[GTALUG] mysterious restarts

[Stewart C. Russell]

James Knott wrote:
> 
> … There were a few different frequencies, other than 25 & 60 Hz.  There were
> even rotary converters …

I've seen rotary converters on very old off-grid systems for remote
power. Although somewhat inefficient, they output a true sine wave and
survive misuse far better than solid state ones do. If smoke comes out
of a solid state inverter, it's toast, but for a rotary, it's just its
way of telling you to back off a little.

If you're lucky enough to get a tour of the IESO's HQ, they have a relic
of the 25 Hz era on the wall. It's the display clock from the Shortt
Synchronome pendulum clock they used to use to regulate the grid.
Synchronomes are the most accurate mechanical clock ever made, and one
has even been used (briefly, ill-advisedly) as an NTP server.

%%%%%%%%%%%

Russell Reiter wrote:
>
> Had another power out at my building.

I think I was hit by that one this morning too, and I'm in the east end.

> … I kind of like the view down ft Roulle st and
> watching the windmill. I resist the temptation to attribute any of the
> electrical anomalies I have experienced to it's operations

As a director (again) of that project, I'm glad you like it, and I
appreciate that you're not blaming your outages on it. I'd be more
likely to attribute them to the Strachan substation, which is under
colossal pressure from all the new condo builds. The city is trying to
build a relief line and new substation capacity, but getting past
objections is tough.

The wind turbine has a rather nice AC (variable frequency)-DC-AC (60 Hz)
inverter. I imagine the new streetcars have something similar.

On DC, New York retired its last DC infrastructure only a few years ago.
The very last few DC customers now have rectifiers installed in their
basements, but are still charged the absurdly high DC metering price for
their power. I'm led to believe these are heritage buildings with
historic elevators and lighting which can't be replaced and remain
within code without tearing everything out.

cheers,
 Stewart