Grid Tie Inverters

Discussion in 'Connecting to the Grid' started by murray2paddles, Aug 1, 2009.

  1. murray2paddles

    murray2paddles WindyNation Engineer

    Wow, for me you have wind I am sooooo jealous of. I am sure you will be the envy or many readers !
    The part I like reading about is that you are doing projects with your children,. That is great !

    I live in Manitoba, Canada. on the shore of Lake Winnipeg. We are usually still racing dog sleds when others are surfing.
    With the extreme weather changes we have it forces us to be creative and we must play with the solar energy projects to accommodate the hot and cold temps.
  2. BeachBum

    BeachBum WindyNation Engineer

    It's been 10 days since I emailed Marcel, with no reply yet. I sent him a second email today. Do you think he is too busy moving to his new warehouse to check his email? What would you recommend? Are you still in regular contact with him? I will try to be patient before calling overseas.
    Thanks, BeachBum
  3. murray2paddles

    murray2paddles WindyNation Engineer

    I will try to contact him. Will let you know how I make out.
  4. windyguru

    windyguru WindyNation Expert

    If you need to call, use Skype on your computer. It will only cost a few cents per minute!
  5. BeachBum

    BeachBum WindyNation Engineer

    Great Idea! Thanks, BeachBum
  6. BeachBum

    BeachBum WindyNation Engineer

    Answering your private question, here is the picture of the SWEA Inverter with 2 extra boxes to handle the Windy 750.

    Attached Files:

  7. murray2paddles

    murray2paddles WindyNation Engineer

    Beach, Thanks for the photo, I also have that one from Marcel.

    It could make sense that if you add more inverters eventually you might be able to carry the incoming Volt load. ?? Maybe !

    But what does not add up to me and I am not satisfied with is the fact that I have a 750 watt turbine and it feeds 1000 watt inverters.
    That is a total of four, 250 watt inverters ! SWEA suggested to me that the four inverter would be an over kill and act as a safety back up and it would probably never be used.
    Regularly during a decent wind those FOUR inverters cannot handle the amount of current produced. Total Volts.

    The high Voltage turbines and the plug in inverters which usually have a Volt in range of 21 V to 56 V, simply are not a good match.
    They function well in winds up to the 15 mph range but after that the power increases too much for them to handle and they are in a safety shut down mode which is of no advantage to anyone !

    To match up with those plug in grid tie inverters you must match them with with low Volt turbines .
    Or as I suggested to you there is a product from Windy Girl ( Josh showed me this one ) that is a rectifier that will control total volts in.

    I have talked to others who already have had the same experience as myself ( that translates to having made mistakes already from hands on experience ) and they all have gone through the same learning curve as myself and are also looking for solutions.

    As far as towers go, many of us are moving towards bigger / higher, usually a minimum of 3 inch to 4 inch pipe and 40 ft and higher. This calls for a standing / tilting mount that is not attached to a dwelling.

  8. BeachBum

    BeachBum WindyNation Engineer

    All the things you just said are true. The important thing to remember is that your SWEA boxes were "set" to the lower output of the 500, compared to the 750. You can go into the SWEA "sit.exe" program in the inverter box and change the starting voltage and steepness setting on each box to accomplish the same thing as the WindyGirl. This should give you more usable amps and slow down the turbine, at least this is what I understand from Marcel. I admit that you have so much more experience than I, just please consider changing the steepness settings first. Have you ever used the programmer to adjust the boxes? If you need it, I have the distributor passwords and have been learning this program. You know I'll do anything to help you with this. Maybe Josh can provide use some more data comparing the two PMA's output, so we can come up with better inverter steepness settings for the Windy750. I'll probably be experiencing the same problems you're dealing with now, as I intend to use a SWEA programable inverter on my Windy750 when Josh sends it to me. I feel like a kid waiting for Christmas to arrive.
    Your friend,
    p.s. When you attach the programing cable to the box, make sure the flat side of the plug is facing the ROM chip. It's possible to plug it in backward. You will need to plug a 12 Volt battery to the green plug next to the fan to power up the CPU. Ask me how I know this. :roll:
  9. murray2paddles

    murray2paddles WindyNation Engineer

    Hi Beach

    I have all the cables / password and such to do the inverter tuning, but as last message to you the lap top I use still needs the hard drive replaced due to a virus.

    The difference I see with Windy Girl and SWEA is the Windy Girl rectifier will control the total Volts in at for example if you purchase the 60 Volt one.
    Then each SWEA inverter box can then be tuned to work with the 56 Volt maximum using a controlled Volt input.

    Where the SWEA we are dealing with a non controlled amount of Volts coming in and each inverter box we are trying to tune by sharing that total input load.
    The braking is supposed to kick in to control the turbine but the dump loads are allowing an excess of power through and the boxes are shutting down.

    Now the good news, we have been experiencing 15 to 20 mph winds for the last 1 1/2 days. For the first time my inverter boxes are working properly.
    In the past when ever the boxes received a high input of power or started to heat, they would go green light on and blinking red. This would stay this way for up to 5 minutes at a time until they reset. All afternoon they have preformed differently. They would be green on and when ever a high power surge came through the red just blinked momentarily and then the box was blinking steady green again transferring usable power to the gird.

    I know the talk about blinking lights will just have others on the forum shake their heads and say what the ........!
    But for you Mr. Beach, I know you will understand. lol

    You asked about the difference between the 500 and the 750 for amps and Volts. I also do not have that info but have requested it a few times.
    The feedback so far has been that they both can easily exceed 100 Volts. It would be nice to have real data though and it would make life easier when matching to other products.
    Well, back to watching my meter turn backwards...
  10. dlmcbm

    dlmcbm WindyNation Engineer

    Hey, I am looking into GT now myself. I like your write-up here. on the battery banks you talk about all that they will do with a GT is act like a voltage buffer. If you have a 48v battery bank you can throw 50,60,70v at it and never get much above 48v. I think you said the inverter would draw the bank down to 24v or close to that. I would use a 24v bank then. when the batteries are fully charge then the voltage gets a little higher it will dump into the grid and not keep the batteries drained all the time. unless the GT has a voltage control built in you will need to run one or a battery bank to keep from cooking it. I have found a 300w on ebay just for wind ... 33618417ae It has a built in dump load and if that cant handle it it will disconnect it. Hope this helps ya and keep us informed. Do you have any outputs for your GT's? Are they what they say they will do?
  11. murray2paddles

    murray2paddles WindyNation Engineer

    Yes the battery bank is used as the buffer to control the Volt amount. When you say it will not get much above the 48 V. Believe me it never will. The grid demand will take it immediately as soon as it hints of reaching the Volt level it can take from. your battery bank will always stay below its suggested level.

    The ones I am using now are both working fairly well. But both require dump loads, electronic braking and external Volt control and that requires a heavier wire to carry the heat load for the braking.

    I think the inverter you mentioned above and the link supplied by BlueJay ( see below) are much better choices than what I am using now. ... alers.html

    Due to these inverters being so controlled by intelligent computer software there are so many positive advances being built into them constantly. It is like buying a computer and as soon as you walk out the door it is obsolete due to another one being made better.

    I will also be choosing a new inverter type very soon. I have a few 1 kw towers to put up and one 2 kw tower yet this fall. We are choosing a new inverter that has a very high range of Volt in and they will also build to meet your individual turbine requirements. I will be posting more information on both the inverter and the turbine shortly or as soon as I have accurate information to share.

    What I have learned along with discovering what is required in the way of inverters to hook up successfully to the grid is the choice of power your turbine can produce. If you really want to make a difference in your utility bill you will need a turbine capable of producing high Watts. Example, if you have a 250 watt turbine and inverter too match you realistically will be producing around 50 to 100 watt and only reach the 250 in extreme winds. So if you are producing 100 watt don't expect that to make a dint on your meter. One light bulb on in your house and it has used up all that new inverter power of 100 watt .

    I will always say too "do what I find the least amount of fun". Take the time to discover how much your household uses in one week or month and then you will have a better idea on what size of turbine you will need or at the least you will have a better idea on how much of an impact your smaller turbine will help you out.

    I really wish someone would have sat me down and told me this stuff before I started, man it would have saved me lots of money and time. But then maybe I would have been to stubborn or lazy to do the ground work first.

    anywho, end of this short story.

  12. bluejay

    bluejay WindyNation Engineer

    I just recommended to the ensupra(makes GTI's) that it would be nice to have a circuit that pushes the dc load onto other post to run a dump if the grid turns off..The grid would be the trigger to direct the flow.Either convert to ac and feed the grid or allow the dc to just flow thru to a dump load.... :geek:
  13. murray2paddles

    murray2paddles WindyNation Engineer

    Bluejay, no kidding, you are right on. when I am using my grid tie and there is a storm with a great wind, too often the grid goes down due to trees coming down and taking out the grid lines. It is so depressing watching that grid tie inverter braking the turbine due to no grid available and my other turbine that is feeding a bank is doing its thing producing lots of hydro. What a feeling of lost opportunity.

    And that is another story, sometimes the grid is out for a whole day and during those constant high winds that turbine is braked to a standstill ( no blades turning ) What amount of ware is happening to that turbine to be braked in that force of wind and for long periods of time. Just another real time adventure of using a grid tie system, heck never mind the pepsi, pass the gin please. :ugeek:

    Blue, let us know if you get a response from them.

  14. bluejay

    bluejay WindyNation Engineer

    They emailed me back and the engineers are looking into how it could be done.Even if they dont swend me a few to try for the idea at least I get the GT I want for my system! :D
    I put the blue saphire bombay away along time ago.sorry..But grab that blueberry and flip that vape on....Love my card and state.. :mrgreen: Alcohol is dubbed the dum-dum juice in my household...
  15. murray2paddles

    murray2paddles WindyNation Engineer

    heck my wife and I don't even drink, nor is it allowed in our house. . I was just teasing one of our other forum members.

    Good for you on following up on this. I have been crying about it for a long time but never did anything about it

  16. Marcel

    Marcel WindyNation Engineer

    murray thanks for the nice words.

    the dc input is 21 volt - 55 volt.

    if anyone has some further questions please mail me.
  17. murray2paddles

    murray2paddles WindyNation Engineer

    Good morning Marcel.
    Good to see that you found the Windy Nations site forum.
    I will respond to a few of your questions you raised in your email.

    But first an update on performance of grid ties after our last storms.
    The same winds we received during the report on the Windy 500 & Power Output.
    The SWEA inverters were matched up with a Windy 750 only this time we had the added benefits of using the furling tail system and new tuning of the inverter chips, thanks to Marcel.

    This was the combination we had been waiting for, it sent turbine power to the grid all through that huge storm. ( this storm was rated as a weather bomb by many USA states and Canadian Provinces ) and did not have to shut down at all due to high volts in or overheating.
    The benefits of course was watching the meter turning backwards !

    The furling tail system was able to move the turbine out of the direct wind a little earlier than the Windy 500 was set for. This was good for the 750 while feeding a grid tie inverter system that is rated at 21 - 55 V in.

    I also had one other grid tie inverter in use with a Windy 500. This inverter was purchased from China and rated at 1200 WAtt, their recommendations not to use a turbine rated over 600 watt. I had melted this unit before using a Windy 500 but this time was different.
    Now we attached an SWEA AP box controlling the Volts in and an SWEA dumpload. For the first time this grid tie worked great and survived this great storm as well. We did not have a furling tail on this unit, it would have been interesting to record high amps / watts from this combination.

    We had been using a safety relay supplied by SWEA on the Windy 750. This was a relay system that would brake the turbine during a grid out situation but we found that the amp rating of the relay was too low for the amps provided by the 750. Rather than try to use the same relay system with a higher amp rating one of our forum members ( mark 99 ) has built a relay system that will transfer the turbine power to my battery bank when the grid power goes down. This is what we have all been asking for, to not lose all that potential power due to grid failure.
    Mark has tested the new relay system on his turbine and it has now been mailed to Canada to be tested on my Windy 750 with the SWEA grid tie system. "Mark is the MAN "
    We will keep you updated during testing.

    Last words today would be: we can only give reports on what we are testing in real time and not what else might be available so the Windy 750 and the SWEA system were a good match and using the SWEA components with the inverter from China & the Windy 500 was also a good match.
    Weaknesses: Tuning of the SWEA chips are not easily accessible and requires a computer, it would be much more user friendly if the customer was able to change the chip tuning with an external hook up or dial system.
    Inverter manufacturers should have an option relay to allow the customer the choice of direction of V in the event of a grid failure rather than trying to brake the turbine during strong winds.

    My next projects will be using a 1 kw and and a 2 kw turbines. I will be testing a different type of inverter with those turbines and will report on them at a later date.
    If you are interested in making contact with SWEA please use the email address supplied in the thread above from Marcel.
    All for now
  18. windyguru

    windyguru WindyNation Expert


    Thanks for the report. Very informative.

    I am excited to hear about how that relay works. I think a lot of people would be interested in it and maybe it would be something SWEA could build and market to customers. You and Mark could sell the intellectual property to them :D

    Do you guys plan on getting your grid ties UL listed? That would be so good if you did that!
  19. Marcel

    Marcel WindyNation Engineer


    yes we are very busy with ul inverteres.
    [attachment=1:1kdzce75]SWEA UL inverter.jpg[/attachment:1kdzce75]
    we have to do a couple of last tests and than to the test house. you have to take care of a lot of ul things. :?

    i think it's quite smart to switch a relay to a battery bank, in this way you never lose power.

    in fact we already have designed a safety relay system build inside the ap-box. this device is also in test phase at the moment.
    [attachment=0:1kdzce75]swea ssd build in ap-box.jpg[/attachment:1kdzce75]
    I'll let you guys know when it's all ready and fully tested.

    kind regards,

    Marcel van der Heijden
    Swea Europe BV.

    Attached Files:

  20. windyguru

    windyguru WindyNation Expert

    Hi Marcel,
    Let us know when your UL grid ties are ready for the market. We would be interested in stocking them!

    Does your grid tie software use a MPPT algorithim? If it does, how easy will it be to tune the UL grid tie to a particular generator's power curve? Thanks - Josh

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