Substation Defined
A substation is an integral component and a subsidiary station of an electrical generation, transmission, and distribution system.
It is a facility that contains high voltage electrical equipment for switching, protection, and control of the electricity being transmitted by power lines.
It transfers energy from where it is generated to areas that need it. This process involves several different types of equipment which are described below.
Components of a Substation
The four essential components are the power transformer, circuit switches, circuit breakers, and capacitors.
Substation Transformers
A transformer is an electrical device whose performance is measured by the voltage level: it steps up or steps down. A substation transformer transfers electricity through its coils to its electrical equipment.
The first step of this process is to step down the voltage level from a transmission line to one user at the local substation.
This happens as the electricity travels from the high voltage transmission line towards a closer transformer, which is stepped down for delivery to other equipment.
In addition, there are other transformers present that measure and monitor voltage levels and provide data for reports.
Circuit Switches
The circuit switches at a substation allow electricity to move from one channel. To do this, it must open and close.
Circuit Breakers
The circuit breaker is an electrical switch designed to protect an electrical circuit from damage caused by overloading or short circuits. When unexpected surges or faults occur, this interrupts the flow of electricity.
It is usually composed of a spring, an operating mechanism, and a fuse.
There are two main types: a thermal/magnetic breaker, which uses a bimetallic strip, and a current operated mechanism to sense the level of current going through it which senses excessive heat or electrical arcing.
The other type is an electromechanical breaker, which senses the current through an operating mechanism, most commonly using coils and magnets.
Capacitors
A capacitor stores energy in an electric field. It is a passive two-terminal electrical component that improves the quality of electricity supply to the end-user.
It smoothens the voltage depressions caused by electricity surges and filters out voltage distortions.
Capacitors are used in power distribution systems as well as in carbon-film resistors. They are available in different values, with the most common being .02μF, .05μF, and 1μF.
Types of Substation
There are several types of Substation; the most common types are Step-Up Substation, Step-Down Substation, Distribution Substation, and Underground Distribution Substation.
Step-Up Substation
A substation that increases voltage is called a "step-up" substation. This type of substation transfers electricity from one transmission line to another closer to the local transformer.
Because the voltage level is increased, the amount of power being transferred becomes greater.
Step-Down Substation
A substation that decreases voltage is called a "step-down" substation. This type of substation transfers electricity from one transmission line to another, closer to the power's end-user.
This process requires the energy level to be reduced, and therefore less power is transferred over a shorter distance.
Distribution Substation
A distribution substation is an integral part of any power distribution system. It transfers electricity from a high voltage line to the lower voltage level needed for homes and businesses. This Substation is located near the end-users.
Underground Distribution Substation
Underground substations, located near the end-users, are composed of all metal-enclosed switchgear.
These units help control the flow of electricity to customers at a local level. The advantage of underground units is that they provide protection from harsh weather conditions and prevent power surges that may degrade equipment.
Importance of Substations
Substations make it possible to get electricity from large generation sites to areas that need the energy. The following are the vital roles substations play in the electrical system:
- It ensures a sufficient electricity supply for all customers.
- It changes the voltage to an appropriate level as needed.
- It compensates for system voltage changes, regulating it.
- It eliminates electrical surges from the system.
- It connects the communication signals in the circuits.
- It measures the quality of the electricity flowing through the circuits.
- It serves as equipment to switch the transmission and distribution circuits to and from the grid system.
- It serves as the connection of the electric system from one facility to another.
Things to Consider for Substations
Several things need to be considered when planning to have a substation.
The most important are the type of equipment, soil conditions, and land-use restrictions around it.
These considerations will affect how much space is required for all the equipment to be housed at the Substation.
Advantages and Disadvantages of Substations
Both advantages and disadvantages come into play when considering having substations. Here are some of them:
Advantages
- It brings electricity to areas that need it, so people do not have to install their utility poles, and substations are less expensive to construct.
- Its equipment is more reliable than distribution systems in rural communities.
- Electric companies pay reduced taxes because the land contains a lot of infrastructure for delivering electricity.
Disadvantages
- It causes the unsightliness of picturesque landscapes.
- It has a high vulnerability to potential terrorist attacks.
Final Thoughts
Substations are a crucial part of the power distribution system for any electric company. Without substations, homes and businesses would need to install their own utility poles, which are expensive.
Substations also provide more reliable electricity than rural utility systems, and less money is spent on land since it contains infrastructure for delivering electricity.
On the other hand, substations do not look attractive in scenic landscapes and can be vulnerable to terrorist attacks.
FAQs
1. What are the different types of substations?
There are four main types of Substation: step-up, step-down, distribution, and underground distribution.
2. What is a distribution substation?
It transfers electricity from a high voltage line to the lower voltage level needed for homes and businesses.
3. What are some things to consider when designing a substation?
The most important thing to consider when designing a substation is the type of equipment, soil conditions, and land-use restrictions. These considerations will affect how much space is required for all the necessary equipment to be housed at the substation.
4. What are some advantages and disadvantages of a substation?
The main advantage is that it brings electricity to areas that need it, so people do not have to install their utility poles, and substations are less expensive to construct. Disadvantages of substations include the unsightliness of picturesque landscapes and the vulnerability to potential terrorist attacks.
5. What is a substation?
It is an appropriate place to transform voltage from high to low to be used in homes and businesses. With a substation, people do not have to install their utility poles.
