At the substation, there are step-down transformers for bringing the high voltage down to lower voltages for distribution uses. At generating stations, a GSU transformer is required to increase the voltage level for transmitting electricity over long distances. In order for electric transmission to take place, it requires voltage transformations at two substations, (1) the generation station (voltage step-up) and (2) the substation (voltage step-down) where distribution takes over.
![electric grids electric grids](https://blog.arcadia.com/assets/2015/07/grid.png)
The electricity can be transmitted at various voltage levels. Figure 3 below shows a picture of a typical 3-phase transmission system with transmission towers and transmission lines.įigure 3: Wikipedia, Electric Power Transmission A particular tower can have one set of 3-phase transmission lines (A, B, and C phases) on one side and another set on the other side, ultimately, delivering two sets of 3-phase transmission lines. Transmission towers can house multiple circuits or multiple conductors. These transmission conductors are not insulated and are comprised of several steel-aluminum alloy strands. Electricity is transmitted over transmission lines suspended in air on very tall transmission towers with large insulators in order to maintain proper electrical potential clearances from the ground, structures, or phases. Power can be transmitted across states, from one side of the country to the other, or across different countries. Electric power is transmitted at higher voltages to limit the power losses that can occur in long distance transmission lines. The blue color illustrates the transmission network to the substation and step-down transformer, and the green color shows the distribution network with three-phase or single-phase connections of AC power.įigure 2: Wikipedia, Electricity Grid Electric TransmissionĮlectric transmission plays the role of sending electricity over very long distances at very high voltage levels.
#ELECTRIC GRIDS GENERATOR#
Shown below in figure 2, taken from Wikipedia’s “Electricity Grid”, it illustrates the generating station in red along with a generator step-up (GSU) transformer which shows all three phases of AC power. After leaving the step-up transformer, the electricity is transmitted to power substations and ultimately distributed to end users. As the electricity leaves the generator, the voltage is stepped up with the use of step-up transformers located in what is known as generating stations or substations. The transmission and distribution (T&D) systems transport or deliver power for different purposes. The 3-phase power flow with phase angles at 120 degrees apart continues from generation to transmission to distribution and to the end power users.īoth electric transmission and distribution are used to deliver the generated electric energy or electric power from one place to another. Shown below in figure 1, taken from Wikipedia’s “Electricity Generator”, it illustrates a modern steam turbine generator housed in a generating power plant.įigure 1: Wikipedia, Electricity GeneratorĪs generators rotate with its separate coils, stators, and rotors, it produces 3-phase power via a magnetic field with each phase angle in the sinusoidal power flow curves for phases A, B, and C that are equally spread apart at 120 degrees. This flow of electrons travels on electrical conductors, such as, copper or aluminum. As the generators spin, they produce such a flow of electrons that they must have a place to go or require an outlet for the flow. In the US, generators turn at 60 revolutions per second or at 60 hertz (Hz). Power GenerationĮlectric power is generated as three phase alternating current (AC) by turning mechanical turbines from the forces of water, steam, or other means in order to turn generators, thereby, converting the mechanical energy into electric energy. If we look at the entire electric power system in three parts, electricity is: (1) generated at power plants, (2) transmitted over transmission lines, and then (3) distributed to the end users or customers. None of this would have been possible without the formation of electric power. Since the creation of electric power in the 1800s, major technology breakthroughs have evolved that have become necessities for the human race, like: light bulbs, telephones, stove-top ovens, refrigeration, heat ventilation and air conditioning (HVAC), hot water heaters, washers and dryers, TV’s, computers, security systems, internet, LED lighting, and so on…These new conveniences have greatly improved our standard quality of life, and they continue to progress. There is more to electricity than simply turning on a light switch. This is a basic explanation and summary of how the electric power grid works - by Matt Cole with 3 Phase Associates, LLC Electrical Energy