What are Electrical substation ? Defination , single line diagram and Types
What is Electrical substation ?
A substation is part of an electrical generation, transmission, and distribution system. Substations contain different components and equipment to control, convert, step up, or step down the power. Electrical substations play different roles in power systems, some of which are listed below.
Voltage Conversion:
Substations are equipped with transformers that can increase (increase) or decrease (lower) the voltage of the electricity. This voltage conversion is necessary to transmit electricity over long distances and distribute it to consumers with the appropriate voltage level.
Distribution:
Substations play a key role in electricity distribution. They obtain electricity from high-voltage lines and distribute it to homes, businesses and industrial facilities at lower voltages.
Connection and Protection:
Substations contain switches, circuit breakers and safety devices that control the flow of electricity and ensure safety.These devices can isolate faulty sections of the grid, preventing widespread power outages.
Busbars:
The lower-voltage electricity is then sent to a series of busbars, which act as distribution channels for the electrical power.
Protective relays:
Protective relays are used to detect faults in the electrical system and trigger the switchgear to disconnect the affected section of the substation, thus preventing damage to equipment and ensuring safety for personnel.
Monitoring and Control:
Modern power plants are equipped with monitoring and control systems that enable remote control and real-time data collection. This technology helps energy companies manage their networks more efficiently and respond more quickly to problems or outages.
Grid Reliability:
Substations play a key role in maintaining the reliability and stability of power grids. They help balance supply and demand, manage voltage levels and reduce losses in electricity transmission and distribution.
Types of substations:
There are different types of substations, including substations that connect high-voltage power lines and substations that distribute electricity to consumers. Depending on their location and purpose, substations can be outdoor or indoor facilities.
Difference between indoor and outdoor substations
Although both indoor and outdoor substations have the same basic function of converting and distributing electrical power, they differ in terms of their location, design, and uses:
1. location:
Indoor Substations:
These are often found inside of confined constructions or buildings. Environmental elements including weather, temperature changes, and pollution are protected from them.
Outdoor Substations:
These are located in open areas and are subject to weather conditions such as rain, wind, sunlight, and temperature changes.
2. Construction
indoor substations:
They are made with a focus on compactness and frequently use gas-insulated equipment to reduce the amount of space needed. Due to their closeness to structures, they also include fire and safety prevention measures.
Outdoor Substations:
These substations are built to resist external conditions and use air-insulated equipment. They could incorporate defense.
3. Voltage:
Indoor substations:
These substations are installed up to 66kv and required smaller space.
Outdoor substations:
These substations are installed more than 66kv and required larger space.
4. Cost:
cost of indoor substations are less as they require less space and the cost of outdoor substations are very large as they required large amount of space.
5. Examples:
Indoor substations:
The distribustion substation is an example of an indoor type substation.
Outdoor substations:
The grid substation is an example of outdoor substations.
Today we will discuss the distribution substation (33/11 kV), where I just joined as the head of the substation.
- Its a 2×1.00 MVA, 33/11kv substation, so here there are three feeders that are currently harnessed.
- It's an unmanned substation controlled by the SCADA (Supervisory Control and Data Acquisition) system.
- SCADA is software that controls the substation process, collects real-time data, and stores it.
- This substation has three feeders that are currently in working condition and supply 56 villages with a population of approximately 17,800.
- Here, a 33 kV 800 auto-recolser is used.
- It has two power transformers and ONAN (oil Natural and air natural) cooling used.
Single line Diagram:
Here the main supply 33 kv feeder line is coming from generating station ( Bassi)
33 kv main feeder is divided into two substations that is Makriri and bhararoo
Tapping is taken from main feeder to bhararoo substation and the 33kv outgoing line from bhararoo to makriri substation ( outgoing feeder is basically balance the supply chain or we can say interconnected system.
This 33 kv main supply stepdown to 11 kv via power transformers.
There are two busses that are connected by bus coupler each bus have two feeders and each feeder are of 11kv.
There are four feeders , the feeder goes to particular area pole mounted transformer ( pole mounted substation converts 11kv to 3 pahse 440v and after that we take single phase supply from this to our homes.
SCADA control panel meters:
These are electronic trivector meters of incoming feeders and outgoing feeders. These meter record real time data like load power factor fault details and tripping etc. Supervisory control and data acquisition (SCADA) is a system of software and hardware elements that allows industrial organizations to:
- Control industrial processes locally or at remote locations
- Monitor, collect information and data and process real-time data
- Directly interact with devices such as sensors, valves, pumps, motors, and more through human-machine interface (HMI) softwares
