design techniques for turn-off when grid goes down

[inetdog]

Some might find this PDF on anti-islanding schemes interesting.
It is not in any way a how-to, but discusses some of the strengths and weaknesses of different methods.
It addresses specifically the extra problems which arise where the PV GTI is part of a Distributed Generation scheme in which, apparently, the load can be expected to be controlled to match the available power or other variable sources are connected to provide load matching. This negates the simple passive islanding detection methods.

[bcroe]

Foc

Also, I'm just finishing a 3 phase FOC AC controller that's around 150kw, and the code is open. Turnakado devel also is doing AC FOC open source.

Please define FOC, at least the first time it shows up. Bruce Roe

[bcroe]

False Tripping & Recovery

Another side of the discussion, is to understand how the anti island function could impact
the installation details. For example, if an inverter attempts to observe line impedance,
than a longer than normal inverter AC connection would increase the observed impedance,
possibly increasing false tripping.

Another side of this, is understanding how the inverter manages to get back on line, after
a trip. Manual, automatic, influence of multiple inverters? Bruce Roe