[GTALUG] Dirty Power and Wi Fi Far field effect

[Lennart Sorensen]

On Sat, Mar 14, 2015 at 06:57:49AM -0400, Russell Reiter wrote:
> What do you mean by completely split? Split as in; now separate grids or
> split by isolation terminals, firewalls if you will.

Some very big interconnects disconnected due to overloading.  This left
the grid in three isolated parts, one with over supply, one with under
supply and one that was pretty well balanced on its own.

It was all triggered by a misconfigured main link where one end had
different limits configured than the other end, so one end thought
shutting down a parallel line would be fine, but the other end tripped
due to misconfigured limits for the line, which then dropped all the
load on yet other lines, which then tripped, and bye bye grid.
Fortunately it only took about 45 minutes to restore everything.

> Toronto's polyphase grid is a clusterfuck as it is implemented today. For
> myself, I don't see hydro dropping voltage on two legs of the residential
> grid in order to test a highly computerized streetcar.
> 
> I can see them frequency stepping the power at the isolation nodes of the
> CNE grounds before converting to DC power. You don't have to touch the
> whole grid, just the parts attached to the DC inverter. Kind of a pre-wash
> cycle in power laundry.
> 
> Hydro is working all over the city to rectify some of the more serious
> load balancing issues generated by considerabble over optisim in the
> effective technology of the day the grid was built. I guess this is to
> stimulate investor confidence before selling the whole dog and pony show to
> someone else.

Well I suppose that with the main distribution being 3 phase power,
but only running 2 phase power in residential areas (which I believe
is generated by transformers from just 1 of the 3 phases in the main
distribution, called I believe split phase, using a centre tap to ground
to give the 2 phases, 180 degrees apart), does result in a potentially
quite unbalanced grid, where the 3 phases could get rather out of balance.
I have no idea if this really results in a big load imballance problem
in general, or not.

> It was the multiple wi fi fields generated when I fired up several devices
> concurrently which i think toasted the hair dryer. This is a known effect.
> I have since found out that it is only modern gfi outlets which have
> sensitivity enough in their measurements of the scope of the surge to
> counter this effect. Older units in fact can compound it.  Ups for a hair
> dryer was my joke of the day.

gfi is ground fault interrupter after all, so anything other than a
short to ground is not supposed to trigger them, while even a trivial
amount of power going to ground should trigger it instantly.

-- 
Len Sorensen