CN105112922A - Impressed current cathodic protection system for electric grounding device - Google Patents

Abstract

The invention relates to an applied current cathodic protection system for a power grounding device, which is characterized in that it includes a reference electrode, one end of the reference electrode is buried near the grounding device, and the other end is connected to the reference terminal of the current control device through a reference electrode cable. The positive end of the current output of the current control device is connected to the deep well type anode buried in the ground through the electrode cable, and the negative end of the current output of the current control device is connected to the grounding device buried in the ground through the electrode cable, thus constituting the external current cathode of the power grounding device Protection System. The invention mainly researches an applied current cathodic protection system of a power grounding device, which is suitable for the anti-corrosion protection system of the grounding grid.

Description

Impressed current cathodic protection system for power grounding device

technical field

The invention belongs to the technical field of electric power equipment grounding, in particular to an external current cathodic protection system of a power grounding device.

Background technique

The substation grounding grid is an essential facility for working grounding, lightning protection grounding, and protective grounding. It plays the role of leakage and voltage equalization in lightning protection, static electricity, and fault currents. An important safety barrier for operation. However, the grounding grid has been buried underground for a long time. Due to the chemical corrosion of the soil, electrochemical corrosion and stray current corrosion caused by the leakage of operating equipment, the grounding performance will be reduced, and it cannot withstand sudden accidents such as lightning impact or short circuit. Current and short-circuit current cannot fully diffuse in the soil, which will inevitably lead to an increase in the potential of the grounding grid, causing high voltage on the metal casing of the grounded equipment, breaking down the insulation of the secondary protection device, and even damaging the equipment and disrupting the stability of the grid system.

At present, for the design of the grounding grid, the life of the general substation should not be less than 30 years, and the life of the grounding grid of the important hub substation should be considered as 50 years. However, the corrosion of the current grounding grid makes it as long as 10 years, and at least 3 years will cause damage or even damage. fracture. However, the ground grid project is concealed. The inspection, maintenance and renovation of the ground grid requires a lot of manpower and material resources, which is difficult to operate and expensive. Therefore, as the transmission voltage of the power grid increases, the importance of power grid security and stability continues to increase. Solve the problems of diagnosis, protection and prediction of grounding grid corrosion, improve the corrosion resistance of the grounding grid material itself, ensure the stability of grounding performance, and extend the grounding grid. The service life of the power system and the reduction of the operating cost of the power grid have become urgent issues to be solved for the safe and economical production of the power system.

Contents of the invention

The object of the present invention is to propose an impressed current cathodic protection system for a power grounding device aiming at the deficiencies of the prior art.

The present invention solves its technical problem and realizes by taking the following technical solutions:

An impressed current cathodic protection system for a power grounding device, characterized in that it includes a reference electrode, one end of which is buried close to the grounding device, and the other end is connected to the reference terminal of the current control device through a reference electrode cable, and the current control device The positive end of the current output of the current control device is connected to the buried deep well anode through the electrode cable, and the negative end of the current output of the current control device is connected to the grounding device buried in the ground through the electrode cable, thereby constituting the external current cathodic protection system of the power grounding device.

Moreover, the reference electrode is specifically an Ag/AgCl or Cu/CuSO ₄ reference electrode.

Moreover, the reference electrode near the grounding device is 0.2m-0.4m away from the grounding device.

Moreover, the material used in the deep-well anode is an auxiliary anode doped with high-silicon cast iron and carbon powder, and its component content is: Si: 14wt%-17wt%, Mn: 0.9%-1.2%, C: 1%wt%- 1.2wt%, the rest is Fe, the current density of the deep well type anode in the soil is 8-12a/m ² , and the consumption rate is 0.04-0.15kg/aa.

Moreover, the deep well type anode is buried 50m-60m below the grounding device, and the embedment method is horizontal or vertical.

Advantage and positive effect of the present invention are:

1. The present invention mainly studies an impressed current cathodic protection system for electric grounding devices, which is suitable for anti-corrosion protection systems of grounding grids.

2. The application of the system of the present invention can realize the long-term anti-corrosion protection of the grounding grid, and the general effective protection period of the grounding grid is more than 30 years. At the same time, it can monitor the potential of the grounding grid and the corrosion effect of the grounding grid in real time, so as to carry out Corrosion evaluation and real-time feedback adjustment of parameters.

Description of drawings

Fig. 1 is a schematic structural diagram of the system of the present invention.

Detailed ways

The embodiments of the present invention are described in further detail below in conjunction with the accompanying drawings: It should be emphasized that the embodiments of the present invention are illustrative rather than restrictive, so the present invention is not limited to the implementation described in the specific embodiments. For example, all other implementations obtained by those skilled in the art according to the technical solution of the present invention also belong to the protection scope of the present invention.

An applied current cathodic protection system for a power grounding device, as shown in Figure 1, the system includes a reference electrode 1, a deep well type anode 4, a current control device 3 and a grounding device 2, one end of the reference electrode is buried near the grounding device, The other end is connected to the reference terminal of the current control device through the reference electrode cable, the positive pole of the current output terminal of the current control device is connected to the deep well type anode buried in the ground through the anode cable of the external line, and the negative pole of the current output terminal of the current control device is connected through the external connection The line electrode cable is connected to the grounding device buried underground, thereby constituting the impressed current cathodic protection system of the power grounding device.

In the specific implementation of the present invention, Ag/AgCl and Cu/ _CuSO4 reference electrodes are specifically used as reference electrodes.

In the specific implementation of the present invention, the material used in the deep-well type anode is an auxiliary anode doped with high-silicon cast iron carbon powder, and its composition is Si content 14wt%-17wt%, Mn content 0.9%-1.2%, and C content 1%. wt%-1.2wt%, the current density in the soil is 8-12a/m ² , and the consumption rate is 0.04-0.15kg/aa;

In the specific implementation of the present invention, the deep well type anode is embedded in a medium-deep well, buried 50 meters to 60 meters below the grounding device, and the embedded method can be horizontal or vertical.

In the specific implementation of the present invention, the grounding device adopts a grounding grid;

In the specific implementation of the present invention, the current control device has a constant potential control function, automatically adjusts the output current, and controls the potential of the grounding device to be within the protection range.

In a specific implementation of the present invention, the reference electrode near the grounding device is 0.2m-0.4m away from the grounding device.

working principle

The grounding grid is electrically connected to the current control device through a cable, and constitutes a cathode, and the auxiliary anode is electrically connected to the current control device through a cable, and constitutes an anode to form a complete circuit; when the grounding grid is working, the current control device passes self-tuning Adjust the current parameters so that electrons are continuously emitted from the current control device and flow into the surface of the grounding grid, and the corrosion current on the grounding grid is replenished in real time to complete the cathodic reaction, thereby preventing the grounding grid from self-corrosion.

Claims (5)

1. A power grounding device impressed current cathodic protection system is characterized in that it comprises a reference electrode, one end of the reference electrode is buried near the grounding device, and the other end is connected with the reference terminal of the current control device through a reference electrode cable, and the current The positive end of the current output of the control device is connected to the deep well-type anode buried in the ground through the electrode cable, and the negative end of the current output of the current control device is connected to the grounding device buried in the ground through the electrode cable, thus constituting the external current cathodic protection of the power grounding device system. 2. The impressed current cathodic protection system for power grounding device according to claim 1, characterized in that: the reference electrode is specifically Ag/AgCl or Cu/CuSO ₄ reference electrode. 3. The impressed current cathodic protection system for power grounding devices according to claim 1, wherein the reference electrode near the grounding device is within 0.2m-0.4m from the grounding device. 4. The impressed current cathodic protection system for power grounding device according to claim 1, characterized in that: the material used in the deep well type anode is an auxiliary anode of high silicon cast iron doped with carbon powder, and its component content is: Si: 14wt %-17wt%, Mn: 0.9%-1.2%, C: 1%wt%-1.2wt%, the rest is Fe, the current density of the deep well anode in the soil is 8-12a/m ² , and the consumption rate is 0.04- 0.15kg/aa. 5. The impressed current cathodic protection system for power grounding device according to claim 1, characterized in that: the deep well type anode is buried 50-60 meters below the grounding device, and the embedding method is horizontal or vertical.