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What is the condition for lossless transmission line?
Transmission Lines A lossless line has these properties: (a) it does not dissipate any power, (b) it is non-dispersive (i.e., the phase constant varies linearly with frequency ω, or the velocity vp = ω/β is independent of frequency), and (c) its characteristic impedance Z0 is real.
When a transmission line will called as lossless line?
Lossless line When the line is terminated with its characteristic impedance, the reflected portions of these equations are reduced to 0 and the solutions to the voltage and current along the transmission line are wholly incident.
What is lossy and lossless transmission lines?
A lossy transmission line consists of an appreciable value of series resistance and shunt conductance where different frequencies travel at different speeds. This is opposite to a lossless transmission line, where the speed of wave propagation is the same for all frequencies.
What is the value of SIL for transmission lines?
Hence, such an impedance which renders the line as infinite line is known as surge impedance.It has a value of about 400 ohms and phase angle varying from 0 to –15 degree for overhead lines and around 40 ohms for underground cables.
How to calculate the voltage of a lossless transmission line?
For a lossless transmission line, the voltage and current phasors can be calculated from equations 4.15 and 4.16 subject to α = 0 and are given by: (4.28) I ( z) = 1 Z 0 [ V 0 + e − j β z − V 0 − e j β z] = V 0 + e − j β z Z 0 [ 1 − Γ ( z)].
What is the reflection coefficient of a lossless transmission line?
The reflection coefficient for a lossless transmission line of characteristic impedance Z0, terminated with an impedance ZL, is given by: (1.20) Γ = Z − Z 0 Z + Z 0 = (Z / Z 0) − 1 (Z / Z 0) + 1 = z − 1 z + 1,
Is the attenuation constant for a lossless line real?
For the lossless line R = 0 = G; hence, the attenuation constant α = 0, and the characteristic impedance Z0 is real. In this case, these equations apply:
What is the surge impedance of a lossless line?
It is already explained that the characteristic impedance of a lossless line is called its surge impedance. The load that can be delivered by a lossless line is called SIL. For such a line power factor is taken as unity.