0
It carries a current at the set voltage of the line. Current is the actual electricity that flows along the line and is used up in your electric appliances whereas voltage is the difference between the energy being generated at the station and ground.
Answer
It carries both voltage and current. Voltage exists between each line conductor, and current flows through each line conductor.
Wiki User
∙ 9y ago
Wiki User
∙ 14y agoAs in any electrical circuit, a transmission system requires a power source. The power source is a generation plant that usually converts mechanical energy to electrical energy through mechanical shaft power that rotates an alternator. The alternator produces power in the form of alternating electrical voltage. The voltage is typically below 20,000 volts which is not high enough for most transmission systems. A transformer is connected to the generated output to increase the generated voltage to a much higher voltage, typically in excess of 100,000 volts, to be transmitted long distances. The transmission line distributes energy to substations, which have Transformers to reduce the voltage of the transmission line, down to much lower voltages, for distributing power to individual consumers.
Most all energy, transmitted in the U.S.. is transmitted with alternating electrical current, with voltages up to 640,000 volts. There are a few direct current lines that transmit at 1,000,000 volts however. To produce high voltage direct current, the voltage of the alternating current source is increased to 1,000,000 volts, and then it is converted to direct current. To be utilized at the opposite end of the line, the direct current is changed back to alternating current and it is tranformed to a lower voltage.
The higher transmission voltages, whether they be alternating current or direct current, allow the same energy to be transmitted, with proportionally less current (amperage) then at lower voltage, and therefore smaller, lighter wires and supporting structures can be used.
Add your answer:
Earn +20 pts
How do you convert kav to kilowatt?
By "kav", I'm assuming you mean "thousand-ampere-volts" ... usually represented as "KVA". Watts = (Volts) x (Amperes) x (power factor on the line) KW = KVA x (power factor on the line). The power factor on the line is the cosine of the phase difference between the voltage and current waveforms on the line.
What happens to voltage in a series circuit?
Total voltage = the source. The voltage around the circuit is divided proportionally by each of the resistances in line. The current is = the source voltage divided by the sum of all the resistance.
What is phase in electrical wiring?
The proper use of the term refers to the timing difference between voltages in a multi-phase power system. This makes more sense if you know that one complete AC cycle is divided up into 360 degrees, the same as a circle is. At 0 deg. the voltage is zero. At 90 deg. the voltage hits the positive peak. At 180 deg. the voltage falls back to zero. At 270 degrees the voltage falls to the negative peak. At 360 (same as zero) degrees, the voltage rises back up to zero, then the whole process repeats. In a 3-phase power system, each of the three hot conductors carry a voltage that is offset 120 degrees, or 1/3 of a cycle, from the next conductor. The voltage on each wire peaks at a slightly different time. However, in everyday use, the term phase has also come to mean which one of the three wires you want, as in "connect phase A to terminal 6", etc. It is even used in 240 volt (US) household power systems, where there are two different hot wires, even though it is technically not a multi-phase power system. So, if an electrician says phase, he most likely means one of the three hot wires in a 3-phase system.
When a line of clouds move across the sky this is an example of a?
convection current
How much ice will bring down power lines in an ice storm?
It takes as little as a quarter inch of ice to bring down a power line. Just one quarter of an inch can add 500 pounds of weight to the power line.
How much power can a transmission line carry example how much power can a 69kv line carry compared to a 390kv line what is the formula for power capacity of a hvac line?
For a line of given cross section and material, the power capacity will depend on the current carried, since resistance heating is proportional to (current)2 . For a given power, current is inversely proportional to voltage. Thus raising the voltage from 69 to 390 kv would reduce the current by a factor 69/390 = 0.177 , for the same power transmission, and reduce the heating losses by 0.1772 = 0.031. So you can see why high voltage for long distance lines is essential. Obviously the limiting current on a power line has to be set by economic and practical considerations, but if this is predetermined and set, the limiting power will be that which produces that limiting current, and power = voltage x current. The actual limiting curent will depend on the line cross section, material, and length. The power that a line of a certain voltage can carry is calculated by using the following formula: (2.55×(KV)2 /1000) MW.
What determines power?
Power = Current * Voltage * Power FactorAbove expression can further be explore as :1. For DC CircuitsPower = Current * Voltage2. For Single Phase AC CircuitPower = Current * Voltage * Power Factor3. For Three Phase AC CircuitPower = Line Current * Line Voltage * Power Factor
Need of ehv transmission lines?
Carry electrical power over extremely long distanceswith minimal I2*R losses. The higher the line voltage the lower the current the line has to carry to transmit the power from source to load.
What factors determine power?
Power = Current * Voltage * Power FactorAbove expression can further be explore as :1. For DC CircuitsPower = Current * Voltage2. For Single Phase AC CircuitPower = Current * Voltage * Power Factor3. For Three Phase AC CircuitPower = Line Current * Line Voltage * Power Factor
How in transmission line current decreases when voltage is increased?
Because power is power. If you maintain the same power, while increasing the voltage, you must decrease current. P=IE.
Which mode of transmission would result in less energy loss high current and low voltage or low current and high voltage Explain your reason?
low current high voltage power dissipation in power line = I2R the resistance of the power line is hard to reduce, especially when it is a long transmission line. but reducing the current through the line reduces losses as the square, a dramatic savings. reducing voltage would have no effect and would dramatically increase losses due to increase in current to try to deliver same power.
Can the amount of energy carried by a power line be increased by raising voltage?
Yes, by increasing the voltage in a power line, the amount of energy carried can be increased. This is because power (P) is the product of voltage (V) and current (I), and increasing the voltage while keeping the current constant will result in higher power carrying capacity. However, it is important to consider the limitations of the equipment and the safety considerations when increasing voltage levels.
Why During transmission of power it is transformed as high voltage rather than high current how is this possible as current and voltage are directly proportional?
Voltage and current are actually inversely proportional to one another. The formula P=IV is what you need to look at here, where P is Power, V is voltage, and I is current. Rearranging the equation you will see that V = P/I. You can see that if you increase voltage, while holding power constant, current is reduced. Now, to your question. The losses on a transmission line are proportional to the current flowing on the line, so transmitting at high voltage (and hence low current) is beneficial as it reduces the amount of power that is lost due to resistance in the line itself.
What is line voltage and line current in star connection define?
In star the voltage from line to neutral is 1/sqrt(3) times the nominal voltage, while the load current equals the line current. In delta the voltage between lines is the nominal voltage, while the load current is 1/sqrt(3) times the line current (for a balanced load). So a delta load needs 3 times the resistance compared to a star load of the same power.
How can a tuned RC circuit improve the power factor of an inductive motor circuit?
The RC circuit can reduce the phase shift between the voltage and current in the power line. The phase shift is caused by the inductance of the motor. The phase shift between the voltage and current in the power line causes problems due to the presence of so called imaginary current or power that does no work but must be supplied by the power source.
What voltage should be used when making three phase calculations?
With a three-phase system the voltage quoted is the line-to-line voltage between any two live lines. To find the line-to-neutral voltage divide by 1.732 which is sqrt(3). The power supplied from each phase is the current times the line-to-neutral voltage (times the power factor if less than 1). To find the total power when the currents are equal, multiply by 3.
Why is voltage increased in transmission?
Voltage is increased while transmission of power because it yield less losses due to the current carried by the line conductors.Losses = I*I*R, where I is current and R is resistance of lineHigher the voltage lower the current because the power remains the same.But, after certain limits you cannot increase the voltage further due to technical limitations like designing of transformers and the clearance between phase of transmission line and line to ground etc.AnswerFor any given load, the higher the supply voltage, the lower the resulting load current. This enables conductors with relatively small diameters to be used. Using low voltages would prohibit the use of reasonable-sized conductors. This it the primary reason for using high transmission voltages. Line losses, as described above, are a secondary reason.
