How to gain maximum energy from any wind turbine at every wind

Biggest sin is greed. When we want to take more energy from turbine than wind can give us at given speed turbine brakes and finally stops.
Energy of wind at any given wind speed is easy to calculate but… when we dont know what is our wind speed and we do not know how much energy can our wind turbine produce?
Because lets be honest there are many producers who rely on it and simply cheating in their tech specifications
How to calculate it?
Lets make the first assumption of our discussion: we will focus only on those turbines that have a chance of producing electricity
Which means 3blade Horizontal wind turbines. All this magical and make believe design are only for decoration anyway.

Deadly sin of wind turbine controllers

Harsh truth : wind turbine is a little bit like free energy generator from Indian yt videos.
Could be total scam
for a moment it will give off energy received from the inertia of the rotating masses . which means that if wind speed lets turbine to produce 1kw of power and our controller loads the turbine with a power of 1.2kW turbine will give off 1,2kw for few seconds and then it will stop. Which is difficult if not impossible for the controller to distinguish from a situation where the wind speed has temporarily decreased.
And this is used by by dishonest producers to artificially inflate turbine max power
They know its very hard to prove it in court and even if they scammed you of 10 or 20 thousands proving youve been scammed could be even more expensive.

And We have solution!

1. As an industry standard for onshore wind turbines Rated power is always at 15m/s wind
2. Rated power is power wind turbine can provide for at least 120s continuously

But all that means we still need to buy an installation and pay the money before we can assess whether it is a good wind turbine or scam?

Aerodynamics comes to the rescue

There is fixed tip to wind speed ratio for 3blade turbines
Depending on design it is between 5 and 6. Which means that for winds between 3 and 15m/s blade tip is always roughly 5times faster than wind

Or should be! There are some poorly designed turbines like ista breeze but for all decent wind turbines this is the truth

What can we do with it?
We can check turbine alternator before even buying it and we can use deye wind power input correctly
For example we are using 4m diameter wind turbine. Producer or dealer tells us it is 5kW rated power.
First what we can do is calculate swept area and calculate weather this power is at all achievable for any turbine with this diameter blades
If we would have ideal blades each 1msq of swept area could give us 820W of power so if we have 4m diameter and swept area is Pi*R2
So R is half of diameter 3.14×4= 12,5sqm. This turbine has potential to give us 10kw power if it would have really good blades.

But only potential how can we check if it lives up to it?
We know tip ratio should be between 5 and 6 and rated power is at 15m/s
So tip speed is 75-90 m/s
Then distance for every rotation is 2 Pi*R where R is half of our diameter so our tip is going for 6,28×2 which is 12,5m per every rotation
So we can calculate rpm of our wind turbine at 15m/s at the wind of maximum power!
Every second our tip is making 75m at least so if one rotation is distance of 12,5m this means that our blade makes 75/12.5= 6 rotation
Rpm is rotations per minute so 6 rotations per second times 60seconds is 360RPM for maximum power!!!

We can use lathe and spin turbine shaft to this rotations and measure if it can really give this amount of power!
what if we don’t have a lathe powerful enough to drive the turbine to such speeds?

Most important we can ask producer/dealer to provide us with this easily verifiable data as voltage and power generated by turbine alternator at given RPM

Second especially with smaller wind turbines we can use drill and few inches of gardening hose to spin our turbine and at least read voltage!

And this is even more important
Why? Biggest problem with small-cheap wind turbines is controller. In this systems for the sake of economy we almost never use anemometers so only thing which can be measured by controller are rotations.
But it almost never is. It is too troublesome because different generators will have different wiring so frequency from generator could be different for the same wind.
But… generator has one great feature: the higher the rpm the higher the voltage
Soo we can assume rpm just by measuring voltage

I prepared below table which you can send to turbine supplier to fill voltage for your specific rpms

Most of generators today are 3phase PMG so there is this strange regularity
Open circuit ac voltage is equal or close to equal to DC voltage under load

So we need to measure only