powerline modem over dc line

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Hi, has someone any kind of experience or information about
implementing a communication over a dc power bus. In particular that
dc bus is the output (700V) of various step-up machines that are in
parallel elevating the voltage of independent photovoltaic strings in
order to be the input of a three-phase inverter to be the power
injected in a low-voltage three-phase distribution power line. The
frequency of the switching of the machines is arround 15KHz.

The first idea is the use of comercial PL modems like ST7540. But I
has the impression that perhaps this would be not correct at all,
because these are implemented in order be used in a residencial
powerline with the type of transmision caracteristics of them
(attenuation,...), with the types of loads characteristics in that
nets, and with the type of noise superimposed also. In consecuence the
frequency of the carrier, characteristic of the transmisor driver, and
receiver filters and perhaps the type of modulation are adecuated to
this (typically FSK or BPSK instead of spread spectrum for example),
but not to my case.

What do you opinion about this?

 

[Charlie Edmondson]

Hi, has someone any kind of experience or information about
implementing a communication over a dc power bus. In particular that
dc bus is the output (700V) of various step-up machines that are in
parallel elevating the voltage of independent photovoltaic strings in
order to be the input of a three-phase inverter to be the power
injected in a low-voltage three-phase distribution power line. The
frequency of the switching of the machines is arround 15KHz.

The first idea is the use of comercial PL modems like ST7540. But I
has the impression that perhaps this would be not correct at all,
because these are implemented in order be used in a residencial
powerline with the type of transmision caracteristics of them
(attenuation,...), with the types of loads characteristics in that
nets, and with the type of noise superimposed also. In consecuence the
frequency of the carrier, characteristic of the transmisor driver, and
receiver filters and perhaps the type of modulation are adecuated to
this (typically FSK or BPSK instead of spread spectrum for example),
but not to my case.

What do you opinion about this?

It is probably not a good idea.

Typically, on a DC bus, you are trying to avoid noise. You usually have
capacitors and other filters to try and eliminate noise as much as
possible. Most powerline data transmission is on an AC bus, where such
noise is a little (not much) more acceptable.

If you need to monitor and control solar panels, just run some CAT5 out
to them, and do yourself a huge favor...

Charlie

 

[kfet]

regulate a RGB Led driver through a DC powerbus

Hey, I want to do something like you.
I want to regulate a RGB Led driver through a DC powerbus.
I would use a ST7540 (because I have one).
I've been looking on the net but didn't found much to get me going.