How much power runs through power lines?

How much power runs through power lines?

The voltage of a local transmission line is 13,800 volts. This voltage is then lowered even further to between 220 and 440 volts for industrial use and from 120 to 240 volts for commercial and residential customers.

How much power can a transmission line carry?

Transmission line voltages vary from 44,000 to over 765,000 volts. The higher the voltage, the more electricity the line can carry.

What is the difference between 11kV and 33kV transmission line?

The 11kV lines are used in residential areas and is what feeds the local transformers, which then distributes power to the buildings in the area. 33kV lines on the other hand involve much higher voltages and are used to distribute power from one small sub-station to another.

How do you calculate the power capacity of a transmission line?

Power Transmited

1. At 132 kv. Power in MW = Ö 3 132 x I x 0.8 / 1000. = 0.1828992 x I. = 0.183 x I.
2. At 220 kv. Power in MW = Ö 3 220 x I x 0.8 / 1000. = 0.305 x I.
3. At 400 kv. Power in MW = Ö 3 400 x I x 0.8 / 1000. = 0.554 x I.

What are the factors that limits the power capacity of the line?

Some of the factors which limits the maximum power transfer are: Electrical phase shift. Voltage drop. Thermal effects in the line.

How is VSWR calculated?

The VSWR definition states that the VSWR is equal to the maximum voltage on the line divided by the minimum voltage. The voltage fluctuations come about as a result of the voltage components from the forward power and the reflected power summing together.

What is a good VSWR reading?

A VSWR of less than 1.5:1 is ideal, a VSWR of 2:1 is considered to be marginally acceptable in low power applications where power loss is more critical, although a VSWR as high as 6:1 may still be usable with the right equipment.

Can VSWR be negative?

Summary. It is possible to have ρ>1. VSWR calculated from ρ is singular where ρ=1, and will yield negative VSWR where ρ>1. It may be unwise to ‘correct’ the VSWR(ρ) formula to give positive results as there is no longer the simple inverse function ρ=(VSWR-1)/(VSWR+1).

Why VSWR is measured?

VSWR (Voltage Standing Wave Ratio), is a measure of how efficiently radio-frequency power is transmitted from a power source, through a transmission line, into a load (for example, from a power amplifier through a transmission line, to an antenna). VSWR measures these voltage variances.

What is a bad SWR?

You might have a bad SWR meter, something wrong with your antenna or antenna connection, or possible have a damaged or defective radio. If the SWR reading on channel 1 is higher than the reading on channel 40, your antenna system is too short and you need to lengthen your antenna.

What are the types of VSWR meter?

In some ways it is possible to consider that there are two forms of VSWR measurement dependent upon how they are implemented, the test instrument, and the way in which the measurements are made. VSWR measurements using power from transmitter: These measurements are made using the power supplied by a transmitter.

How do you reduce VSWR?

One technique to reduce the reflected signal from the input or output of any device is to place an attenuator before or after the device. The attenuator reduces the reflected signal two times the value of the attenuation, while the transmitted signal receives the nominal attenuation value.

What can cause high VSWR?

High VSWR is often due to testing with very broadband, high-power, and poorly matched loads. It is best to avoid this situation as much as possible, however, sometimes this condition is unavoidable as testing must still be done. Below is a chart showing VSWR vs. reflected power.

How do I fix high SWR?

When you are experiencing a high SWR reading on one end of the frequency range, it is easy to adjust (lengthen or shorten) your antenna system to correct the problem.

Why return loss should be less than 10 dB?

Advanced Member level 4. The return loss measures the reflected wave to the incident wave, that is RL = -20 log(Γ). So, a return loss of -10 dB means that the reflected wave is 10 dB lower than the incident wave. This is approximately equal to a reflection coefficient of 0.3, so 30% of the incident wave is wasted.

What is S11 formula?

S11 = b1/a1 for a2= 0 or Zl=Zo. This is an input reflection coefficient. S11 is equal to the ratio of a reflected wave and an incident wave with Zl=Zo. Thus, S11 can be plotted on a Smith chart and the input impedance of the two-port device can be found immediately.

What is return loss dB?

When a signal is transmitted through a transmission line, some signal power is always reflected or returned to the source due to discontinuities in the transmission line. Return loss (RL) is the ratio of the reflected power to the incident power, in decibels (dB).

What is S11 S12 S21 S22?

S11 is the input port voltage reflection coefficient. S12 is the reverse voltage gain. S21 is the forward voltage gain. S22 is the output port voltage reflection coefficient. The S-parameter matrix can be used to determine reflection coefficients and transmission gains from both sides of a two port network.

What does S12 0 indicate?

2021 ICD-10-CM Diagnosis Code S12. 0: Fracture of first cervical vertebra.

What is S11 parameter in antenna?

In practice, the most commonly quoted parameter in regards to antennas is S11. S11 represents how much power is reflected from the antenna, and hence is known as the reflection coefficient (sometimes written as gamma: or return loss. If S11=0 dB, then all the power is reflected from the antenna and nothing is radiated.