[clug] Exercise and pay the bills! [SEC=UNCLASSIFIED]

[steve jenkin]

Steven Ring wrote on 9/2/09 1:09 PM:

> Rightly so. I did a little investigation last year as to the
> effectiveness of anti-aliasing devices. Researchers in this area seem
> to rely on statistical analysis techniques to guage the probability of
> an anti-islanding device (based on voltage/phase analysis) failing to
> disconnect from the grid in the presence of other local PV systems.
> 
> Present techniques don't seem to be 100% reliable, nor is there a
> standardised solution. So local power authorities are well advised to
> disconnect individual PV systems during a maintenance outage.
> 
> Steven

Is there a 'critical mass' of local generation where the inverters don't
notice the grid has gone down??

I'm guessing if the High Voltage power feed into a 240V 'ring' is zero
(i.e. all local power supplied locally) then the 'island' would stay
active/live.

BTW, anyone know if power can get fed back through into the High Voltage
system?

Canberran households are both relatively wealthy and environmentally
conscious. It's to be expected there will be pockets where gross power
input on high-sun days will exceed local use.

Will the power flow back up the transformers?
Are they built for that contingency?

s
-- 
Steve Jenkin, Info Tech, Systems and Design Specialist.
0412 786 915 (+61 412 786 915)
PO Box 48, Kippax ACT 2615, AUSTRALIA

sjenkin at canb.auug.org.au http://members.tip.net.au/~sjenkin