Pulse width modulation based cathode protection method and protector thereof

Abstract

The invention relates to a pulse width modulation based cathode protection method. The pulse width modulation based cathode protection method comprises the following steps: firstly, connecting a buried pipeline facility by adopting a pulse width modulation polarization power supply; secondly, setting a cathode protective potential to a predetermined value; thirdly, generating a pulse width modulation signal according to cathode protective potential value; fourthly, driving the pulse width modulation polarization power supply by the pulse width modulation signal; fifthly, measuring output voltage of the pulse width modulation polarization power supply, measuring output current of the pulse width modulation polarization power supply; sixthly, measuring cathode protective potential, relative to a reference electrode, of the buried pipeline facility; a pulse width modulation based cathode protection device is characterized in that the pulse width modulation polarization power supply is connected with an output current measuring device and an output voltage measuring device, the pulse width modulation polarization power supply is connected with a buried facility, an auxiliary anode and an on-off controller, a control circuit is connected with a feedback signal controller by virtue of a protective potential setting device, and a cathode protective potential measuring device is connected with a buried reference electrode by virtue of a copper sulphate reference electrode impedance converter, so that size is small and control accuracy is high.

Description

technical field [0001] The invention belongs to the technical field of corrosion and protection, and in particular relates to a pulse width modulation-based cathodic protection method and a protection device thereof. Background technique [0002] In oil and natural gas storage and transportation, most of the equipment used, such as pipelines, are buried below the ground and are corroded by the soil medium; the bottom of the oil storage tank is also in contact with the soil medium and is corroded by the soil medium. The corrosion of steel pipes and storage tanks in the soil environment is very serious. Once perforation occurs due to corrosion, resulting in leakage accidents, it will cause huge economic losses. It is necessary to stop the transmission and repair and repair the equipment. The leakage of the transmission medium will also cause environmental damage. severely polluted. In order to prevent corrosion of metal equipment for transporting or storing oil and natural ga...

AI Technical Summary

Problems solved by technology

However, the SCR adjustment produces high ripple and serious noise interference, which has a certain impact on the cathodic protection effect. In addition, the SCR rectifier will generate harmonics to the power grid due to its inherent input characteristics, resulting in "pollution" of the power grid, especially is the use of bulk rectifiers

Usually, the power factor of the thyristor type potentiostat is low, below 0.7, so it consumes a lot and consumes a lot of electricity at the same active power.

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