hal8000b wrote:
Let me save you a lot a trouble. The domestic ring main is not a high speed
data circuit. If you take data at 1Mbps then 1 data bit is just 1 micro
second duration.
...
I have mixed feelings about this.
First, it is a homework assignment. She cannot "save herself the trouble"
by telling the teacher that the assignment was wrong because the method is
inferior to running brand new copper or fiber. Sometimes it is impractical
to do that and you need to work with what you have.
Note that the signal range is 90-150 kHz, so it is not very high speed and
the symbol rate can't be anything close to 1Mbps. It also isn't the "BPL"
that floods the power lines with 2-50 MHz, used for Internet access, and a
major source of interference.
Power line communications have been used for close to a century, by the
power utilities themselves to monitor their own circuits without having to
run additional wires. The signaling rate might be as low as 1 to 10bps
(bps, not Mbps). I'm sure the power companies understand the difficulty of
carrying data signals in a noisy environment.
I am puzzled about the choice of a matrix representation for the lines. It
seems to me that gives you two major hurdles: how to generate the matrices
for typical power lines, and how to use it in a simulator. It would be one
thing if you were handed the matrices and instructed to use them. If
instead all you have is a physical description of the lines and topologies,
then SPICE's standard transmission line element might be the best choice.
Be aware that some things in SPICE work nicely in the frequency domain (.ac
analysis) but not the time domain (.tran analysis) or vice-versa.
(Transmission line models work correctly in both.)
Regards,
Andy
