single phase motor as grid connected dc to ac rotory converter

[odbob]

I thought this was simple, just drive a squirral cage motor above syncronous speed, and using the excitement of the connected grid, hey presto power into the grid, no doesn't work? am I missing something ?

[Alan]

Quote “ I thought this was simple, “

Yup it is that simple until you comply
with G83 / G59.  Then it gets involved

Regards

Alan

[Richard Owen]

Motors as Generators, Nigel Smith. 978-1-85339-645-8

[odbob]

Alan, if it's that simple, tell me what I am doing wrong, the question of safety was not asked
Richard, Nigel Smith. I don't understand the numbers, please explain

[guydewdney]

Thats the isbn number I believe - Nigel has written a well known book on this subject.

[Richard Owen]

Alan, if it's that simple, tell me what I am doing wrong, the question of safety was not asked
Richard, Nigel Smith. I don't understand the numbers, please explain

ISBN as Guy says.

You shouldn't connect anything to the grid that won't auto-disconnect if the grid goes down.

The leccy boards don't want 'islanding' where a section of the grid may still be live (because of your generator) if they are going to work on it.

[Alan]

Quote " Yup it is that simple until you comply "

Forty years ago, common sense prevailed.

A 13 Amp generator will not supply the whole U.K. capacity
if the grid fails.

Regards

Alan

[odbob]

I'm still looking for the answer as to why, driving a small single phase sqirrel cage motor at above syncronous speed, I cannot get it to produce power into the grid.
Please don't keep explaining safety aspects, as this is already covered, I was around before G59 let alone the later regs, and so safety is definately not an issue, I am hoping that there is someone who can explain in electrical terms why my little experiment is not working

[johnrae]

Odbob,
How do you know you are not "exporting" power to the grid. 

Alan
Your house, along with others on the same circuit, is serviced by a transformer.  If the electricity board need to do work on that service circuit they open the transformer outlet isolator to "kill" the line.  If you then have a home-brew generator back-feeding the line then the line is not dead and potentially exposes the service workers to ziggies.  Hence the need for home generation systems to be line monitoring so they go off-line if the line fails.  Simples

[Richard Owen]

ziggies. 

 

[odbob]

This is precisely why I very rarely use this forum, you never get just a straight answer to a question, without being bombarded with other nonsence.
Safety is a very important issue, one which I take very seriously, but that was not the question, possibly, there is no one out there with a precise answer to my original question and in which case I shall look elsewhere, so far thanks for nothing

[SteveH]

 The answer you get is only ever going to be as good as the question you ask!!!!

 When it comes-down to answering questions on the subject of (Potential Lethal) mains voltages, then expect anybody who has any experience in this area to be very circumspect. This is an open forum, & every time somebody proffers advice on the subject of Main electricity, they are putting their own necks on the line.

 I suspect the people who have replied would like to know what you have done to satisfy G83/G89 before they explain in full why you need to accurately sincranise to the mains frequency in order to get this to work....

 I'm assuming the sincing is part of the G83/G89 regs & that's why you're getting the arms length treatment...

[guydewdney]

there is no ranting about safety  - there is just mention of the current relevant regulation wrt exporting electricity. We have no idea what you are doing - for all we know you are exporting several kw for months on end with your 'experiment' - or it could just be 10 watts for thirty seconds - hence being sensible and checking that you arnt about to harm an innocent line worker.

Can you provide more details of the equipment? What is the plate speed of the motor? What is the speed you are running it at? How are you measuring power / current flow? If there is energy being used by the driver, more than just windage losses (check by spinning without grid connection), and there is current flow - then by definition you must be exporting.

What motor are you using?

[odbob]

It's sad and possibly a very dangerous world, that you lot believe that you are the only ones who have knowledge of the safety requirements surrounding grid connected private energy sources.
I repeat that I have full knowledge of these regs, but so beit, I'll continue to experiment, and no doubt in your eyes, I will at some point succeed, and then go on to kill people, I know I won't, at least, not with this full kit.
Oh and by the way, if you read the thread properly, single phase and small was mentioned

[Alan]

Quote “ Its Sad “  Get a life.

The name. Od Bob sums it up.

Quote from Steve. “  The answer you get is only ever going to be as good as the question you ask!!!! “

Correct. Think before you write.

Its not even Full Moon time.

Regards

Alan