Hello,

I am designing a 12 MW GFL wind converter (inverter). Do you think a 2 L VSC with 6 IGBT's can handle the current? the voltage is 690V ac.

 

the voltage is 690V ac.

Why do you want complications to convert / invert AC into what ? Transformers could suffice.


A pretty 12MW turbine...

----> https://www.reddit.com/r/HumanForScale/comments/ovszwt

 

I am designing a 12 MW GFL wind converter (inverter). Do you think a 2 L VSC with 6 IGBT's can handle the current? the voltage is 690V ac.

No.

Based on the massive amount of information you have chosen to keep secret, I *think* that a single IGBT cannot handle 2,899 A.

What is a GFL?

What is a 2 L VSC?

ak

 

This forum is oriented toward hobbyists. Hobbyists do not do 12MW.

 

This is one of those "if you have to ask, you shouldn't be doing it" situations.

Why are you wanting to re-invent the wheel? Almost any answer you give probably leads to compromised safety and performance.

 

No.

Based on the massive amount of information you have chosen to keep secret, I *think* that a single IGBT cannot handle 2,899 A.

What is a GFL?

What is a 2 L VSC?

ak

In my locality there is a large company called "GFL", which stands for Green For Life. It is a waste collection that empties both dumpsters and our neighborhood's curbside trash containers. I rather doubt that they are part of any power system manufacturer.

Consider that 12 megawatts at 690 volts comes to almost 17.4 KILO-AMPS, which will require a whole LARGE array of 100 amp mosfets.
SO I offer a suggestion of an alternative arrangement able to solve a lot of logistics problems, as well as allowing much easier service for the generators involved.
Instead of the generator turned by the wind turbine, which requires a serious gear train to increase the speed, use an adequately sized hydraulic pump to capture the energy. Then route the pipes from that pump down to the ground level and over to a suitably sized set of hydraulic motors, which can spin the generators at whatever speed is required directly. And because dividing the flow is simple, multiple generators can be used, allowing redundancy for much greater reliability. AND, if service is ever required, much simple ground level working, without that high altitude hazard. In addition, all of the power electrical system can also be safely at ground level, much safer to work with when service is required.
The benefit of not needing to adjust the frequency as the wind speed changes should be enough to promote this concept by itself.

 

Consider that 12 megawatts at 690 volts comes to almost 17.4 KILO-AMPS, which will require a whole LARGE array of 100 amp mosfets.

AC power at this scale is invariably 3ø.
12MVA @ 690V 3ø gives a line current of 10,041A. Still far beyond any single semiconductor device.
BTW, my professor would divide your grade by sqrt(3) if you misused it in a 3ø calculation.

 

OK, FRED! What do you think about the concept of a hydraulic power transfer scheme to get the energy down off the tower, with no big gearbox, and delivering it at the right speed/RPM for the generators. In a hydraulic system you have pressure and flow, similar to volts and amps, and the hydraulic pump/motor team working a lot like a transformer to convert the wind turbine torque and RPM to thr required generator torque and RPM, at a distance.

 

Still far beyond any single semiconductor device.

Post #1, second sentence > 6 devices.

ak

 

OK, FRED! What do you think about the concept of a hydraulic power transfer scheme to get the energy down off the tower, with no big gearbox, and delivering it at the right speed/RPM for the generators. In a hydraulic system you have pressure and flow, similar to volts and amps, and the hydraulic pump/motor team working a lot like a transformer to convert the wind turbine torque and RPM to thr required generator torque and RPM, at a distance.

I don't have any experience with hydraulic systems but I suspect that high torque at low RPM will always translate into massive (heavy) machinery. While I find the concept interesting, I think that you're probably just trading a heavy pump for a heavy gearbox. Working out the requirements of the pump and motor would settle the question. Moving the generator to the ground might reduce the total weight at the top of the tower.

Also, the swivel coupling that would allow 360° rotation so that the turbine always faced the wind would probably be a major PITA. The weight of the high pressure piping would probably be comparable to the cabling.

A better move might be to make the generator in the tower 6900 or 13800 V. Both very common voltages for machines at that power and probably a little lighter than a 690V 12MVA machine. But that doesn't solve the problem of going from high torque to high speed.

 

OK, unless I goofed someplace that is almost 6000 amps for each phase leg in a 3 phase system. So if each leg has an array of SIX of the 1000 amp 1000 volt devices then possibly. BUT the timing will need to be perfect, much better than really close.
AND CERTAINLY, this project is beyond asking us to help.

 

Post #1, second sentence > 6 devices.

ak

I interpreted 6 devices to be a full wave 3ø bridge. But still 6 devices /phase would be about 1000A/device in a bridge configuration. The full wave bridge would be 36 devices.

 

I don't see anything 'green ' about wind turbines.
All the energy they remove from the wind results in less cooling air flow across the land / sea.
So the earth gets warmer and becomes further global warming.

 

I don't see anything 'green ' about wind turbines.
All the energy they remove from the wind results in less cooling air flow across the land / sea.
So the earth gets warmer and becomes further global warming.

Given that every bit of the energy from wind comes from solar heating, which is affected by the atmosphere transmission and absorbtion, removing energy from the air stream should be a benefit. IN ADDITION, converting wind energy into useful electrical energy is a better alternative than fuel burning generation. AND wind is a constantly renewed energy source.
One more thing is that the wind is certainly not always a cooling thing, and often part of nasty weather.

 

Wherever the energy comes from that creates the wind, if that airflow is reduced, as in any air cooling system, the base temperature will rise.

In years to come, I bet this will be seen as no different from using oil, coal or gas, when they were first used for mankinds convenient energy production.

'Part of nasty weather'??

 

WHERE ELSE COULD OUTSIDE ENERGY COME FROM, other than the sun?? Every bit of out weather is ultimately driven by energy from the sun. AND, what other method of energy recovery results in such low disruption by taking up land area?? And wind energy is available day and night, unlike solar energy. AND, in my area, that "cooling breeze" brings us some really nasty winter storms.

 

I don't see anything 'green ' about wind turbines.
All the energy they remove from the wind results in less cooling air flow across the land / sea.
So the earth gets warmer and becomes further global warming.

troll?

 

troll?

Sounds like it, but on the other hand, not being an engineer is not the same as being a troll. So it's hard to tell.

 

What's your definition of troll?

 

In this country nobody is forced to like something. AND they are allowed to speak.
That does not mean that they have even the slightest grasp on reality.
But also, In this country nobody is forced to have a grasp of reality. I am not sure if it applies to being a troll.
Mister T(deleted) does not like wind turbines because they spoil his view.