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What element(s) cause the phasor voltage to shift in a power system?

Why does the voltage phase angle increase with distance in a power grid?

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    \$\begingroup\$ Electricity doesn't travel infinitely fast so, at some distance down a cable, the voltage will be delayed by a small amount with the delay getting bigger as distance increases. A fixed delay = some amount of phase shift. \$\endgroup\$
    – Andy aka
    Sep 25, 2015 at 14:30
  • \$\begingroup\$ @Andyaka Thank you for your answer. But i think it has nothing to do with the speed of trevel (drift speed) of electricity. According to me one should be thinking about the voltage drop in inductive wires (i think that voltage drop (inductive) is causing the phase shift in voltage at preceeding node). For example: [V2,theta1] = [V1, theta1] - [V12, theta12] \$\endgroup\$ Sep 25, 2015 at 14:39
  • \$\begingroup\$ Open your mind. The inductance and capacitance form a transmission line and that transmission line means the velocity is somewhat less than speed of light at a value totally defined by the inductance per metre and the capacitance per metre. \$\endgroup\$
    – Andy aka
    Sep 25, 2015 at 14:43
  • \$\begingroup\$ ok.! So In the first comment you want to say that the speed of travel of electricity is not constant.? @Andyaka \$\endgroup\$ Sep 25, 2015 at 14:54
  • \$\begingroup\$ @AmritbirSinghGill No, the speed of the wave is constant in a given type of transmission line. In a transmission line with more capacitance and inductance, the wave will move slower. Note that the movement of electrons and movement of a wave are unrelated ! Compare sound through air, sound travels at 300 m/s but that does not mean the air is coming to you at 300 m/s. The air is just the medium. In a transmission line the electrons are the medium. \$\endgroup\$ Sep 25, 2015 at 15:17

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Electricity doesn't travel infinitely fast so, at some distance down a cable, the voltage will be delayed by a small amount with the delay getting bigger as distance increases. A fixed delay = some amount of phase shift.

I know this is for much higher frequencies but the dielecric material in a cable affects velocity of propagation of electricity at any frequency but, it's more noticable at higher frequencies in a lab using an oscilloscope: -

enter image description here

Basically it's telling you that the wavefront of a signal travels down a cable at speeds slower than the speed of light when the relative dielectic constant is greater than 1.

For a very long power cable you will see what appear to be phase shift along the cable but this is due to the velocity of propagation not being infinite. Here are the simple formulas that describe the speed of light and velocity of a wave down a cable: -

enter image description here

This is a useful site for learning.

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