Electric power transmission is one process in the transmitting of electricity to consumers. The term refers to the bulk transfer of electrical power from place to place.
How Electrical Power can transmission?
Typically, power transmission is between the power plantand a substationnear a populated area.This is distinct from electricity distribution, which is concerned with the delivery from the substation to the consumers. Due to the large amount of power involved, transmission normally takes place at high voltage (11kV or above).
Electricity is usually transmitted over long distance through overhead power transmission lines. Underground power transmission is used only in densely populated areas (such as large cities) because of the high cost of installation and maintenance.
A power transmission system is sometimes referred to colloquially as a “grid”; however, for reasons of economy, the network is rarely a true grid. reduandant paths and lines are provided so that power can be routed from any power plant to any load center, through a variety of routes, based on the economics of the transmission path and the cost of power.
Voltage of Electrical Power transmission
Transmission-level voltages are usually considered to be 11 kV and above. Lower voltages such as 66 kV and 33 kV are usually considered sub-transmission voltages but are occasionally used on long lines with light loads. Voltages less than 33 kV are usually used for distribution.
Electrical power trnasmiision through long electrical line. Generally voltage of electrical transmission line is 66kV,132kV,220kV,400kV,765kV. Based on electrical power transmission voltage, intermediate electrical substation require for electrical power transmission.
Voltages above 230 kV are considered extra high voltage and require different designs compared to equipment used at lower voltages. Overhead transmission lines are not insulated, so design of these lines requires minimum clearances to be observed to maintain safety.
Electrical Power transmission network
Engineers design transmission networks to transport the energy as efficiently as feasible, while at the same time taking into account economic factors, network safety and redundancy. These networks use components such as power lines, cables, circuit breakers, switches and transformers.
Efficiency is improved by increasing the transmission voltage using a step-up transformer, which has the effect of reducing the current in the conductors, whilst keeping the power transmitted nearly equal to the power input. The reduced current flowing through the conductor reduces the losses in the conductor and since, according to Ohms Law, the losses are proportional to the square of the current, halving the current results in a four-fold decrease in transmission losses.
A transmission grid is a network of power station, transmission circuits, and substations. Energy is usually transmitted within the grid with three-phase AC. DC systems suffer from the fact that voltage conversion is expensive (and so are only used for special high voltage links) while single phase AC links suffer from oscilation in the power.
High Voltage DC(HVDC) Electrical power transmission
High voltage DC (HVDC) is used to transmit large amounts of power over long distances or for interconnections between asynchronous grids. When electrical energy is required to be transmitted over very long distances, it can be more economical to transmit using direct current instead of alternating current.
For a long transmission line, the value of the smaller losses, and reduced construction cost of a DC line, can offset the additional cost of converter stations at each end of the line.
Also, at high AC voltages significant amounts of energy are lost due to corona discharge, the capacitance between phases or, in the case of buried cables, between phases and the soil or water in which the cable is buried.
Since the power flow through an HVDC link is directly controllable, HVDC links are sometimes used within a grid to stabilize the grid against control problems with the AC energy flow.
Pingback: IoT(Internet of Things) in Electrical Power Grid - Electricalsphere
Pingback: Understand Wireless Laser Power Transmission and it’s Application
Pingback: Smart grid in Electrical power system - Electricalsphere
Pingback: Over current protective schemes in Power Transmission/Distribution system
Pingback: What is Directional or reverse power relay and their working and application
Pingback: Earth fault Relay protection in Power Transmission Line - Electricalsphere
Pingback: Different types of Protection on Transmission line
Pingback: Case studies on Transmission Line fault due to Bird
Pingback: What is Reactive Power and Reactive Power compensation,it's calculation
Pingback: HVDC Transmission: Types of HVDC link and components - Electricalsphere
Pingback: What is Flexible Alternating Current Transmission and FACT device
Pingback: Types of Faults and analysis in Power system