Generalized DC cathodic protection system and its generalized DC potentiostat

Abstract

The invention provides a generalized direct current cathodic protection system and a generalized direct current constant potential rectifier thereof. The generalized direct current constant potential rectifier comprises a pipe-to-soil potential measurement unit, a controller, an adjustable direct current power supply and a polarity control unit, wherein the polarity control unit can convert direct current voltage output by the adjustable direct current power supply into direct current voltage output which is opposite to the polarity of an interfering pipe-to-soil potential under control of the controller. The system comprises the generalized direct current constant potential rectifiers, wherein two output ends of every two generalized direct current constant potential rectifiers are electrically connected with the external surfaces at the two ends of inlet and outlet buried metal pipeline sections of a compressor station respectively and correspondingly; two earthing terminals of every two generalized direct current constant potential rectifiers are connected with a generalized anodic groundbed; and the buried metal pipeline sections are electrically insulated with the adjacent buried metal pipeline sections. The generalized direct current constant potential rectifier of the system can exert an external stray current interference resistance effect, and can convert the direct current polarity to adapt to eliminate external stray current interference in any polarity.

Description

technical field [0001] The invention relates to the technical field of electrochemical corrosion of buried metal pipelines, in particular to a generalized DC cathodic protection system and a generalized DC potentiostat. Background technique [0002] In 1928, Robert J. Cohen (Kuhn), known as the "father of electrochemistry" in the United States, installed the first set of sacrificial anode protection devices on a long-distance gas pipeline in New Orleans, thereby laying the foundation for the modern technology of cathodic protection. Lay the groundwork. At present, cathodic protection technology is widely used in the field of metal pipeline corrosion. It is very necessary to equip the long-distance oil and gas pipeline with cathodic protection system, which is the basic condition for prolonging the life of the pipeline and ensuring the safe operation of the pipeline. At present, the cathodic protection technology mainly includes three types of protection: sacrificial anode ...

AI Technical Summary

Problems solved by technology

For the existing DC potentiostat that only has unipolar voltage output that can be "positive but not negative", the DC potentiostat has no ability to suppress such stray current interference

[0028] Therefore, the discussion of the stray current interference for the above two situations shows that the "left" and "right" of the prior art DC potentiostat cannot be coordinated. "A device that cannot be "negative" cannot meet the requirements

Therefore, the prior art DC potentiostat does not have the ability to suppress asymmetric stray current interference

[0029] (5) The prior art DC potentiostat control has serious limitations

However, when the pipeline is too long, the ground potential of the interference pipe will increase cumulatively with the increase of the length of the pipeline, and the stray current interference signals of the entire pipeline will be superimposed and "coupled", so that the original DC potentiostat loses the external Suppression of stray current interference

Moreover, the existing DC potentiostat has a unipolar output, which cannot change the DC polarity to adaptively eliminate external DC and AC stray current interference and geomagnetic stray current interference caused by space weather, etc.

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