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Why is impedance of a transmission line an important factor with respect to matching out of a transmitter into an antenna?
The impedance of a transmission line (Zo) should be matched from the source of the RF into the antenna. A bad match results in loss of output power and RF reflections up & down the transmission line. Standing Wave Ratio (SWR) meters are available to measure these reflections and enable them to be tuned out. Adjustment of antenna length for best SWR (1:1) is common. More mathmatical approaches are available on the web.
What is the difference between a transmission grid and an electricity grid?
The terms transmission grid and electrical grid are somewhat interchangeable. The electrical grid, or power grid, is the network used to get electric power from where it is generated to all the places that use it. The one difference might be that a transmission line or grid might be thought of as the network of high voltage long distance lines. These are used to move large amounts of power with minimal loss through the use of extremely high voltages. These long distance lines connect generation facilities with substations, and it is at the substation that the voltages are stepped down, and that power is then put on the electrical grid.
In order to reduce inductive reactance what devices are normally placed on transmission or distribution lines?
== == Add a capacitor or a synchronous motor or a phase advancer to the transmission line so that it can nullify the effect of inductive reactance since the above elements gives capacitive reactance. Doing this also improves the power factor.
Electric power is transferred over large distances at very high voltages Explain how the high voltage reduces power losses in transmission lines?
The conductor used to transmit power has a specific resistance at the given power frequency. Power transmitted is equivalent to I^2 * R, so as the current increases, the power loss from the conductor also increases. To maximize efficiency, power is converted to very high voltages, which decreases the current, which minimizes the power lost in transmission.AnswerThe primary reason for using high voltage transmission lines is because, for a given load, the higher the voltage, the lower the load current. Low voltages would require cables of enormous cross-sectional area making transmission impossible, whereas high voltages allow the use of manageable-sized conductors. A secondary reason is the corresponding reduction in line losses -as described above.
What is data cable?
Just as electric cable transmits electric line power from the transmission center to receiving station so the data cable in digital communication transmits the encoded binary digits from a digital transmission system to a digital receiving system.
How do you transmit ac power flow in HVDC transmission line?
You don't! That's the whole point of a d.c. transmission line.
What is Corona power loss in transmission line?
Corona Fields arround a transmission line is the high electric field caused by the transmission line causing the surrounding air to ionise and conduct electricity. As this ionisation requires a current to maintain, this causes a loss associated with the corona.
What are the Advantages of Corona in transmission lines?
Due to corona effect virtually conductor size is increase and therefor resistance in transmission line is decreases.so I2R losses will decreases...
Advantage and disadvantage of corona of transmission line?
advantages:due to corona formation the sir surrounding the conductor becomes the conducting and hence virtual dimeter of the conductor is increased.
Distinguish between HVDC and HVAC transmission?
DC versus AC.The vast majority of electric power transmissions use threephasealternating current. The reasons behind a choice ofHVDC instead of AC to transmit power in a specific caseare often numerous and complex. Each individualtransmission project will display its own set of reasonsjustifying the choice.A. General characteristicsThe most common arguments favouring HVDC are:1) Investment cost. A HVDC transmission line costsless than an AC line for the same transmissioncapacity. However, the terminal stations are moreexpensive in the HVDC case due to the fact thatthey must perform the conversion from AC to DCand vice versa. On the other hand, the costs oftransmission medium (overhead lines and cables),land acquisition/right-of-way costs are lower in theHVDC case. Moreover, the operation andmaintenance costs are lower in the HVDC case.Initial loss levels are higher in the HVDC system,but they do not vary with distance. In contrast, losslevels increase with distance in a high voltage ACsystemAbove a certain distance, the so called "break-evendistance", the HVDC alternative will always givethe lowest cost. The break-even-distance is muchsmaller for submarine cables (typically about 50km) than for an overhead line transmission. Thedistance depends on several factors, as transmissionmedium, different local aspects (permits, cost oflocal labour etc.) and an analysis must be made foreach individual case (Fig. 3).2) Long distance water crossing. In a long AC cabletransmission, the reactive power flow due to thelarge cable capacitance will limit the maximumtransmission distance. With HVDC there is no suchlimitation, why, for long cable links, HVDC is theonly viable technical alternative.3) Lower losses. An optimized HVDC transmission linehas lower losses than AC lines for the same powercapacity. The losses in the converter stations have ofcourse to be added, but since they are only about 0.6% of the transmitted power in each station, the totalHVDC transmission losses come out lower than theAC losses in practically all cases. HVDC cables alsohave lower losses than AC cables.4) Asynchronous connection. It is sometimes difficult orimpossible to connect two AC networks due tostability reasons. In such cases HVDC is the onlyway to make an exchange of power between the twonetworks possible. There are also HVDC linksbetween networks with different nominalfrequencies (50 and 60 Hz) in Japan and SouthAmerica.5) Controllability. One of the fundamental advantageswith HVDC is that it is very easy to control theactive power in the link6) Limit short circuit currents. A HVDC transmissiondoes not contribute to the short circuit current of theinterconnected AC system.7) Environment. Improved energy transmissionpossibilities contribute to a more efficient utilizationof existing power plants. The land coverage and theassociated right-of-way cost for a HVDC overheadtransmission line is not as high as for an AC line.This reduces the visual impact. It is also possible toincrease the power transmission capacity forexisting rights of way. There are, however, someenvironmental issues which must be considered forthe converter stations, such as: audible noise, visualimpact, electromagnetic compatibility and use ofground or sea return path in monopolar operation.In general, it can be said that a HVDC system ishighly compatible with any environment and can beintegrated into it without the need to compromise onany environmentally important issues of today.
Why does a 2003 impala transmission loses power?
TRANSMISSION LINE LOSSES
What is uncompensated power transmission line?
theriyathu
Performance of transmission line with respect to Nigeria power system?
performance of transsion line of nigeria power system
Describe the various methods of reducing corona effect in an overhead transmission line?
1. by increasing conductor size. 2. by increasing conductor spacing.
Which line requires compensation?
Basically an AC transmission line require compensation in terms of reactive power. To push the active power across a transmission line certain amount of reactive power is necessary. In AC transmission line reactive power is generated and consumed. Generator is responsible for the production of reactive and active power both. Than this reactive power is consumed by the load and transmission line. Additional reactive power s supplied by the capacitor. This extra power supplied by the capacitor is termed as reactive power compensation. Requirement of this reactive power is there because reactive power is necessary to maintain the voltage stability.
How many max transmission voltage in India?
There are three types of transmission lines of India given follows ---- 1-long transmission line( which is used grid to power suppliers plant ) 2-medium transmission line ( which is used power supplier plant to the industry ) 3- short transmission line ( which is used transformer to the consumers )
Which power transmission is best ac or dc?
yes, i think dc transmission is best, coz in dc losses is low, no iductance between conduct, less corona loss.AnswerNeither is 'better'; they each have advantages and disadvantages. For example, although there might be less losses with d.c. transmission, the equipment required to raise and reduce the voltage at each end of the line is more costly than for an a.c. transmission system.
