As more and more areas become urbanized and city lines expand, the demand for electrical power also grows. To meet this demand, electrical engineers and the city governments are using power generating substations. There are various kinds of substations available for the various types of electrical needs. These can include thermal, atomic and hydro-electric substations, and they generate power according to the available resources of the particular area they function in. However, it is possible that these locations are not close by to a load centre, and the utilization of power can only be done at load centres. Therefore, transmitters are used to transport the generated electrical power from a trans substation to load centres and to carry out this function, vast transmission networks are required.
What is a substation?
A substation is a high voltage electric system that is used to control generators, electrical circuits etc. the main purpose and use of a substation are to convert alternating current (AC) to direct current (DC). Some substations are extremely small in size with an inbuilt transformer and all related switches. Other substations can have a vast network of transformers, circuit breakers, other equipment and switches.
The Different Types of Substations:
Substations can be categorized into a few different types. These mainly include:
- Step-up Type Substations: the power supply of this kind of substation is a nearby production facility. It often utilizes a large transformer unit in order to enhance the voltage levels and transmit them to remote locations. In this kind of substation transmission lines can be replaced by a transmission bus and it can also be used to receive the incoming power which is usually received by the generation plant. The substation can utilize the received power to supply the operation of the apparatus in the plant. The substation also comprises circuit breakers that generate switches along with transmitting circuits in and out of service as per the requirement of the plant.
- Customer Substation: this type of substation caters specifically to business. The business case and the technical requirements depend highly upon the needs of the client. Therefore, no two customer substations are the same and all support varying features according to the clients’ requirements.
- System Substation: substations called system substations to include large amounts of transfer of power. These stations often do not offer a power transformer while others can perform a voltage exchange. These substations often supply the endpoints to a transmission line via switchyards and the electrical energy required for the circuits that supply transformer stations. System substations are important to long term consistency in the supply of electrical power. However, they have to built strategically as it is extremely expensive to build and maintain them.
- Distribution Type Substation: these types of substations are used in situations where the main voltage being distributed is low. Distribution type substations are used to supply the voltage to the consumers via a distribution network. In a distribution type substation, the neutral voltage between any phase will not be higher than 230 volts while the voltage of any two phases will be 400 volts.
- Step-down Type Substation: these kinds of substations are located at different points in a network, and they can connect the different parts of the network. These substations are a source of the distribution lines for sub-transmission. These substations can convert transmission voltage into a sub-transmission voltage. The changed voltage lines can then provide a source for distribution substations. In some instances, the power is tapped from the line of transmission to be utilized in an industrial capacity. In other instances, the power is supplied to distribution substations.
- Underground Distribution Substations: the installation of a substation in an already developed city requires a large amount of space. However, in an urban setting finding this space can be a difficult task at times. This is when substations are built under the ground to decrease the requirement of space. This allows for space above ground to be used for various other constructions like parks or shopping centres. The main idea behind an underground substation is the reduced need for occupied land above ground.
- Switchyard: the main purpose of a switchyard to supply the energy that is being generated at a power plant at a particular level of voltage to a nearby power grid or transmission line. In other words, a switchyard is a mediator between the generation of power and transmission lines, and it helps to maintain equal voltage amongst them.
- 11kV Substation: the main implementation of the 11kv substation is to collect the energy from a production station that is being transmitted at a high-voltage and lower the voltage to a suitable amount for local distribution. The main components included in this substation are lighting arresters, isolators, step-down transformers, circuit breakers and capacitor bank.
- 220kV Substation: the 220kV substation utilizes the highest apparent power which a step-down transformer has the capability to provide. As the name suggests, the received voltage level of this substation will be 220kV.
- 132kV Substation: this is another rank in power provided by the Step-down transformer, and the primary voltage is 132kV. These types of transformers are generally used in transmission type substations where the voltage needs to be stepped-down for additional distribution.
Classification of substations:
It is apparent to see; substations are classified based on the nature of the services they render, the duties they have and their operating voltage. At times they can even be classified based on their importance in the power generating system or their design.
The substations classified by their nature of duties are:
- Step-up substation
- Primary grid substation
- Step down substation
The substations classified according to the service they provide are:
- Transformer substations
- Switching substations
- Converting substation
The substations which are operation based include:
- High voltage substation
- Extra high voltage substation
- Ultra-high voltage substation
The importance based substations include:
- Grid substation
- Town substation
The design-based substations include:
- Indoor substation
- Outdoor substation
- Foundation mounted substation
- Pole mounted substation
These are all the different types of substations being used around the world to transmit power and make power available to the cities and countries. Proper distribution of electricity to both urban and rural areas ensures there is a minimum to a non-existing chance of power outages.