Video of the design challenges of substations when lots of solar is in play

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Also, very interesting mechanical control of transformer taps.

 

[Guest]

YES!!! I have heard this explained verbally before, but never "pictured" it till now. 

I bet you this is probably the main reason why the likes of CoCT is so reluctant to have home users en-bulk feeding back, even more so to create a market to feed back to the grid.

[SilverNodashi]

9 hours ago, The Terrible Triplett said:

YES!!! I have heard this explained verbally before, but never "pictured" it till now. 

I bet you this is probably the main reason why the likes of CoCT is so reluctant to have home users en-bulk feeding back, even more so to create a market to feed back to the grid.

That, and it's a safety risk for the guys working on the power lines. Imagine getting onto a power line and being killed cause someone in Cape Town forgot to turn install an anti-islanding device between their 300W Victron inverer and the DB box in the street...

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2 hours ago, SilverNodashi said:

forgot to turn install an anti-islanding device between their 300W Victron inverer and the DB box in the street

Forgot!? More like skipped it because it was too expensive. Jokes aside though, the blue stuff has active anti-islanding, what they don't have is two disconnect switches in series (of which one must be mechanical), and... I would be mightily impressed if the little 300W inverter manages to drive the big transformer in the street without overloading :-)

[SilverNodashi]

13 hours ago, plonkster said:

Forgot!? More like skipped it because it was too expensive. Jokes aside though, the blue stuff has active anti-islanding, what they don't have is two disconnect switches in series (of which one must be mechanical), and... I would be mightily impressed if the little 300W inverter manages to drive the big transformer in the street without overloading :-)

Our house connects straight to a DB, then to a transformer some 2KM away. So upto that point a sparky's life could end quickly if someone backfeed onto the grid. Especially since they're replacing power boxes all around town and expect the wires to be dead. They box across our house was gone for two days with wires sticking out the ground, while they had to repair a water pipe first. 

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5 minutes ago, SilverNodashi said:

So upto that point a sparky's life could end quickly if someone backfeed onto the grid

Yup, the example I use is the "line severed by a backhoe" scenario, if you can somehow do that without shorting any wires while the GTI is exactly inside its NDZ (non-detection zone), then someone trying to fix that line could get injured. That's why inverters must have an active anti-islanding component, and for that my analogy is the man riding a horse while leaning slightly left, so that a broken stirrup sends him to the ground immediately. Thankfully the Multi has an active component :-)