AC DC 250v or 600v

[camillitech]

Paul.......

I am getting worried about the Sunny Island charging regime.

Like you, I think, ? I will retain DC battery charging with my 3 tristars, my Midnite and Morningstar MPPT controllers.

My main concern is that the Sun is out, I am getting PV feed in to the SI Mini Grid, AC Coupling, and my Tristar battery charger controllers go to Float first and the ruddy SI keeps trying to put a charge into the batteries.

Then my 3 tristar controllers then try and dump excess voltage, into my 8kW of dump loads,,,,, aaaaaaggggghhhh.

I will experiment.  

I just turned mine on for the first time in two weeks and decided to start up Harry and do an 'EQ'    I'm sure we'll get there in the end CM. I've not had chance to investigate, too busy building roads and hen runs 

I have a spare interface, but sonething went wrong with it. Will try to find out. If it still works as an overvoltage protection (a 500v zener diode?) then you can have it.

Cheers, Guy

[oliver90owner]

You don't need a 500V zener diode for an over-voltage such as that.  You simply need a voltage divider and use a zener to base load a diverting power tranny.  Not too difficult,  I would have thought as there would not need to be too much power dumped before the voltage was dropped and controlled below the danger level.

[stephendv]

Like you, I think, ? I will retain DC battery charging with my 3 tristars, my Midnite and Morningstar MPPT controllers.

Then my 3 tristar controllers then try and dump excess voltage, into my 8kW of dump loads,,,,, aaaaaaggggghhhh.

The problem is the dump load controllers, all the MPPT controllers including the sunny island will work fine together.  But because you have the dump load controllers connected across the battery they're the ones causing the headache.  I would think that all you need to do is set the float and absorb voltage of the dump load controllers slightly higher (and absorb slightly longer) than all the others and it should work fine. 

[clockmanFR]

Hi Stephen,

And yes, they are set slightly higher, but yet to see how the SI charging regime re-acts?

[rogeriko]

If it is sunny and the batteries are full the Sunny Island will increase frequency to shut down the Sunny Boys and will stop charging the batteries. If there is a load turned on the frequency will drop because the battery voltage will drop and the load will be supplied exactly from the Sunny Boys not from the battery. If the load exceeds the total power from the Sunny Boys then the difference will be taken from the batteries. The Sunny island will keep the batteries at 58v max (adjustable). If the wind is blowing as well a couple of extra amps will send the batteries up to 60v which is where your dump loads are set at. The dump loads then keep the batteries at 60v. This is how it works it is simple. If it is full sun and full wind with no loads attached the solar goes nowhere because the Sunny Boys are shut down and the wind goes directly to the dump loads because the batteries are full 60v. If a load is connected the power is taken from the batteries but because the battery voltage doesn't drop because the wind is blowing the Sunny Boys will not turn on so the wind provides the power. When the load exceeds the wind power the battery voltage will drop and the Sunny Boys will cut in and start producing solar power as well. Its all about the settings. You must make sure the Sunny Island EQ setting and all other settings are below the dump loads. I use 58 and 60.

[camillitech]

This seems to be the answer http://www.navitron.org.uk/product_detail.php?proID=693&catID=148 from Navitron 120v to 600v and only £300 + VAT 

[stephendv]

This seems to be the answer http://www.navitron.org.uk/product_detail.php?proID=693&catID=148 from Navitron 120v to 600v and only £300 + VAT 

If it's a PV inverter then it'll do MPPT sweeps which may not play nice with the hydro.  Can you program in a fixed MPPT curve?

[billi]

.... that seems a good point Stephan , 

As far as i know the Powerspout  has a  heating element inbuilt  to deal with this , but the streamengine?? not i think

[camillitech]

This seems to be the answer http://www.navitron.org.uk/product_detail.php?proID=693&catID=148 from Navitron 120v to 600v and only £300 + VAT 

If it's a PV inverter then it'll do MPPT sweeps which may not play nice with the hydro.  Can you program in a fixed MPPT curve?

Dunno Stephen, but good point, easy enough to try out with one of my spare Sunny Boys. I don't want use one of those permanently as they drop out for a few seconds sometimes if a large motor is started, typically my old 2.5kW chop saw. You can program the Sunny Boy to 'Konstant' but I'm not too sure how they'd cope with the odd visit to 600v.

Cheers, Paul