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lief ryan avatar image

Wind Turbines and victron charge controllers

hi, i would like to know if victron mppt charge controllers support wind turbines? if yes could i run 2 controllers in parallel, one with solar and one with a wind turbine?

Thanks

Lief.

charge controller compatibilityHydro and Wind Power
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Hi, greetings from Denmark. Following this interesting thread due to my own wind/ solar project.

I am a solar installer from Gsol Energy Global, we make offgrid and on grid Solar systems for the UN.

In my private project, I am allso building a hybrid system containing wind and solar.

Technical information -

Wind turbine 1kw 3phase Greef generator mounted on 9m mast, with home made blades( vertical )

Victron quattro 10000Va,

Ccgx, lynx shunt can bus,

smartsolar 250/70 as wind input with rectifier, and 10000uF capacitor infront.

Smartsolar150/100 for pv.

Wind break will be added through a changeoverswitch later. I can raise and lower wind tower at will, and the vertical design is not prone to overspin due to the design.

My problem is that windmill it is not transferring power, even though i got strong wind and 60vdc at the pv input side. And the voltage on battery bank is more than 5v lower (51,2v - 57,6 is cycle use)

I was thinking that voltage from generator is to close to the battery voltage, I was thinking about putting a voltage stepup module infront despite the loss..

Any thoughts from you guys?


Hello @Myren

I'll begin with the caveat that I am not a pro installer here.
But very interesting setup you have there, so wanted to give you a temporary reply as we have been experimenting for some time with something very similar.
I am sure others more qualified will chime in, but you are probably missing a piece of equipment between the turbine and the regulator that allows programming of the power curve of the turbine to your regulator and keeps it loaded with dump loads. The Victron smart solar regulators are certainly great for PV but may require a tweak or two to do wind and hydro well.

16 Answers
markus avatar image
markus answered ·

Hello Lief,

no, it is only officially supported, to connect solar panels to the MPPT's.


That does not mean that it wouldn't unofficially work, when you know what you are doing. :o)

I do use Victron Solar chargers with hydro turbines for over a year now, without any issues at all.

The main problem is see in connecting a wind turbine, is a missing storm brake that short circuits the generator to brake in stronger winds and the battery is full etc...

You would have to implement something, but be careful, to short circuit PV input under load can destroy your charger.


And yes, it is possible to connect several MPPT chargers in parallel to the battery.


Regards,

Markus


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Just to clearify, i did never ever kill a Victron MPPT, I just saw what happened with a friends charger, after he drilled through both PV wires... There were bubbles appearing on the surface of the charger. Not nice :o(

Can you please give more details about the configuration of the hydro turbine - MPPT charger because I am trying to add water generator to an existing solar based system?

question asked

regards

amacris

lief ryan avatar image
lief ryan answered ·

hi, thanks for your reply, i'm starting with solar for now and i'll see about adding wind later on.

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markus answered ·

I found something really simple and useful. Matching what I was talking about:

https://www.altestore.com/store/wind-turbines/primus-windpower-turbines-parts/accessories-for-air-x-air-breeze/primus-windpower-wind-control-panel-24v-p11450/


I think this device should be easy to rebuild and optimized for use with MPPTs (short circuit problem).

Amperemeter is rather unnecessary, if you use a Victron MPPT.


As I have actually finished my Hydro Power Installation, I am searching for new challenges.

I will deep dive into some wind applications with Victron MPPTs and bring up a solution and keep the community updated.


Markus


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Hi Markus,

I'm also building a wind turbine and I'm now looking for a MPPT controller. Victron is in my opinion one of the best suppliers. I would like to make a grid tie solution and I'm wondering if there is a solution for it?

Is it possible to connect the battery connection on the charge controller to a grid tie inverter?


Regards Sander

Hi @Lange1975,

I recently tested a wind turbine in combination with a Victron MPPT charger.

Unfortunately it does not work good with a (solar) MPPT charger alone. You would need some overspin protection. The MPPT charger is searching for a max power point and wants the Voltage to be as high as possible, which leads to overspin of the turbine when there is good wind.

You would need an additional Voltage limiting device, which limits the turbine speed.

Additionally, if the wind turbines generator output Voltage is too high and not matched to systems battery Voltage, the MPPT could stall the turbine when there is more power demand as the turbine could deliver at that moment.

Conclusion: connecting a wind turbine to a solar MPPT does not work without an additional (limiting) device, lets call it a turbine controller...

Regards,

Markus

Hello @Markus,

I'm building my own turbine with an PMA based on a F&P smartdrive motor. This motor produces per revolution about 0.608V.

Will this than also give the overspin problem as you described? Or is there still a limiting device/controller required as in the picture?

And is it also possible to use the charge controller and instead of hooking up batteries connect it to a grid tie invertor?


Regards,

Sander

1571935851087.png (196.4 KiB)

On a off grid system, I’ve been running a small 48V/300W (85W@8m/s) wind turbine on a Victron MPPT for a time now.

My experience is that the MPPT only let the turbine spin up when its does the recalculation, and then takes it down again. This gives a short peek that can be up to 140V(See attached image.) But I’ve never seen that it tries to keep the highest voltage possible, that would result in uncontrolled spin.


Important when using a MPPT regulator on a wind turbine:

-The wild DC from the turbine most not exceed the max input voltage of the MPPT regulator. When the regulator from time to time does the recalculation MPP sweep, the regulator reduce the load and the turbine can for a very short time spin up to max. (My 48V turbine can at this stage give up to 140V DC)

-The MPPT regulator can only be in the two stages off (no wind) and bulk (wind). (In absorption/float the turbine will spin up uncontrolled and cause damage.)


One solution to this, which I’m using, is to use a dump/diversion load on the batteries. To always keep the MPPT in bulk, the MPPT regulator absorption voltage needs to be set higher than the voltage that the diversion load regulator starts the dumping/regulating on.

I’m using a Tristar TS-45 in “diversion mode”, that for a 48V system has a maximum power rating of 2700W@60V.

The regulator and the size of the load needs to be able to handle the power of both the turbine and solar panels.

I also have two big capacitors on the input on the MPPT regulator, to smoot out ripple from the turbine.

Just a +1 that I am following all threads like this with great interest. We are looking for a way to use a Victron regulator for wind with synched charge voltage as well as excess voltage for the GX unit to an AC Thor, among other things.
So would also be grateful for any hints of products available for this.

Many thanks


Hello Espen. I have been working on similar setup like you, but are not able to get any power from the mppt. Do you have any ideas of what the problem is..???

I posted my setup at the top of this page.. maybe the wrong place...

Many thanks Lasse

lief ryan avatar image
lief ryan answered ·

i was thinking of using the multiplus to turn on an immersion heater when the batteries reach 100% soc and off again at 95%, could that help avoid the need for a turbine brake? ie just keeping the turbine under load all the time?


@Markus

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markus avatar image
markus answered ·

I would not prefer to do so.

This actually prevents the batteries from being fully charged.

In stormy conditions, this might not be enough resistance and your turbine + MPPT could get destroyed.


I would go this way:

Use 2 rectifiers, one connected to the MPPT and one connected to be shorted by a strong relay and a paralleled switch.

You could then use the relay output of the MPPT or better a BMV, to toggle the relay and short circuit the turbine. Additionally you have a switch, to override.

The 2 rectifiers should prevent the MPPT from being short circuited on PV side.


Might work, may be worth a test ;o)

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To stall the turbine, you can use a DPDT (double pole, double throw) switch or relay.

On the attached image, you connect the turbine on A1 and A2, the battery or charger on C1 and C2. And put a short between B1 and B2.

dpdt-relay.gif (9.8 KiB)
lief ryan avatar image
lief ryan answered ·

i was just thinking of not wasting valuable power, i could use a wind specific charge controller with a built in dump load, but the house is too far away from the power shed to use dc but maybe a cheap inverter connected to the dump out from controller?

i don't actually have anything setup yet so this is still hypothetical..


do you know if there would be an issue with have one victron charge controller and one midnite clasic? the other equipment will be victron multiplus, victron ccgx, victron mppt, pylontech batteries.

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markus avatar image
markus answered ·

Valuable Power wouldn't be "wasted" in the solution mentioned above, but maybe not used 100% efficient. This is also to be considered in a very small wind solution only. As long as the battery is getting charged and you consume power, you can choose not to "lock" the turbine and no dump load is used at all, maybe an additional "lock relay" circuit, triggered by some other wind measurement device would be good to have...

If your set up would involve a dump load, it might work to use a PV inverter, to dump into some useful AC Load. But this is for sure hypothetical. It would for sure be more reliable, to use a DC resistor dumpload.

No problem, as long as every charger is set up with reasonable values.

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lief ryan avatar image
lief ryan answered ·

sorry i should have explained my situation a bit better, i've got 5.4kw of solar which will be way more than i need in the summer but will probably be a bit less than i need in the winter, thats why i want the wind turbine to supplement it in the winter months, i've got 10Kwh of pylontech batteries, they should charge pretty quick from the solar in the summer so i'll have excess power to dump, i want to use it for hot water in the summer cause my hot water and heating are from a wood stove and i won't want to light it in the summer,


another option is (like you said) to have the wind turbine running a grid tied inverter ac coupled to the multiplus, but then i would still be left with the problem of using the excess solar in the summer which is why i was thinking of just having the multiplus turning the water heater on and off at set voltages


Thanks for you help, its much appreciated.

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John Rushworth answered ·
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dod42 avatar image
dod42 answered ·

I have a D400 and have played around with a 100/50 mppt instead and together with the standard TB6 thank comes supplied. Sort answer, not real successful. With just the 100/50 yes it transfers power but due to the way the mppt works the D400 acts like it is not connected to a load, so it spins faster than normal making more noise and eventually does a 360 like it does if not connected. It also didn’t produce any more power than the TB6 which is a PWM controller with dump load. The TB6 is very rudimentary and has no real settings nor monitoring. What I really wanted was the blue tooth monitoring the 100/50 offered. I even tried installing the 100/50 after the TB6 but this also fails as the TB6 doesn’t see the battery voltage out the solar input on the 100/50 so yes the 100/50 sees a voltage at the input from the TB6 but all the current is diverted to the dump load, nothing to the batteries. So far I’m yet to find anything that works better than the supplied TB6 as it seems to control the load to the D400 to keep it spinning at the optimal speed which also means less noise. I think what I need now is Hall field sensor that I can put on either of the output lines of the TB6 that also takes a Bluetooth dongle that just allows the monitoring. I guess I could use something like a BMV but that would be an overkill

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myren avatar image
myren answered ·
  • @Houser, @espen, @lief ryan, @markus, @lange1975, @john rushworth,@dod42
  • Seems like we all have a commen interest in solar and wind together. Especially using victron mppt as wind controller. I have created a group in facebook called solar and wind knowledge group for enthusiasts. You are all invited.
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I don't do facebook but am very interested.


I have a Multiplus II 48/10000 (ESS Setup), MPPT 250/100, Fronius Primo 8.2-1 (AC Coupled), Cerbo GX, and 32,5Kw of Pylontech US3000C. 35xHyundai 395Wp Modules in 3 strings, 2 for the Fronius and one for the MPPT.

My objective is to add an extra boost to charging in Winter but I want the wind integrated (DC Coupled ideally) with the Cerbo GX to control the charging hence the desire to use a Victron MPPT Charger.

Alternatively I've though of setting it up in AC Coupling but woulde again need to find a model that would accept the power copntrol through frecuency shifting like with the Fronius.

I think that if Victron could work a version of an MPPT with a or some brands of wind generators, they would have a hot selling products. Not just for homes and offices/rural projects, but especially also for the nautical market.

If a viable solution is known of, please share it.

markus avatar image
markus answered ·

Hi everyone here,

This thread is quite old now, but to hold my promise "I will deep dive into some wind applications with Victron MPPTs and bring up a solution and keep the community updated. "

@WKirby and I developed a turbine controller device, that can be used with Victron Solar MPPTs to be able to connect wind and hydro turbines.

Here it is:

1629286252191.png

A quick specification preview:

Inputs:

DC main turbine power input; max 250Voc 120A Isc

Outputs:

DC out for the MPPT charger

DC out for a water heater

DC out for a dumpload (failover if the water is hot)

3x 2pin temp sensor analog in (LM335 compatible inputs, can be used as digital inputs);
.) contact type wind speed sensor

.) water temperature

.) dumpload temperature

2x 3pin NC-COM-NO Relay Outputs using small G5V relay. (can be used to lock the wind turbine, or control of a water lock valve, or to control a fan)

Ve.direct port.

BLE port for VC.


A short description:

Turbine power, that is not used by the MPPT can be used to heat water. If the water is hot enough, the dumpload resistor will be utilized instead.

It is also possible, to use only a single dump load.

The controller will take care, to brake the turbine if neccessary and even avoids to stall it.

There is an output available to drive a turbine lock / water valve.


The current development stage is to create (finish) a firmware for the device.


The reason I post it here is to inform the community, that there is a solution in the works.

And I am very interested, in how big the demand for such a device is, to maybe be a motivator (booster) for the work that still has to be done.


Best Regards,

Markus


1629286252191.png (1.1 MiB)
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What is your estimate of price that you would sell them for? (thinking a complete unit but no enclosure)

Hi Mr. Happy,


At this stage it is hard to estimate the exact price for the end product.

The prototypes that exist, have been assembled by hand. When the product is finished, we have to make a plan for mass production, then we have a better view to do a estimation.

But as a rough guess, it will be in the range of a smaller size medium range MPPT.

What do you think, would be a reasonable end user price for a unit?

BR

mrhappy avatar image mrhappy markus ♦♦ ·

Hmm, I don't really have an opinion about a reasonable price for such a unit, but my expectation is that it would be priced as the higher end MPPT's. The reason being the lower amount of produced units compared to the MPPT's. But that's just my expectation. You guys know what you are doing and I think any price you choose will be reasonable. For me, the potential availability for such a unit would absolutely spark an interest to install a wind turbine. In fact, reading this thread has already made me look around for one and study what it's all about...

As is, I'm interested in using at least one of these in a nautical environment. More interested if a VE.Can model is available. Personal opinion, but I feel that VE.Can's RJ45 connection would be more tolerant of the forces ships undergo than VE.Direct would. There's also the potentially longer cable length and no need to source proprietary cables if & when something fails. :)

Are the connections at the far bottom right power inputs for the PCB?
Does the device accept the same input power voltage range that a typical Victron MPPT handles, that is something between 8 to 76.8 volts?

Hi paltiel,

Nautical environment is a very good use case. It would be possible to use it for a wind turbine or a hydrogenerator.

Ve.CAN support is not planned at the moment, but I can see your point. Something to think about.

Yes. The connection at the bottom right is a power supply input. (10V-70V) At first, we had the plan to power the unit from the turbine only, this turned out to be tricky for configuration and other things.

BR

Hi Markus.

Many thanks for sharing this!
Well, if that is considered a boost, you have one order here if it does what it says ;)
May I ask if this is will be a Victron branded device or your own/something else?
Can you share anything else preliminary in your design and thinking?
One specific I would be extremely interested to learn is what the minimum practical voltage and current required from a turbine to charge a 48V system. A 24V system?
Could you comment on that?
Also curious what the smallest and biggest Victron controller that will work with this?
I would assume by the rating that it might be well matched to work with the SmartSolar MPPT 250/100?.

Exciting times! Many thanks for your work so far!

Hi houser,

Sounds good. Thanks!

Yes, it will be a Victron branded device and therefore compatible with the Victron ecosystem.

"interested to learn is what the minimum practical voltage and current required from a turbine to charge a 48V system. A 24V system?
Could you comment on that?"

Battery charging will be done by the MPPT charger connected to the turbine controller and the battery. Therefore the MPPT rules regarding charging voltages apply.

Vbatt+5V to start charging. Vbatt+1V to keep it going.

It's similar to panels: The higher the turbine Voltage, the lower the current is, to transport the same amount of energy. The turbine might not always be close to the turbine controller/MPPT. So this is a matter of losses (cable sizes).

"what the smallest and biggest Victron controller that will work"

The smallest possible controller will be the smallest available. For the biggest, it will be a 250V MPPT but we have to do maximum continuous power tests. It will also be a matter of enclosure/heatsink. We will see.

BR

houser avatar image houser markus ♦♦ ·

Hello Markus,

Fab! I have a question that i would prefer to ask directly in DM or email.
Could you put an email in here for a minute and then delete it so I could contact you please?

Many thanks

Jan A.

This is very cool. Cant wait to see how this develops.


Is this designed to take the rectified output of your turbine as the DC input? Might be nice to make a companion board with rectifier + brake relay?

Hi hoeken,

yes, it is designed to take the rectified turbine output. A lot of thinking went into the rectifier part. The first prototypes had the rectifier onboard and a lock relay, but it turned out to be the rectifier, that produces most of the heat. We experimented with zero voltage drop rectifiers and in the end, we did it without, to be able to handle larger turbines.

.) there are lots of rectifiers around for a cheap price. It is easier to cool the rectifier when it's an external component.

.) The turbine lock mechanism should come/be certified by the turbine manufacturer. We have an output to drive external locking equipment.

In the end, leaving those parts out, allowed us to design a much more stable and reliable controller.

The first prototype though is perfectly working for over 2 years now.

BR

hoeken avatar image hoeken markus ♦♦ ·
That makes sense. Looking forward to it!
Hi Markus,

Can I get a contact email or number to discuss this project?

Thanks

Ross

ross-mccallum avatar image
ross-mccallum answered ·

Hi Markus,

Interested to get two of these to test.

How can we contact you?

Many thanks,

Ross


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Hi Ross,

thank you very much for your interest.

At this stage, we don't have a "end user operable" firmware.

To change settings, you have to program the unit via serial console commandline.

The prototype units are handmade and at the moment a lot of the electric components have very long(!) shipping time. To use substitute parts, we would have to redesign the circuit a bit.

When we have a stable end user friendly firmware we will for sure need testers with different applications. Also we need to build those units for the tests.

When we are ready to do tests with a larger group of people, I will come back here for sure.

BR

Petr P avatar image Petr P markus ♦♦ ·
Looking forward to test it. Great work, I was been waiting for ut for a while.
Excellent work, looking forward to hearing from you!!
ponzoa avatar image ponzoa markus ♦♦ ·
I would be very keen to be one of your testers (in Madrid). I have, in summary, the following ESS setup;

- Multiplus II 10KVA

- AC Coupled Fronius Primo 8.2-1

- DC Coupled 250/100 MPPT

- Cerbo GX

- 9 x Pylontech US3000C

Looking for wind to suplement the less sunnier months as I have a 16kW heat pump for hot water, central heationg and air conditioning amongst other loads.
I don't have wind yet but have a good place for it with great clearance and as we are in a high altitude place (some 724m amsl), we get great wind when it blows.

I would be willing to share my VRM data.

cpt-pat avatar image
cpt-pat answered ·

Speaking as a retired engineer working with aerodynamics: I don't understand why an MPPT charge controller that is intended to work with a power source (photovoltaics) that actually HAS a maximum power point voltage would be used with a wind turbine generator that does NOT have a maximum power point voltage. It seems you all are giving up a lot of power conversion efficiency and introducing unnecessary complexity just to achieve the administration and metering capabilities of the VE MPPTs. And the power losses of an MPPT controller would be far higher than the miniscule loss of Schottky diodes.

As the airfoils ("blades") on a wind turbine spin faster, more parasite drag is created. The wind-to-power conversion efficiency will be maximum at the lowest rotational speed that will keep the entire foil length unstalled. Any rotational speed above that wastes power. That's why you see a gradual rise in the power curve to a maximal point followed by a saturation plateau with a flatter slope in the velocity to power curve with common fixed-pitch-airfoil turbines. The manufactures will often put some twist in the blades to spread out that curve, but at the sacrifice of optimal performance at intermediate rotational speeds.

All an MPPT photovoltaic controller can do is vary the load on the turbine, which would - once the foils are unstalled - have a detrimental affect on power conversion. Simply routing the output directly to the battery through a diode, that will not present a load until the diode is forward-biased to permit spin-up, would be optimal, provided the airfoils are properly designed. Any other improvement in efficiency would have to occur at the air-to-foil interface: some improvement could be achieved by varying the pitch of the airfoils to remain at an optimal angle-of-attack (here is a description of how that is accomplished: https://www.intechopen.com/chapters/50451), but that algorithm is mechanical and is very different than the behavior of an MPPT controller designed for photovoltaics.

If you want Bluetooth interface capability and good metrics on voltage, power and current, I suggest you try using a Smart Shunt instead and let turbine controllers and MPPT controllers do their separate jobs.

I believe you are trying to make applesauce out of oranges.

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The generator would surely have a maximum power point, it doesn't continue to produce more and more power into infinity.

Why does power increase until a certain RPM and then start to decrease with continuously increasing RPM? Surely the RPM at which the generator is producing its maximum power equates to the maximum power point of the generator?

cpt-pat avatar image cpt-pat wkirby ♦♦ ·

"Why does power increase until a certain RPM and then start to decrease with continuously increasing RPM?"

Drag increases by the cube of the airspeed, while lift (power output) increases by only the square of the airspeed. (A simplified answer without all the calculus.) So as the speed increases, drag overcomes lift and a limit is reached where drag overcomes lift.

Your answer suggests that the power output platau's or levels of as the forces reach equilibrium.

My question was why does the power output of the generator, after a certain RPM, actually decrease with increasing RPM? The power to RPM peak is the maximum power point of the generator, so therefore a generator does have a maximum power point and having this power point tracked would be very useful.

Hi, thank you for your constructive input.


I am far away from being retired, but an engineer.


Could you please try to explain to me, why a PMA generator has no maximum power Voltage.

There are advantages in losses, if there is a higher turbine Voltage than BattV. If you have a higher turbineV, you will need some DC-DC conversion to be done.


Could the MPPT harvest more energy in lower winds?

It is not us, that say: a wind turbine harvests up to 250% more energy when connected to a MPPT. It's Midnite solar, a competitor. We only say it makes sense.

We also want the 3 stage charging. And of course the monitoring.

Best Regards

Markus

@Cpt Pat

I would prefer a conversation instead of following all the edits to your post.

Please explain, why a wind turbine always has the same power Voltage in variable winds.

All an MPPT controller can do is vary the load on the turbine”

This is not the only thing a MPPT can do. It can search for the max. power Voltage. This allows the turbine to spin up more easy and has other advantages too.

By the way: it would be possible to use the turbine controller without a MPPT too. For this, turbineV has to match batteryV and we would need to implement a charging curve to the controllers FW.

PS: I do not question, that a variable turbine geometry would be the best and nicest solution to have. But maybe not that easy to accomplish.

Our turbine controller solution is meant to cover turbines available on the market. The vast majority has fixed blades.

cpt-pat avatar image
cpt-pat answered ·

Reply to all above: Please read the paper below, where achieving a maximum power point was carefully explored. The solution is to use mechanical MPPT variable-pitch airfoils -- not an electronic approach with fixed-pitch airfoils. Trying to use a photovoltaic MPPT controller is reinventing the wheel. It's already been tried -- years ago -- and found to work as well as square wheels. But I'd love to be proved wrong!

https://www.intechopen.com/chapters/50451

And here's a description of a variable-pitch vertical axis wind turbine: https://www.researchgate.net/publication/315040403_Numerical_Analysis_of_Design_Parameters_With_Strong_Influence_on_the_Aerodynamic_Efficiency_of_a_Small-Scale_Self-Pitch_VAWT/figures?lo=1

Yes, if your turbine controller is too primitive to provide the multi-stage outputs (absorb, float, etc.) you need, then you can use an photovoltaic MPPT controller, albeit with all the losses that will entail. But be prepared for all the unfortunate behaviors described in the thread above. The worst being turbine overspeed while the MPPT unloads the turbine seeking the illusory maximum power point. (BTW, if you really want to go that route, to prevent frying the MPPT controller with overvoltage states, I suggest using zener diodes of appropriate ratings across the turbine output to clamp the output voltage to an upper limit. If the MPPT limit is 100 volts, one of these with a heatsink should work fine: https://www.digikey.com/en/products/detail/nte-electronics-inc/NTE5284A/11646599)

What you really need is a controllable variable-pitch impeller to provide that staging. The market should demand that capability instead. Variable-pitch designs also eliminate the need for airfoil twist that trades off coupling efficiency for slow wind speed startup ability.

I'd never try using a photovoltaic MPPT controller on a wind turbine, but those of you who have should try this experiment: configure a DPDT toggle switch to send the turbine output to the MPPT controller or directly to the battery. While measuring the output current in a reasonable amount of wind, switch between the two and see which method: MPPT versus output-direct, produces more power. To be fair, give the MPPT controller time enough to "settle", and then take an honest average of each output because the MPPT controller will be very busy hunting and wasting power while continually running its algorithm.

Personally, I don't need multi-stage charging. I'm using LiFePO4 batteries that do not require absorption or floating. (Does anyone still use lead-acid batteries?) I have 400 AH of LiFePO4 batteries on board my sailboat in a 12 volt bank, and I use a simple voltage/tail current detector to dump the turbine output to a diversion load whenever the terminal voltage reaches 14.2 volts and the tail current drops to 7.5 amps (0.03C). (It's vital to also measure tail current in detecting the end-of-charge threshold!) Charging resumes when the terminal voltage drops to 13.35 volts. It's that simple. A voltage/current sensor and a relay. Done! Complexity is the enemy of reliability. Here's an excellent article on charging LiFePO4 batteries: https://nordkyndesign.com/charging-marine-lithium-battery-banks/.

Anyone who has flown an airplane having a variable-pitch/constant speed propeller knows the advantages: adjusting the pitch provides optimum coupling of power to the airflow with changing airspeeds. The same works in reverse for wind turbines. And to shut it down, you can just feather the airfoils, eliminating all of the loading caused by induced drag, stopping the turbine entirely and providing a much more survivable turbine in high wind conditions.

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I agree, that a variable turbine goemetry would be the best and most efficient way to regulate a wind turbine.

But also the most complicated way.

There vast majority of the turbines available to the market have fixed blades. The goal was to have a solution, to operate those turbines in a Victron system.

Our controller is not “too primitive” to provide a charging curve on the output, but the current firmware can’t do that yet.


Thanks for your input though.

cpt-pat avatar image cpt-pat markus ♦♦ ·

It's too bad variable-pitch constant speed impellers aren't more common. All it takes is a centrifugal governor. The non-gravitational type can be found on some propeller designs. But good luck getting a patent on that. James Watt invented it in 1788.

https://en.wikipedia.org/wiki/Centrifugal_governor

cpt-pat avatar image
cpt-pat answered ·

I looked around, and here is the best yet simplest explanation I found on pitch regulation:

Wind Turbine Aerodynamics: Stall vs Pitch Regulation: https://www.youtube.com/watch?v=Y5T5ZhJQr2o

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