Earthing systems are a necessary component of transmission systems. They are essential for the safety and normal functioning of transmission systems. In this article, we tried to explain how to design the earthing system in mobile substations.

Earthing

Earthing systems or grounding systems connect parts of electrical power systems to the ground for the safety reasons and electrical systems’ proper functioning. Earthing systems work by the discharge of electric current into the ground by means of low resistance wires. The earthing is carried by connecting the non-current carrying part or the system’s neutral to the ground.

Neutral Earthing: Neutral earthing is achieved by connecting the neutral of a system to the ground with the help of wires. Such kind of earthing is used in generators, motors and other electrical systems.

Equipment Earthing: Equipment earthing is achieved by connecting non-current carrying equipment to the ground through wires. The equipment can be frames, fences, and towers. In any failure, such as a short circuit, the electric current is passed to the ground and protects the systems from damage.

-Earthing is essential because of the following reasons:

-Earthing projects the people from the short circuit current.

-Earthing provides the easiest escape for the short circuit current.

-Earthing protects the electrical equipment from high voltage surges and lightning discharge from the clouds.

Electrical energy is produced in power stations and the voltage is raised to transmission levels. And the electrical energy is transferred away from the power station with the help of high voltage transmission cables. Then the voltage is reduced from transmission levels to distribution levels to make it available for the consumers. The equipment used for increasing and decreasing voltage is called transformer substations. Mobile substations are the type of substations that can be moved on wheels to the locations where they are needed.

Mobile substations are used for the temporary delivery of power or to work as a backup in emergency services, such as failure of a standard substation in conditions of natural disasters.

Earthing Materials of Mobile Substations

Various kinds of earthing techniques and materials are used in the earthing of mobile substations as mobile substations are placed in temporary or in emergency conditions. So the earthing solutions should be according to the requirements of the places where mobile substations are to be fitted. The most commonly used earthing material is galvanized iron or GI and copper.

Following are the materials that can be used for the earthing of mobile substations:

Earthing pipes or earthing rods: Corrosion resistance roads are buried deep into the ground and they are connected with the wires to the main equipment. Current is passed to the ground and dispersed into the earth through these rods. The length of rods can reduce the earth resistance to a desired value

Earthing strips: Earthing strips come in various sizes. Their width can vary from 3mm to 100mm. The strips have high electrical and thermal conductivity. They can be made of galvanized iron or copper.

Earthing Wires: Earthing wires are widely used in the application of earthing. They have high durability and excellent shock resistance.

Earthing plates: Earthing plates are also made of galvanized iron or copper. They are made to be corrosion-free.  They are buried vertically into the earth.