3kw grid tie

[Seedler]

Hi all,

I have installed a 3kw grid-tie turbine from china, connected to a 3kw windy boy inverter.  My question is to do with the voltage.

I live in N. Ireland which has a grid voltage of 230vac 50Mhz.  The inverter willnot start pumping power into the grid until the turbine is above grid voltage (around 240vdc),  but the inverter willnot connect to the grid until the voltage stays above 290vdc for at least 3 minutes.  There is alot of wasted power there between 240 and 290.

Is there any way of slightly boosting the voltage before it goes into the inverter to get it to connect quicker and performe better at low wind speeds?  I was thinking of a transformer but I heard they put a drive on the turbine.  I'm just looking for a slight voltage rise.

When it is connected the inverter will be putting out around 1kw at 290vdc.

The turbine puts out max power at 480vdc.  It is 3 phase 3 wire from turbine to controller.

Thanks,

Damien.

[Nando]

DAMIEN:

You need an over voltage protection for the windboy.

You need to tell what the frequency is around the 200 volts output to see what type of boosting is required.

Also if 3 phase the way you are converting to DC and where.

Transformers can be used if properly done.

What is the input voltage operating range of the WindBoy?

Nando.

[Seedler]

Nando,

The inverter can handle dc voltages upto 600vdc.  The windturbine controller switches heaters on at 480vdc and if the voltage stays above 480vdc the controller shuts the turbine down by automatic short circuit,  the turbine will connect again after 20 minutes.

How do I tell the frequiency, and is it of the ac from the turbine, or the dc to the inverter?

The 3 phase ac is converted at the controller by a 3 phase bridge rectifier to 2 wire dc, which then goes to the inverter.

The spec of the inverter is:

input voltage range - 268v to 600vdc (although it will feed to the grid at 240vdc)

nominal dc operating voltage - 350vdc

Dee.

[vawtman]

Hi Seedler

 Any chance for a link to the place you bought it from?

 Thanks

   Mark

[Seedler]

Vawtman

The link is:  http://www.srmchina.com/hm-windturbine.htm

Mine is the 3kw.  The picture of the one shown on the site is actually mine.  I sent them in the picture a few weeks past.

Dee.

[vawtman]

Hi Dee

 The frequency would be measured on the ac side.

 Do you know the number of poles in the alt(didnt see that)

 I didnt realize that direct grid tie needed to be so precise.

 You may be better off putting a battery bank in there before the inverter and boosting from the bank.

 Dont try unless others think it might work though.

 Hoping to help and learn more on these.

 Have Fun

[Seedler]

Hi everyone,

I just got this diagram of a transformer from the manufacturer.  It is fitted between the turbine and controller.

http://www.otherpower.com/images/scimages/2068/CAHCOBPX.jpg

Just gotta see if I can get one, or get one made.

Do transformers act as a short circuit?

Dee.

[(unknown)]

Seedler,

If you don't mind could you tell us more about your 3kW Chinese Wind Turbine?

1. How long ago did you buy it?
   
2. How is the performance?
   
3. Is it reliable?
   
4. Did SRM ship it directly to your house or place of work?
   
5. What was the cost of shipment?
   
   

There is a lot of price difference between SRM and American made turbines. For example a 1kW Bergey or Southwest costs about $2200 compared to a 1kW SRM for $637 plus cost of shipping from China to USA.

Chinese manufacturers will make whatever you want and at various price levels. The quality depends on the price you for it.

Looking forward to hear from you

Mir

[Seedler]

Mir,

Sorry for the late reply.  Its a 3kw grid tie system.  The turbine controller and dump load are from srm.  I purchased the grid tie inverter from here in Ireland.  At the min there is a slight problem with the system,  its basically my own fault,  the nominal inverter voltage is higher than the nominal turbine voltage but I plan to fix this with a transformer that srm are helping me design.  Thats one thing I can say, they are very helpful.

Anyway its been up and running for about 4 months now, and working well (except for the voltage thing.  It means I loose a bit in light winds).

I'm empressed by the controller, its totally automatic.  I dont even have to worry about it.  In a strong wind it will just shut itself down.

The turbine, blades, controller, and dump load cost me $3000

I purchased my 3kw windyboy inverter for around the same, and made the tower myself.

It was shipped by container to Dublin port which is about 100 miles from me for about $50 or $60.  I then got it picked up by a shipping agent but I could have drove down and got it myself.

Shipping took just over a month.

All round I am very happy.

Dee.