This paper discusses in detail the practicality of the new package composition.
Using the cost performance ratio of investment, it expounds the low return on investment.
Traditional grounding devices are made of galvanized steel.
low cost. Large footprint. The cost of land acquisition is high. The welding process is backward. Poor stability. The service life is short. Maintenance costs are high.
The use of copper-clad steel composite grounding material takes advantage of the good cavitation effect of copper and the strong magnetic permeability of steel.
Copper-clad steel grounding grids have better high-frequency effusion effects than pure copper and pure steel grounding grids during lightning strikes.
1.Comparison of traditional grounding device materials and new materials
In recent years, with the gradual development of national grid construction projects.
The importance of the quality of the grounding device to the safe operation of the power grid is gradually revealed.
With the rapid development of the electric power industry. Grid capacity is constantly increasing. The fault short-circuit current increases accordingly.
The problems of the grounding device are more and more prominent.
In recent years, it often happens that the grounding device is blown due to the system short-circuit fault.
Electrical equipment in substation operation is often overvoltage due to lightning strikes.
Operating overvoltage causes equipment damage, which is intuitive.
But for the grounding device, the damage of the overvoltage to the ground grid is not intuitive, so we can easily ignore this loss.
If sometimes the power failure time is longer.
The fault current caused the ground grid to burn out in many places.
The high potential in the ground grid poses a threat to the secondary circuit.
Danger to personal safety.
In severe cases, it will cause partial or complete power outages in substations.
Major equipment damage and other consequences.
2. Principle and analysis of grounding load
To put it simply, the grounding problem of the power system is a seemingly simple but actually very complex and crucial problem.
Grounding issues not only have a great impact on personal safety but also on the safety of equipment.
Especially, with the development of the power system and the continuous expansion of the grid scale.
The ground short-circuit current is getting bigger and bigger, and various microcomputer monitoring equipment are widely used.
To sum up, the requirements for grounding are getting higher and higher.
The technical indicators of the grounding device have certain requirements:
Firstly, power frequency grounding resistance
Secondly, the impact grounding resistance
Thirdly, thermal stability
Fourthly, contact voltage
Fifthly, step voltage
Sixthly, ground potential interference
In the power system, many accidents have occurred due to the problems of the grounding device.
For example: The main device is damaged. Substations and power plants are out of service.
It has brought great losses to the safe and stable operation of the power grid.
Therefore, we must pay attention to the grounding problem of the power system.
Both engineering designers and managers need to change old ideas and update new knowledge.
The grounding of the power system should pay attention to the following principles:
- Grounding system design and installation compliance
- The structure of the grounding system must be reasonable
- The grounding resistance value should be as low as possible
- The grounding resistance value must remain stable for a long time
- Have good thermal stability
- Contact voltage, step voltage, and ground potential interference must meet the technical requirements.
- To ensure the service life of more than 30 years
The design of the grounding system requires the following factors
- Regional environment: Try to form a three-dimensional three-dimensional ground network.
- Soil conditions: Try to choose a place with high soil humidity.
3. The advantage of copper clad steel grounding wire
|Comparison||Traditional Grounding System||Copper Clad Steel Grounding System|
|Project costs||The cost of steel is low, but the construction cost is high||The cost of copper-clad steel is higher, but the construction cost is lower|
|Grounding material||Steel||Copper Clad Steel|
|Connection method||Electric welding: bad welding quality。||Exothermic welding: good welding quality|
|Conductivity||Conductivity is not high。||Conductivity is very good, four times that of steel.|
|Anti-corrosion||Steel: 3-5 years|
Galvanized steel: 6-8 years
|Copper Clad Steel: more than 30 years|
|Grounding effect||Unstable performance, high ground resistance.||Stable performance and stable grounding resistance.|
|Service life||5-7 years||more than 40 years|