How Electric Substations Work
Electricity plays an essential role in everyday life. It powers our homes, offices, hospitals, and schools. We depend on it to keep us warm in the winter and cool in the summer, charge our phones and binge our favorite TV shows. If the power goes out, even briefly, our lives can be disrupted. The system that delivers your electricity is often described as the most complex machine in the world, and it’s known as the electric grid.
How Does the Electric Grid Work?
The electric grid is so complex because we all use different amounts of electricity throughout the day, so the supply and demand for electricity is constantly changing. For example, we typically use more electricity in the mornings when we’re starting our day, and in the evenings when we’re cooking dinner and using appliances. Severe weather and other factors also impact how much electricity we need.
Power plants can be thought of as factories that make electricity using various energy sources, like natural gas, solar, wind and nuclear energy. Across the U.S., more than 11,000 power plants deliver electricity to the grid.
To get the electricity from power plants to you, we need a transportation system. High-voltage transmission lines act as the highways for electricity, transporting power over long distances. These lines are supported by massive towers and travel through vast landscapes, connecting power plants to electric substations.
Substations are like pit stops along the highway, where the voltage of electricity is adjusted. They play a crucial role in managing power flow and ensuring that electricity is safe for use in homes and businesses.
Once the electricity is reduced to the proper voltage, it travels through distribution power lines, like the ones you typically see on the side of the road. Distribution lines carry electricity from substations to homes, schools, and businesses. Distribution transformers, which look like metal buckets on the tops of power poles or large green boxes on the ground, further reduce the voltage to levels suitable for household appliances and electronic devices. After traveling through transformers, electricity reaches you––to power everyday life.
Electric providers must continuously monitor the electrical system to maintain a stable and reliable grid. The system must also adapt in real-time to fluctuations and unexpected events. A critical element in this infrastructure is the electric substation, which plays a vital role in ensuring efficient power distribution.
What is an Electric Substation?
When talking about our vast power grid, its essential to understand the role electric substations play. Distribution substations act as the heart of our electrical system, feeding our members electricity at the amount they need, when they need. Basically, an electric substation is a control and conversion center for electric power.
Why Do We Need Electric Substations?
Electricity is initially generated at a power plant. However, it is generated at too high a voltage to be distributed directly to members. This is where electric substations are crucial. An electrical substation receives electricity from a power plant or distribution center and then changes the voltage level of the electricity to meet the needs of different users when they need it. The substation also allows for direction and control of the electricity. The current can be split into multiple routes, redirected, or even shut down much more easily at a substation.
What Equipment is in a Substation?
Electric substations are generally fenced off and secured due to the danger high voltage electricity presents. There are different types of substations and variations between them, but here is some of the basic equipment found at a substation.
- Control Building
The control building houses relays that acquire readings from different devices and control the circuit switcher for sub protection. The battery system is in the control building and feeds low voltage out to operate different controls.
- Circuit Switcher
The circuit switcher is designed to open the incoming circuit from the transmission line if there is a fault inside the station. This offers high side protection for the equipment in the substation.
- Transformer
The main function of the transformer is to change the power plant voltage from transmission voltage, which we then use to push the electricity out to our members miles away.
- Regulators and Breakers
Regulators adjust voltage in small increments up and down as the station's load rises or falls. Breakers protect outgoing phase lines and equipment by opening the circuit mechanically if a fault happens.
- 3 Phase Feeders
After changing the voltage, the electricity is pushed out onto 3 phase lines to provide the members with service. Cooperatives usually try to balance the load between the individual phases when feeding a single-phase service as well as feed large facilities with large motors needing 3 phase power.
In summary, electric substations are a crucial part of our electric grid. They take the power generated at a power plant and change the voltage to the correct amount allowing it to be pushed out to homes and businesses. It also allows for greater control of the electrical routes and provides several safety stops and breakers along the path.