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Illustration of the Ferranti effect; addition of voltages across the line inductance. In electrical engineering, the Ferranti effect is the increase in voltage occurring at the receiving end of a very long (> 200 km) AC electric power transmission line, relative to the voltage at the sending end, when the load is very small, or no load is connected.
Multiple empirical formulae exist that relate the loss factor to the load factor (Dickert et al. in 2009 listed nine [5]). Similarly, the ratio between the average and the peak current is called form coefficient k [ 6 ] or peak responsibility factor k , [ 7 ] its typical value is between 0.2 to 0.8 for distribution networks and 0.8 to 0.95 for ...
Equivalent circuit of an unbalanced transmission line (such as coaxial cable) where: 2/Z o is the trans-admittance of VCCS (Voltage Controlled Current Source), x is the length of transmission line, Z(s) ≡ Z o (s) is the characteristic impedance, T(s) is the propagation function, γ(s) is the propagation "constant", s ≡ j ω, and j 2 ≡ −1.
The resistance and conductance contribute to the loss in a transmission line. The total loss of power in a transmission line is often specified in decibels per metre (dB/m), and usually depends on the frequency of the signal. The manufacturer often supplies a chart showing the loss in dB/m at a range of frequencies.
A typical loss for 800 kV lines is 2.6% over 800 km (500 mi). [53] Increasing the transmission voltage on such lines reduces the power loss, but until recently, the interconnectors required to bridge the segments were prohibitively expensive. However, with advances in manufacturing, it is becoming more and more feasible to build UHVDC lines.
Versions of the transmission-line equation may be similarly derived for the admittance loss free case and for the impedance and admittance lossy cases. The Smith chart graphical equivalent of using the transmission-line equation is to normalise Z L , {\displaystyle \,Z_{\mathsf {L}}\,,} to plot the resulting point on a Z Smith chart and to draw ...
When a transmission line is mismatched (SWR > 1:1), its input impedance deviates from its characteristic impedance; thus, a bridge can be used to determine the presence or absence of a low SWR. To test for a match, the reference impedance of the bridge is set to the expected load impedance (for example, 50 Ohms), and the transmission line ...
Mismatch loss in transmission line theory is the amount of power expressed in decibels that will not be available on the output due to impedance mismatches and signal reflections. A transmission line that is properly terminated, that is, terminated with the same impedance as that of the characteristic impedance of the transmission line, will ...