The biggest transmission substations can cover a vast area (several acres or hectares) and have numerous voltage levels, a significant number of circuit breakers, and a huge amount of protection and control equipment (voltage and current transformers, relays, and SCADA systems). They are usually built as an assembly of different modules that perform specific functions. The main components of a transmission substation include:
• Power transformers: These devices take high-voltage AC power from the utility company and reduce it to lower voltages required by the next stage of the distribution system. There are two types of power transformers used in transmission substations: medium voltage (1,000 volts or more) and low voltage (300 to 1,000 volts). Medium voltage power transformers typically weigh about 100 pounds (45 kg), while low voltage ones range in size from a few pounds to almost 200 pounds (90 kg or more).
• Current transformers: These devices measure the magnitude of current flowing through wires delivering power to consumers. The current measured by a current transformer is proportional to the primary current carried on the conductor supplying power with a coefficient determined by the material composition of the core. For example, if the current in the conductor is 400 amperes, the secondary current would be 400 amps too. Current transformers are used for measuring electric power delivered to customers over various points in a distribution network for purposes such as metering and testing.
Considerable transmission substations can occupy a significant area (several acres or hectares) and contain various voltage levels, a huge number of circuit breakers, and a large quantity of protection and control equipment. A distribution substation is a facility that distributes power from the transmission system to an area's distribution system. Distribution substations are usually located in urban areas and act as a buffer between the high-voltage transmission lines and the low-voltage wiring that feeds into houses and businesses.
The term "substation" also refers to the building housing those functions. The words "transmission" and "distribution" should not be confused; a transmission substation converts high voltage from transmission lines to lower voltages for delivery to end users. A distribution substation delivers power at lower voltage from the transmission line to local offices, houses, and businesses.
Substations must be robust structures designed to protect people from electrical shocks and other hazards of electricity. They include switching stations that open and close circuits through which current passes, and transformer stations that step down high voltage from transmission lines to lower levels for distribution within cities.
A transmission substation may have two main functions: to change the voltage of transmissions coming off the transmission line down to the voltage level required by distributors/substations; and to distribute this lowered voltage to these same distributors/substations. A distribution substation only changes the voltage of transmissions and does not itself generate any power.
A typical power plant substation. To decrease line losses, typical long-distance transmission voltages vary from 155,000 to 765,000 volts. The greatest transmission distance is typically around 300 miles (483 km). When you see high-voltage transmission lines, they are fairly evident. These are usually aluminum because they're so much lighter than steel.
The voltage on a transmission line drops as it goes farther away from the substation. The further away, the faster the voltage decreases. At very large distances, the voltage becomes so low that it can't be used by normal household equipment. This is called "distribution voltage" and it's kept at a safe level for humans and animals by bringing in more power from another location to fill in the gap. For example, if there's not enough voltage being generated at a power station to supply all of its customers, then generators will switch on to make up the difference. This is called "load shedding" and it's an important factor in determining how far a transmission line can be stretched without causing unnecessary energy loss.
The distribution voltage needs to be lower when there's a large load on the system than when there's not. This is because there's less voltage available for everyone else when some people are getting too much electricity. Since household appliances use current rather than just voltage, this also means that their maximum amperage increases when there's a lot of demand on the system.
Substations are part of the power distribution network, and their sizes vary depending on whether they are designed to service residences or industries. It is not dangerous in and of itself because it is a substation, but it will be surrounded by an electromagnetic field. If you are have any metal in your body, such as iron in your blood, it will be attracted to the magnetic field and could be injured by it.
The danger from small substations comes from the fact that they can produce large amounts of electricity from small wires- usually less than 3 feet apart. These small wires are called feeders and they connect to houses or businesses along with other feeders to make up the whole grid. If one of these feeders gets damaged or falls into disrepair, it can cause all the other feeders along with those parts of the system that it connects to - including the small substation- to malfunction. This can result in things like lights going out or equipment breaking down without warning. The best way to protect yourself from harm is not to have metal in your body when you go inside the field generated by a small substation.
Large substations are also used in power grids to distribute electricity over long distances. They are usually found near large cities or industrial areas. Like small substations, large ones can cause injury if they malfunction because of the energy they can generate.
A substation's aim is to'step down' high voltage power from the transmission system to lower voltage electricity, which may then be conveniently provided to homes and businesses in the region through lower voltage distribution lines. High expansion in certain locations necessitates the demand for more power. The solution is to build a new power station to supply this increased demand. However, building these large power stations is expensive and time-consuming. Thus, the industry developed an alternative: the substation.
The first power substations were built in the early 20th century to step down high voltages from lightening rods on tall towers into lower voltages suitable for use in homes. As technology improved, so did the requirements of power engineers. By the 1950s, power companies began installing sub-substations- smaller substations within substations- to reduce costs and increase efficiency. Today, power companies need substations to distribute power from remote generators onto the grid, provide backup power during emergency situations, and isolate faulty equipment.
Substations play an important role in our daily lives. They allow us to use electricity safely and efficiently, while also allowing power companies to maintain their infrastructure. Substations are vital to our economy and community; without them, there would be no power available at all. It is therefore necessary to maintain and upgrade substations regularly so that they can continue to provide service to our society.
A substation is an essential component of a power transmission system that includes transformers (and other power system components). 1. Substation transformers are categorised into several (potentially disjoint) categories based on their voltage levels (power levels), role in a power grid, insulation class, or construction, among other factors. 2. All transformer types have a maximum rating of voltage across any single conductor or pair of conductors. If this limit is exceeded, the transformer will fail in some way, usually due to damage caused by overloading. The most common cause of failure is flashover - the release of energy in the form of a sudden high current flow which heats up the metal parts of the transformer and can lead to burning or melting of them. However, a transformer can also fail due to excessive magnetic flux density, self-induced vibration, or corrosion of internal iron parts.
3. A substation transformer must be located near enough to other power lines so that the total load on all lines is less than their maximum ratings. Otherwise, one line would exceed its limit and break down. 4. Transformer design requires balancing the primary and secondary currents to prevent overheating and other failures. This is done by including more or fewer windings on one side of the core than the other. 5. Substations also include switchgear such as circuit breakers, reclosers, and meter stations for electricity distribution and consumption monitoring. These devices use mechanical and electrical components to open and close power circuits for maintenance or repairs.