[GTALUG] mysterious restarts

[Lennart Sorensen]

On Tue, Jun 14, 2016 at 03:15:07PM -0400, Alvin Starr via talk wrote:
> It is possible.
> Not saying its so, but if the new cars can handle variable voltage and the
> old cars are fixed voltage then it could make sense to upgrade the lines in
> advance of removing all the old cars.
> Then when all the old cars are gone upgrade the system voltage.
> 
> Its not that you would need to put in heaver lines for higher voltage but a
> close to 50% increase in voltage may make you replace all the insulators
> that were rated for 600V with ones rates for 750V.
> 
> I would expect the motors on the new cars would be based on AC motors which
> is the predominant motor type in electric automobiles but with something as
> big as a train the rules for motor choice may be different.
> With AC motors the control electronics would have to handle the voltage
> variations but its doable.

Well certainly electric cars and hybrids all use AC motors with DC
storage and generate the desired AC.  I would be surprised if the new
streetcars don't do the same.

So given that, it is quite possible that they may in fact be able to
handle a range of voltages.  Of course since they probably need a bit of
onboard battery capacity, that could be a bit more complicated depending
on how they choose to deal with the incoming DC power.

-- 
Len Sorensen