the component of the direct current component and the alternating current component of the ion current on the ground of the alternating current / direct current electric transmission line.

Description

technical field [0001] The invention belongs to the technical field of electromagnetic environment of high-voltage transmission lines, and in particular relates to the development of a ground ion current density measurement system under AC-DC parallel high-voltage transmission lines. Background technique [0002] With the rapid development of power system construction, there are more and more applications of AC-DC parallel transmission in power transmission-intensive areas such as power stations and substations. Especially in the construction of the UHV DC power grid, on the one hand, the DC and AC lines near the converter station exit converge in one place, and the possible paths may be the same. Setting up the AC and DC lines next to each other or even sharing the same corridor can save a lot of land and reduce the difficulty of design; On the other hand, if the newly added long-distance cross-regional DC transmission lines can share the existing AC transmission corridors,...

AI Technical Summary

Problems solved by technology

At present, the measurement device for the above physical quantities is only suitable for a separate DC line or AC line. If it is directly applied to an AC-DC parallel line, it may be difficult to obtain the real value because the AC and DC cannot be taken into account, or the effects caused by the AC and DC cannot be distinguished. source of pollution

[0004] The ion current density under the DC line is generally measured by the ion current plate, but when there is an AC electric field, due to the capacitive effect, an induced current will be formed on the ion current plate, which will affect the measurement of the DC ion current density

It is generally believed that the space charge reciprocates near the wire during the corona discharge of the AC line, and there is no space charge near the ground, but there is a space charge generated by the corona discharge of the DC line near the ground under the AC-DC hybrid line. Under the action of the electric field, non-DC ionic currents will be generated on the ground, and it is difficult to consider these effects using traditional methods

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