Previously, power plants could only serve their immediate surroundings. Between the time it was made, and when it was used, electricity didn’t have to travel far. Things have evolved since then, and most of us now get our electricity from the grid, a vast network of power providers and consumers.
The need to efficiently transfer electricity over long distances has become more critical as power facilities have grown larger and further distant from inhabited areas. Connecting cities to power plants by stringing power lines over the terrain may appear simple as plugging an extension cord into an outlet. Nonetheless, the architecture behind these electric superhighways is far more complex and fascinating than you might imagine.
Electricity generation is a massive undertaking, sometimes including a complicated industrial process requiring large capital inputs and continuing operating, maintenance, and fuel costs. Electric utilities only get paid for the electricity that gets to your meter. They don’t get paid for the energy they waste on the grid. So, if we’re going to the trouble of creating electricity, we’d better make sure that as much of it as possible reaches the targeted users.
The issue is that most power plants are positioned far away from inhabited areas for various reasons: the land is cheaper in rural areas, many plants require extensive cooling ponds, and most people dislike living near large industrial sites. As a result, huge volumes of electricity must be carried considerable distances from generation to the point of usage.
What Is Electric Power Transmission?
Delivering generated electricity is known as electric power transmission or electrical transmission. This is frequently accomplished over vast distances to inhabited areas’ distribution grids. The mass transportation of electrical energy from a generating facility, such as a power plant, to an electrical substation, is known as electric power transmission. The system’s interconnected lines make it easier to move electrical power around. Transmission networks are what they’re called.
As explained earlier, the generating stations are not necessarily situated where most of the power is consumed. This is to say; distance is not the only factor determining the ideal location for a generating station; the power generated must be quite far from where it is used.
This is because land located further away from the load center, typically a high-density core area, will be substantially less expensive per square meter. Another cause is the proximity of a noisy and polluting station to residential areas.
Finally, electrical supply systems are the network that allows consumers to receive electricity from a generator. A thermal power station is what this is called.
Components of Electrical Power Transmission
The components of electrical power transmission are listed below.
Short transmission lines, medium transmission lines, long transmission lines, and long transmission lines are all part of the power transmission system. They all transmit electricity from a power source to a distribution system. This distribution system is responsible for supplying electricity to specific customer locations.
Power plants, distribution systems, and substations make up an electrical transmission system. An electrical grid is made up of all of these components. This grid meets the electricity requirements of civilization.
Transmission lines or power lines carry electricity from one location to another. The electricity is commonly alternating current so that step-up transformers can boost the voltage, allowing for effective transmission for distances of up to 500 kilometers. The following are the three sorts of lines:
The voltage range on these transmission lines is extremely high, ranging from 100 kV to 800 kV. They’re designed for long-distance transmission and require a high voltage to avoid power losses due to resistance.
Underground lines transport power across densely populated areas, underwater, and other locations where overhead lines are not possible. Because of the greater and heat-related losses, they are less prevalent than overhead lines.
Lower voltages, ranging from 26 kV to 69 kV, are transported to distribution stations via these transmission lines. This transmission might take place either above ground or underneath it.
Element of a Transmission Line
- Conductors: a transmission line conductor must be of proper size (i.e., cross-sectional area), depending on its current capacity—three for a single circuit line and six for a double circuit line. The most common variety is aluminum-core steel-reinforced conductors.
- Protective devices: Ground wires, lightning, relays, arrestors, circuit breakers, and other components help protect the power transmission system and assure its reliability. Finally, ground wires, lightning, relays, arrestors, circuit breakers, etc., help protect the power transmission system and ensure reliable operation. Finally,Voltage regulators assist keep the voltage at the receiving end within acceptable limits.
- Transformers: step-up transformers are used to step up the voltage level, and step-down transformers are used to step it down.
- Line insulators. Because they are electrically insulated from the support towers, the line insulators mechanically support the line conductors.
Support towers: This keeps the line wires dangling in the air in place.
Types of Electrical Power Transmission
Below are the major types of transmission systems:
The electrical energy generated at a power plant is normally between 11kV and 33kV in voltage. It is stepped up with a transformer before being transferred to distribution centers via transmission lines to a voltage level that can range from 100kV to 700kV or more, depending on the distance it must be transmitted; the longer the distance, the higher the voltage level.
When electrical power is transmitted, it is stepped up to these voltage levels to improve efficiency by reducing I2R losses. When the voltage is stepped higher, the current decreases to the voltage, keeping the power constant and lowering I2R losses.
The transfer of a substantial amount of electrical power from the primary generating station to the substation through overhead electrical lines is known as direct transmission at this point. Underground cables are also employed in some nations when transmission takes place over a lesser distance.
When electrical power reaches a receiving station, the voltage is normally reduced to 33kV or 66kV. It is then transferred to electrical substations closer to “load centers,” such as cities, towns, and metropolitan regions, via transmission lines that emerge from this receiving station. Secondary transmission is the term for this technique.
When electrical power arrives at a substation, it is stepped down by a step-down transformer to voltages closer to those at which it was generated—usually around 11kV. The transmission phase then transitions to the distribution phase, where electrical power meets primary and secondary consumer demand.
While electricity can be transported underground occasionally, most “bulk” transmission systems use overhead wires. Why massive steel towers are needed is a recurring issue addressed concerning overhead wires, especially during planning. The two most important responses are safety and dependability.
Because of the high voltages involved, local, state, and federal authorities restrict how transmission lines can be constructed, mostly for safety reasons. One of the most important requirements is how high the wires must be off the ground at their lowest point (“clearance”). Clearance requirements vary significantly but typically range from 60 to 150 feet.
Along with the need for height, there is also a need for stability. Transmission lines and towers must survive a variety of environmental factors, including severe winds and cold temperatures, when ice and snow deposits could cause a line or tower to collapse. As a result, high-voltage towers are often built to withstand so-called 50- or 100-year storms to prevent power outages.
Different Types of Electrical Power Transmission System
AC and DC Power Transmission
Electrical energy can be transmitted in alternating current (AC) and direct current (DC). ‘High voltage DC electrical transmission system and high AC electrical transmission system,’ they’re termed. These two energy transmission systems each have their benefits and drawbacks detailed below.
Advantages of Using DC Transmission System
The following are some of the drawbacks of the DC transmission system:
- For a DC transmission system, only two conductors are necessary. When the earth serves as the system’s return path, it is even possible to use only one conductor in a DC transmission system.
- Inductance, capacitance, phase displacement and surge problems can all be solved with a DC system.
- Because the potential stress on the insulator of a DC transmission system is around 70% that of an equivalent voltage AC transmission system, DC transmission systems offer lower insulation costs.
Advantages of AC Transmission System
The following are some of the benefits of using an AC transmission system:
- Alternating voltages can be easily ramped up and down, whereas DC transmission types cannot.
- Converting electricity in an AC electrical substation is easier than in a DC system with motor-generator sets.
- Compared to DC, maintaining an AC substation is far easier and less expensive.
Disadvantages of AC Transmission System
Despite the good benefits of the AC transmission system, some limitation still occurs. Below are the disadvantages of AC power transmission:
- When compared to DC systems, AC systems require a larger conductor volume.
- The line’s reactance frequently influences the voltage regulation of the electrical power transmission system.
- Corona discharge is more likely to disrupt these transmission systems than a DC power transmission system.
- Before connecting multiple transmission lines, an AC system must be properly synchronized. On the other hand, Synchronization can be overlooked in DC power transfer types.
- An air conditioner can cause skin and proximity impacts.
- The construction of an AC electrical power transmission network is far more advanced than a DC system.
Today, electrical power transmission is critical because it is one of humanity’s most fundamental needs. The method of delivering electrical power to end customers is known as electrical power transmission. As promised, this article covered the definition of electrical power transmission and its components, elements, types, and workings, as well as factors to consider while constructing a power generating station. This post should have provided you with a lot of useful information.
Lastly, for any power transmission components, contact us at ICRFQ and place your order. At ICRFQ we are the best electrical components manufacturers in China.
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