Navitron Renewable Energy and Sustainability Forum

WIND TURBINES => Wind Turbines and associated systems => Topic started by: welly on August 05, 2006, 09:18:37 AM



Title: Running PCs through an inverter
Post by: welly on August 05, 2006, 09:18:37 AM
Hi,

We work from a home office, and are looking at for a wind turbine that will contribute to the power usage.

Actual usage (which seems quite high) aside, I am led to believe that sensitive equipment requires a true sine wave inverter, and that PCs qualify as sensitive equipment.  Is this actually the case?

I think my real question is: will the inverters that form part of the Navitron package (probably 1Kw turbine package) run PCs, or will I have to source a true sine wave inverter elsewhere?

Does anyone have experience of this?

Many thanks

Welly


Title: Re: Running PCs through an inverter
Post by: Antman on August 05, 2006, 09:56:02 AM
Welly

Whilst I don't have experience of running wind turbines, as an Electrical & Electronics Engineer, I do know about PC innards...

Most PC and peripheral equipment utilises switch-mode power supplies. The input stage of a SMPS consists of a bridge rectifier and reservoir capacitor to turn the 240V ac into 320V dc (which is then 'chopped' into a transformer at high frequency to produce the low volatge isolated supplies).

As such, the stability and waveform of what you supply at the 'mains input' does not matter and will be unaffected by the supply being non-sinusoidal.


The only exception are some of the plug-in-the-wall black box power supplies that incorporate mains transformers (known as 'linear supplies' rather than SMPS). You can usually tell by the weight - if it's relatively heavy, it will likely have a transformer. Plug-in SMPSs usually have 'flatter' cases as well. These are sometimes used on routers, external modems etc.
Transformers may suffer in the long term with non sinusoidal supplies, since the current will increase compared to a true sinewave supply. This can cause additional internal heat that may cause the thermal fuse in the transformer to fail.

However linear supplies can usually be replaced by a SMPS equivalent from the likes of CPC ( http://cpc.farnell.com ) for low cost.

Regards

Antman


PS  You need to ensure that a 1kW turbine will produce sufficient power for a PC setup. Bear in mind that the turbine will not generate full power unless the wind speed is sufficient and that a PC, monitor, laser printer, scanner etc will draw at least 600W - 900W (0.6kW to 0.9kW) continuously. Obviously depends on specs etc but needs considering.


Title: Re: Running PCs through an inverter
Post by: welly on August 05, 2006, 10:29:26 AM
Thanks for the info, Antman.

A brief survey of our equipment shows a couple of the smaller devices have the large 'black box' power supplies that you describe, but the bulk of the equipment plugs straight in.

As far as power usage is concerned, I have a power monitor plugged in to the whole office setup, and have measured usage over a typical 7 day cycle.  We used approximately 36.5Kwh over that period, and usage peaked at just under 1200w with everything running.

There are taking some measures to reduce this a little (printers are switched off over the weekend, monitors always off when not at our desks, etc), but taking this as a guide I am under no illusion that the 1Kw turbine will supply all the power needed.  Our aim is simply to reduce it as much as possible within the relatively small budget we have available.

A 1Kw is probably about as big as we can afford to go, once you add in all the extras needed.

Many thanks

Welly




Title: Re: Running PCs through an inverter
Post by: Phil on August 05, 2006, 12:22:37 PM
Hello,
   I have a Navitron  300 watt turbine and use the Inverter that came with the package,  I run a PC/Printer  with no problems at all,  in fact the inverter Ivan supplies is incredibly economical and draws very little power when on but not in use.  so I leave it on constantly !





 


Title: Re: Running PCs through an inverter
Post by: switchoffthelights on August 05, 2006, 01:24:26 PM
I have a pc in my van running off an invertor it works fine

Gary


Title: Re: Running PCs through an inverter
Post by: Ivan on August 05, 2006, 05:16:37 PM
The only thing you are likely to find when running PCs on modified sine wave inverters is that sometimes you will get some faint interference lines on the monitor screen. It does not affect operation.

Ivan