PLC is one of my least preferred communications transports. Maybe
because it's a huge percentage of failures when charging, maybe because
there aren't that many vendors (for EVSE, it is dominated by a very
large chipmaker in San Diego).
Since this is going to be in an EV, I would prefer to use 100BaseT1, as
that is the current design win for EVs. Yeah, totally overkill as far
as bandwidth goes, but almost totally immune to noise - even without
shielding. CAN BUS requires some shielding, and has other limits.
BMS is used during three phases: charging, discharging, and storage
(keeping track of SoC, temperature, resistance). When the environment is
really noisy (think full power), you will REALLY need to make sure you
aren't draining your batteries too much.
Cheers, Peter
On 4/28/20 2:35 PM, Lawrence Winiarski via EV wrote:
Because there are no "mains" in a vehicle.???
Is it really "That" Noisy? I suspect it is very doable, it's just that no one
has done it yet.The trick is probably using signal processing to get rid of the noise and
doing extremelylow bit rates, which is fine for a BMS. Ham radio guys can send stuff
over the entire earthon 10 watts using techniques like jt65. I expect they can deal
with a little noise. it's justnot going to be trivial, but it would be doable.
IMHO the main use for the BMS is in charging anyway.
On Tuesday, April 28, 2020, 2:12:26 PM PDT, Lee Hart
<leeah...@earthlink.net> wrote:
Lawrence Winiarski wrote:
Anyone know anything about data over powerlines? Why can't the BMS
communicate over the mains?
Because there are no "mains" in a vehicle.
That said, it is possible to communicate via the DC power cables already
connected to each cell. But this is an extremely noisy environment. It
would require substantial filtering and protection to keep driving
currents from trashing data transfers. Some chargers are also extremely
noisy, and could block data transfers while charging.
Lee
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