Xantrex 6048 Wind/Solar/Battery Question

Denniswingo
Denniswingo Registered Users Posts: 16 ✭
in Advanced Solar Electric Technical Forum #1
Folks

We are having a problem with all ten of our Southwest Windpower Skystream 3.7's and our ten mobile systems.

First of all our configuration is 16 275 watt panels feeding an outback MX-80 MPPT. This is fed into the Xantrex inverter. We have a Skystream 3.7 turbine coming into the wind turbine side (the SW Skystream 3.7 is set up in AC mode).

We are getting a problem where the Wind turbines are braking in only modest wind. The SW windpower folks say that it may be because with our batteries full (from the wind and solar), and no load (these are not placed into service yet), that the SW turbines shut down when the batteries are fully charged and there is no place for the turbine's output to go.

Therefore the question is: Does the Xantrex 6048 have a load diversion controller? We have not been able to find this out conclusively in the literature (one way or the other).

Thanks
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #2
    Re: Xantrex 6048 Wind/Solar/Battery Question
    Denniswingo wrote: »
    ......
    Therefore the question is: Does the Xantrex 6048 have a load diversion controller? We have not been able to find this out conclusively in the literature (one way or the other). Thanks

    NO. It is an hybrid Grid-Tie inverter with battery capability. It only has a grid powered charger.

    You will need a Charge Controller. I would suggest looking at the Midnight series of charge controllers, they are OK with wind, and can divert power to dump load when batteries are full (But I think it's better to stop the turbine when the battery is full, why keep the bearings spinning)
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • BB.
    BB. Super Moderators, Administrators Posts: 33,640 admin
    #3
    Re: Xantrex 6048 Wind/Solar/Battery Question

    The Skystream 3.7's are AC only output wind turbines (as far as I know). So, you are left with "back driving" or AC Coupling the turbines to some off grid pure sine wave inverter that will accept AC input power to charge the battery bank (as the XW, Some Outbacks, and others are known to have that capability).

    I believe the Midnite Classic Controller would only work with DC (or rectified wild AC) wind turbines. I cannot see a practical way of connecting a wind configured classic with a Skystream AC turbine.

    The XW, as I understand, and if it is set in the correct mode (with the correct level of firmware) is programmed to bring the AC line frequency to higher than 60 Hz (North America) which will cause any standard grid tied inverter (including the Skystreams) to "lose sync" or see the "out of range" grid frequency, and go into GT inverter shutdown (usually a 5 minute timeout). This is how the XW inverter controls/limits charging energy into an already full battery bank.

    Once the Skystream's GT inverters "shutdown", it will require the Grid Voltage and Frequency to be stable for 5 minutes before the Skystreams will startup again (and do the whole process over again).

    I believe that one of the original "battery based" Skystream setups used a simple AC contactor between the Skystream and the off-grid inverter. When the battery was charged, the "battery controller" would simply "turn off" the contactor between the Skystream and the Off-Grid Inverter.

    When the Skystream is "off-line" from the grid, I would expect the Skystream internal controller to limit turbine RPM (unloaded horizontal axis wind turbines will over-speed and can self destruct in moderate to heavy winds unless controlled).

    Last I heard, the Skystream would do this by placing a "dead short" on the turbine's alternator output which "stalls" the blades (a lot of torque generated which prevents the blades from spinning quickly).

    If you wanted to use a dump load instead--I believe you could place a dump capable charge controller on the battery bank and set it to turn on a resistance heater (or whatever) at a lower voltage than the XW's "frequency shift" battery setpoint. Many of the Solar Charge Controllers have a dump mode--or you can get a dump controller designed for wind too...

    It would be interesting if you setup the dump controller to control an AC grid 120/240 VAC heater instead of a 24 or 48 VDC heater (and contactor). Not sure if this would have any advantages or not (may be easier/cheaper to switch/control/dump 120/240 VAC Power vs 24/48 VDC battery bus power).

    Would the Skystreams be happier with a dump controller and load instead of the frequency shift/GT dropout function instead of using their internal braking system? I haven't a clue.

    There are issues that you have to be careful of--For example you don't want the XW Grid charger to be "charging" the battery bank (with grid or AC genset) while the dump loads are active (waste of power and money).

    I am no expert on the systems you are asking about--just my general knowledge (limited it is).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #4
    Re: Xantrex 6048 Wind/Solar/Battery Question

    Ok, I did not know the skystream had in internal GT inverter. I would think the install/owners manual would cover all this
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • BB.
    BB. Super Moderators, Administrators Posts: 33,640 admin
    #5
    Re: Xantrex 6048 Wind/Solar/Battery Question

    I am pretty sure that model is only available with a GT inverter in the turbine head--However, I have not kept up on them for the last year or two--So I could be wrong.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    #6
    Re: Xantrex 6048 Wind/Solar/Battery Question
    Denniswingo wrote: »
    We are getting a problem where the Wind turbines are braking in only modest wind. The SW windpower folks say that it may be because with our batteries full (from the wind and solar), and no load (these are not placed into service yet), that the SW turbines shut down when the batteries are fully charged and there is no place for the turbine's output to go.

    If it's all setup correctly with the XW configured for AC coupling, then it sounds like that's exactly how it should work. When the batteries are full, the XW increases the frequency and the inverter in the skystream recognises this as a grid outage and disconnects and applies it's own dump load (or applies it's breaks in whatever form they've built these).
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  • System2
    System2 Posts: 6,290 admin
    #7
    Re: Xantrex 6048 Wind/Solar/Battery Question

    You can use the Morning Star relay driver to drive 1 or more
    relays to drive a diversion load search ebay for some examples.
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  • Denniswingo
    Denniswingo Registered Users Posts: 16 ✭
    #8
    Re: Xantrex 6048 Wind/Solar/Battery Question
    stephendv wrote: »
    If it's all setup correctly with the XW configured for AC coupling, then it sounds like that's exactly how it should work. When the batteries are full, the XW increases the frequency and the inverter in the skystream recognises this as a grid outage and disconnects and applies it's own dump load (or applies it's breaks in whatever form they've built these).

    Thanks guys, this does seem to be the issue. We are seeing the DPLL unlock on the Skystream advanced diagnostic screen and this is when the turbine shuts down. We do have a full up AC inverter in the Skystream and everything is configured (we have confirmed this both with Schenider and Soutwest) correctly.

    This is the first time that we have had everything fully configured and in a retail mode and this is still a learning experience for us. Whether or not it is better to use load diversion or just let the system run as it is is an interesting question. Since we are operating our systems in remote areas, and most of them are in winter locations, it may make sense to use the load diversion and use that energy to heat the batteries.
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  • Denniswingo
    Denniswingo Registered Users Posts: 16 ✭
    #9
    Re: Xantrex 6048 Wind/Solar/Battery Question
    BB. wrote: »
    I am pretty sure that model is only available with a GT inverter in the turbine head--However, I have not kept up on them for the last year or two--So I could be wrong.

    -Bill

    We do have the GT inverter in the head and the system is fully wired to take advantage of the hybrid system.
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