I am reading the very basics of the transmission lines circuits. I am asking this question to know more about the fundamentals and to reason out the basics.
I have two questions:
The basic circuit of a transmission line circuit consists of the elements that cause losses of the transmitted voltage and current. I always see: cable resistance, inductance and capacitance. Why do I see the inductance and resistance modeled as just series impedance (which makes things so smooth and easy in circuit analysis... just a voltage drop by an impedance) but the capacitor element is modeled as an admittance and not like them?
What I know is this:
Inductance is modeled as a XL = jωL in the frequency domain. Capacitance is modeled as Xc= -j/(ωC) in the frequency domain.
Mathematically, I can add up these two as one impedance but why do I see the transmission line circuits "insist" in putting the Xc as an admittance branch and not as series impedance? Why do they confuse us?
- Conventional thing?
- Physical reasoning behind it? See this question what is shunt charging in power systems? I mean just to show off that it is a capacitor between the line and ground?
- Mathematical Easiness? Y as an admittance is 1/Z. Okay? Would this cause the series Z to be flipped vertically in the circuit diagram? is this the reason?
As I was reading the basics, there is a Line to Line C and there is a Line to Neutral C. Are both of these two modeled in the circuit diagram in the same way..an admittance thing?