A DC voltage divider fault monitoring device

Abstract

The invention provides a DC voltage divider fault monitoring device. The DC voltage divider comprises an insulated casing and a high-voltage arm and a low-voltage arm in serial connection and mounted in the insulated casing, wherein the top end of the insulated casing is connected with a high-voltage lead, and the bottom end is grounded. The fault monitoring device comprises a first current sensor, a second current sensor, a secondary voltage dividing module, a data acquisition module and a data processing and merging module, wherein the secondary voltage dividing module, the data acquisition module and the data processing and merging module are sequentially connected; the other end of the secondary voltage dividing module is connected with the low-voltage arm, and the connection part is grounded through a low-voltage lead; the first current sensor is arranged at the bottom part of the insulated casing, and the output end is connected with the data acquisition module; and the second current sensor is arranged on the low-voltage lead, and the output end is connected with the data acquisition module. The technical scheme provided by the invention is high in reliability and wide in application range, the working state of the DC voltage divider can be monitored in real time, and reference is provided for accurately processing the operation fault of the DC voltage divider.

Description

technical field [0001] The invention relates to a monitoring device, in particular to a DC voltage divider fault monitoring device. Background technique [0002] Due to the structure and principle of the DC voltage divider of the DC converter station (actually a resistive DC voltage divider with capacitor voltage equalization, that is, the resistance-capacitance voltage divider), the heat generated by the heating element (resistive voltage divider) As the insulating medium (insulating oil or insulating gas) gathers at the upper end inside the insulator bushing, a larger temperature gradient appears at the upper end and the lower end inside the insulator bushing of the DC voltage divider. Depending on the voltage level, this temperature difference can reach more than 20K or 30K. [0003] When there is a large temperature gradient between the upper and lower ends of the DC voltage divider, under humid environmental conditions such as heavy fog or light rain, the upper outer s...

AI Technical Summary

Problems solved by technology

Due to the presence of dirt on the surface and the wet state of the outer surface, the surface distribution resistance of the outer surface of the insulator bushing is uneven, and the uneven surface distribution resistance of the outer surface of the insulator bushing will lead to uneven distribution of the upper and lower potentials of the insulator bushing. Uniform, causing the electric field strength in the upper part to increase and the electric field strength in the lower part to decrease

When the potential distribution is uneven to a certain extent, flashover phenomenon will occur, and in severe cases, breakdown phenomenon will occur

In addition, because the potential distribution inside the insulator bushing is limited by the forced uniform distribution of the resistor divider, the uneven surface distribution resistance on the outer surface may also cause a very high potential difference between the inner and outer walls of the insulator bushing. Once a breakdown occurs, Permanent damage may occur to the entire insulator bushing

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