A control method for cathodic protection of ground electrode in HVDC transmission

Abstract

The invention discloses a control method for realizing the cathodic protection of the ground electrode of high-voltage direct current transmission, which is improved on the basis of the constant current control mode of the direct current transmission project, and according to the detection result of the positive current of the ground electrode, the deviation of the current value of one pole is positive or negative. Alternate change, realizes alternate cathodic protection of the sending end and the receiving end grounding electrode, reduces the corrosion loss of the grounding electrode, greatly prolongs the service life of the grounding electrode, and solves the problem of serious corrosion of the grounding electrode caused by unbalanced current and other problems . The present invention utilizes the existing high-voltage direct current transmission constant current control mode, and makes small adjustments in this mode, which does not increase the investment cost of the control and protection system, and can greatly reduce the corrosion loss of the ground electrode, prolong the service life of the ground electrode, and can be applied to HVDC transmission in practical engineering.

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 ...

AI Technical Summary

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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