Control method for cathode protection of high-voltage direct-current transmission grounding electrodes

Abstract

The invention discloses a control method for cathode protection of high-voltage direct-current transmission grounding electrodes. Improvement is performed on the basis of a direct-current transmission project constant current control manner, according to forward current detection results of the grounding electrodes, first-electrode current value deviation changes to be positive and negative alternately, alternate cathode protection of the sending end and receiving end grounding electrodes is achieved, corrosion losses of the grounding electrodes are reduced, the service life of the grounding electrodes is greatly prolonged, and the problem that the grounding electrodes are seriously corroded due to unbalanced current and the like is solved. The existing high-voltage direct-current transmission project constant current control manner is used, the manner is finely adjusted, the investment cost of a control protection system is not increased, the corrosion losses of the grounding electrodes can be greatly reduced, the service life of the grounding electrodes is prolonged, and the control method can be applied to a practical high-voltage direct-current transmission project.

Description

technical field [0001] The invention relates to the field of high-voltage direct current transmission ground electrode protection, and more specifically relates to a control method for high-voltage direct current transmission ground electrode cathodic protection based on ground electrode current detection. Background technique [0002] At present, most of the high-voltage direct current transmission systems put into operation in the world are two-terminal direct current transmission systems, that is, one end is a rectifier station and the other end is an inverter station. Usually its operation mode includes bipolar operation, unipolar earth loop operation, and unipolar metal loop operation. Among them, in the operation of the unipolar metal return line, the ground electrode plays the role of the front neutral point potential; while in the operation of the bipolar and single pole earth return lines, the ground electrode not only plays the role of the front neutral point, but ...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a control method for realizing the cathodic protection of the high-voltage direct current transmission ground electrode in view of the problem that the grounding of the direct current transmission project is easily corroded, thereby affecting the service life of the ground electrode. Improvement on the basis of the current control function can realize cathodic protection for the grounding electrodes at the sending end and the receiving end under bipolar operating conditions, thereby prolonging the service life of the grounding electrodes at the sending and receiving ends

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