My Grid System
An electrical grid is an interconnected network for delivering electricity from producers to consumers. It consists of generating stations that produce electrical power, high voltage transmission lines that carry power from distant sources to demand centers, and distribution lines that connect individual customers.
Power stations may be located near a fuel source, at a dam site, or to take advantage of renewable energy sources, and are often located away from heavily populated areas. They are usually quite large to take advantage of economies of scale. The electric power which is generated is stepped up to a higher voltage at which it connects to the electric power transmission network.
The bulk power transmission network will move the power long distances, sometimes across international boundaries, until it reaches its wholesale customer (usually the company that owns the local electric power distribution network).
On arrival at a substation, the power will be stepped down from a transmission level voltage to a distribution level voltage. As it exits the substation, it enters the distribution wiring. Finally, upon arrival at the service location, the power is stepped down again from the distribution voltage to the required service voltage(s).
Electrical grids vary in size from covering a single building through national grids which cover whole countries, to transnational grids which can cross continents
Early electric energy was produced near the device or service requiring
that energy. In the 1880s, electricity competed with steam, hydraulics, and
especially coal gas. Coal gas was
first produced on customer’s premises but later evolved into gasification plants that
enjoyed economies
of scale. In the industrialized world, cities had networks of piped
gas, used for lighting. But gas lamps produced poor light, wasted heat, made
rooms hot and smoky, and gave off hydrogen and carbon monoxide. In the
1880s electric lighting soon became advantageous compared to gas lighting.
Features
Voltage
Grids are designed to supply voltages at largely constant amplitudes. This has to be achieved with varying demand, variable reactive loads, and even nonlinear loads, with electricity provided by generators and distribution and transmission equipment that are not perfectly reliable.
Frequency
An entire grid runs at the same frequency. Where interconnection to a neighboring grid, operating at a different frequency, is required, a frequency converter is required. High voltage direct current links can connect two grids that operate at different frequencies or that are not maintaining synchronism.
In a synchronous grid all the generators must run at the same frequency, and must stay very nearly in phase with each other and the grid. For rotating generators, a local governor regulates the driving torque, maintaining constant speed as loading changes. Droop speed control ensures that multiple parallel generators share load changes in proportion to their rating. Generation and consumption must be balanced across the entire grid, because energy is consumed as it is produced. Energy is stored in the immediate short term by the rotational kinetic energy of the generators.
Small deviations from the nominal system frequency are very important in regulating individual generators and assessing the equilibrium of the grid as a whole. When the grid is heavily loaded, the frequency slows, and governors adjust their generators so that more power is output (droop speed control). When the grid is lightly loaded the grid frequency runs above the nominal frequency, and this is taken as an indication by Automatic Generation Control systems across the network that generators should reduce their output.
In addition, there's often central control, which can change the parameters of the AGC systems over timescales of a minute or longer to further adjust the regional network flows and the operating frequency of the grid. For timekeeping purposes, over the course of a day the nominal frequency will be allowed to vary so as to balance out momentary deviations and to prevent line-operated clocks from gaining or losing significant time.
Off-the-grid is a system and lifestyle designed to help people function without the support of remote infrastructure, such as an electrical grid. In electricity, off-grid can be stand-alone power system or mini-grids typically to provide a smaller community with electricity.
Off-grid electrification is an approach to access electricity used in countries and areas with little access to electricity, due to scattered or distant population. The term off-the-grid (OTG) can refer to living in a self-sufficient manner without reliance on one or more public utilities. People who adopt this lifestyle are called off-gridders.
Off-the-grid homes are autonomous; they do not rely on municipal water supply, sewer, natural gas, electrical power grid, or similar utility services. A true off-grid house is able to operate completely independently of all traditional public utility services.
The National Grid (India) is the
high-voltage electric power transmission network
in mainland India, connecting power stations and major substations
and ensuring that electricity generated anywhere in mainland India can be used
to satisfy demand elsewhere.The National Grid
is owned, operated, and maintained by state-owned
Power Grid Corporation of India. It is one of the largest
operational synchronous grids in the world with 329.23 GW of installed power
generation capacity as on 30 June 2017.
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