Link to bringing wind, solar and rectified AC into one CommonGrid Tie Inverter

[Murray Johnson]

Voltsys Inverter Control Unit
For turbine manufacturers with their own rectifier / dump load and turbine control, the Voltsys Power Control unit allows any wind or hydro turbine to work with the wide range of ABB solar inverters.


Wind and most hydro turbines need power extracted at different rates, depending on the RPM or turbine voltage. This is known as a power curve, or power table, and usually the ratio is non-linear as per the example graph on the left. In the past, wind inverters provided the ability to enter a power curve.Volts Watts Power Curve

The Voltsys Inverter Control Unit provides power curve control for ABB solar inverters, including the Trio and Uno DM range of inverters.

This means that solar inverters can now be used as wind inverters. The load on the generator is increased based on a generator speed or DC voltage and that power is then exported to the grid by the inverter.

SO And if hardware in both WIND and Solar Inverters are the same....is it just a matter of software fixes or maybe just the correct MPPT curves????

[Rob Beckers]

Murray, in theory you're right: A different firmware can turn a solar inverter into a wind inverter. That's exactly what ABB/Power-One did with their Aurora inverters; the hardware was identical for solar and wind, the only difference was the firmware.

However, us mere mortals have no access to the inverter firmware, and without it a solar inverter is most definitely NOT a wind inverter. Solar PV and wind/hydro work very different, one is a current source, the other a Voltage source (that needs very specific loading to perform well, hence the need for an MPPT curve).

I've been watching the Voltsys product for some time now. Waiting to hear from people that have actually used it (and I've sent quite a few people their way, since legal/certified wind inverters are no longer available). It looks promising, depending on price...

-RoB-

[Bill von]

SO And if hardware in both WIND and Solar Inverters are the same....is it just a matter of software fixes or maybe just the correct MPPT curves????
Yes. Some devices (like the Midnite Solar Classic charge controller) can be set to several different profiles, including wind and solar. However, wind systems often need a dump load (or shorting switch) to despin and stop the turbine during very high wind events - so the hardware is a bit different.

[Murray Johnson]

There are inquiries going on about "Inverter Control Unit" CSA (or equivalent) Standards
approvals; suitable Certified rectifier assemblies etc. The first week of March I will attempt to talk to a chief electrical inspector in this region and will keep interested readers informed.
Thanks for the link to a different inverter manufacturer. I'm sure the solutions are out there or will be created.
When you've got reliable; steady electrical production nearly 100% of the time (As say a 10Kw solar array inverter setup); and easily 10 fold production (not to mention nearly another two times as much energy available as waste heat)...then surely its worth trying to capture it.

Thanks

[Murray Johnson]

Yes you read that title correctly. Fossil fuel waste products now in same list as sunlight, low impact hydroelectric, thermal energy from deep hot water sources, biomass AND unfortunately

Small scale wind was deleted from power company eligible sources of Net Metering maybe largely because of exit of standards approved manufacturers in North America and better economics and what the industry has determined to be a less problematic that other solutions such as solar.

As for my flare gas approx 35 KW generation project....the required one line electrical diagram was commissioned though an electrical engineering manufacturer; seven new Aurora 6000 watt wind inverters acquired and the interconnection study by the grid owner was submitted approx. 3 weeks ago.

Proposal application to the utility was genset three phase electrical synchronous AC power generation (with energy source of "carbon neutral" flare gas------>rectified by 6 pulse rectifiers--->fed to paralleled 6000 watt Aurora wind inverters for each of the three phases of the grid's 120/208 45KVA transformer three phase system. Each "wind" inverter" derated to about 5000 watts and with isolating transformers between each inverter; and a common forced air fan system for additional air movement for cooling of the inverter and rectifier heat sink fins. All mounted on a fancy light tower trailer; except for the 100KW genset which will be located near the Net metering connection.
The provincial Chief electrical inspector commented that the theory looked sound; a certifying agency has been lined up and an electrician on standby. There's red tape and lots of it; but a sound effort will be attempted for a 24hr/7dayweek/with enough days of productionenough days to bank 3 years of electrical credits. (A Net Metering Scheme using grid tie as the "battery storage" system.

Then maybe it is time to ask as to why not the utility wouldn't want such production to continue (and be paid something to at least cover the costs associated with 30,000 hours of generator running between tuneups) as a part of utility base load generation.


Perhaps the genset will also be run during very high electrical usage periods when aeration fans or electric motor grain cleaning periods are being used.

Rob I'll contact you when the grid operator makes their engineers decision about this first small scale "carbon neutral" Net Metering project in the province.