Cathode protection device and protection method thereof

Abstract

The invention relates to a cathode protection device and a protection method thereof. The cathode protection device comprises a cathode protection constant potential rectifier, a positive power electronic switch set, a negative power electronic switch set, a current transformer and a computer controller, wherein the positive power electronic switch set, the negative power electronic switch set, the current transformer and the computer controller are serious into a protected electric appliance loop; and the computer controller receives sampling information coming from the current transformer, judges the working mode of the cathode protection constant potential rectifier, further controls opening and closing of the positive power electronic switch set and the negative power electronic switch set, transmits a failure reset command to a latch in a timing mode according to the preset time, and clears up a second-stage failure latch signal. The problem that grounding apparatus, like the cathode protection constant potential rectifier, which are connected into a pipe are possibly burnt under the conditions of geomagnetic storms, direct current transmission systems, nuclear electromagnetic pulses and the like is solved.

Description

technical field [0001] The invention relates to the technical field of electrical protection, in particular to cathodic protection devices for power transmission systems and buried oil and gas pipelines. Specifically, it relates to a cathodic protection device and a protection method thereof. Background technique [0002] The DC transmission system in which the geomagnetic storm changes from bipolar operation to unipolar operation causes excessive geomagnetically induced current (Geo-magnetically Induced Current, GIC) in buried oil and gas pipelines, and grounding equipment such as cathodic protection potentiostats It flows to the earth and causes great harm to the grounding equipment connected to the pipeline, such as the cathodic protection potentiostat installed on the pipeline, thus endangering the normal and safe operation of the pipeline. At the same time, the excessively high pipe-to-ground potential makes the cathodic protection fail, causing pipeline corrosion or h...

AI Technical Summary

Problems solved by technology

On March 10, 2012, even if the power supply of the cathodic protection potentiostat for the natural gas pipeline was disconnected from the cathode and anode wiring, it even caused a fire accident in the cabinet

However, due to the large resistance connected in series, the power consumption of the cathodic protection potentiostat is increased, and the design effect of the cathodic protection potentiostat cannot be brought into play.

More importantly, for a specific installation of a cathodic protection potentiostat, it is difficult to determine how much resistance is appropriate in series

If an excessively large resistance is connected in series, the normal design effect of the cathodic protection potentiostat cannot be exerted

If the resistance is too small in series, the protective effect of limiting the overcurrent of the cathodic protection potentiostat will not be achieved, and the cathodic protection potentiostat of the pipeline will still be burned in the event of geomagnetic storm, DC transmission system and nuclear explosion electromagnetic pulse, etc. Grounding equipment connected to the pipeline

Therefore, so far, there is no ideal measure to prevent the grounding equipment connected to the pipeline, such as the cathodic protection potentiostat, from being damaged by GIC

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