How to choose 3 phase choke inductance value

[yzou_ua]

I'm trying to integrate my generator into grid thru. a AC/DC/AC converter and then a choke. My generator is: 220V, 7.5HP, 21A. DC bus is 400V. Suppose only 30% of nominal power transferred to grid, what's the current requirement on choke current on each phase?
Is it like, 7.5*746*30%/400=4.2A ??
Also, how to choose choke inductance value?? Just rely on cutoff freq. ??

Thx a lot!!

 

[RCinFLA]

Re: 3 phase chocke issue

You will have legal / permit issues connecting backfeed to grid. Not all utility meter work in reverse. Generally the newer ones don't, probably on purpose by utilities. Many of the new meters just add any back fed power to your consumed electric reading so you pay more, as if you actually used the power from the grid. Depending on where you live you have to get your local electric utility approval and they add a second back feed meter. That way they can pay you a fraction of what they charge for power even if it goes right back into your forward meter on your load consumption at their normal rate.
It is a catch22, even if you just tie it on your side of incoming power meter, if you produce more then you consume you pay for what you gave them.

The easiest and legal way is to buy an MPPT controller that is already UL1791 approved. Since output is less then 600 vdc you can find many Grid Tie inverters that will work with it.