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Maximum Reverse Power Output for Power Generation

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Tobias Kornmayer
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Maximum Reverse Power Output for Power Generation

For using VESC in wind and water turbines, I would like to suggest a FOC algorithm which maximizes power output into the battery. From there a standard grid tied micro inverter can pickup the power and feed it to the grid. The algorithm would also increase or decrease the rotation frequency depending on whatever generates more power.

Or is this kind of control is better done by a standalone controller which talks to the vesc? The big advantage of running directly on the vesc would be the near realtime execution.

frank
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The STM chip has headroom to run additional computations, so it's probably best to run it on the VESC as long as there is enough headroom for this kind of computation.

Such software changes are a matter of available resources and need to be debated. Basically you want to compute the perfect torque resistance to output the max. power into the grid?

Frank

benjamin
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Sounds like an interesting project. You are probably looking for MPPT. I think this feature is a bit too specific to be included in the main code base, but it should be quite straight forward to make a custom application for it.

Roger Wolff
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Running on the VESC itself would with some effort allow a tenth of a milisecond response time. 1 or 2 ms response time is simple: The ADC app does that too.

 

But this is way too fast for such an MPP tracker; You have tens, hundreds of thousands of miliseconds worth of energy stored in the rotor So when you increase the reverse torque, you will always (temporarily) increase power output because you are extracting energy from the rotor. So the control loop will have to be much slower than that. Doing something at a leasurly pace, on a separate, quick-to-reprogram CPU may be a good idea to work on optimizing the algorithms. You can easily request power numbers through the UART from an arduino for example. Then later integrating into an app on the VESC once you know the algorthm to use. 

rodread
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I'm going to try something similar. Using the VESC to control charge from a kite turbine.

The turbine is geared to a 350rpm 36V 500W Brushless Gearless Hub Motor Motor 5.5kgs Diameter: 24.5cm Hall Sensor Quantity: 3pcs Max. Speed: 350RPM Max. Torque: 24.5N.M Magnet Body Size: 300*136*30mm Axle Diameter: 1.5cm Bushing Size: Diameter: 1.5cm, Height: 3.5cm Min. Fork Width Requirement: Min.10cm Corresponding Controller: 36V 500W Controller Disc Brake Available: 6-hole type 

The main purpose is eventually charging an e-car. I'm going to try give a small part charge to an e-car (massive charge by normal standards 3.5kW scary!) through a large inverter 36VDC 5000W pure sine wave to an e-car granny charge cable (3.5kW).

I'm planning to use the VESC to charge a 10S Lipo (5 x Turnigy 5000mAh 2S 7.4V 60C Hardcase Pack) which is small compared to a car battery of course, this is only a part charge for the car.

I reckon I have to derive a control setup on an arduino or other which looks at  VESC RPM data and trys to keep the motor/generator running consistently faster to achieve the 42V max charging a 10S BMS set needs. (such as this one ... http://bestechpower.com/37v10spcmbmspcbforli-ionli-polymerbatterypack/PC... )

(Would be nice if I could simplify by plug VESC straight into car DC to charge or Just turn the car wheel with my kite turbine for regen )

Looking forward to experimenting. Thanks for VESC environment. My kite turbine hardware is open source too if you want to play with one.

The kite turbine builder

rodread
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After running a few bench tests with the VESC6 - I love the interface and walk through nature of VESCtool software.

However I don't yet know how to get the best configuration for regen control.

Ideally for me ... At zero speed there's zero braking for regen,  as things speed up I'd apply more regen up to a max, say 600W

At the moment Using ADC & UART with ADC set to Current No Reverse Brake ADC2. I set ADC2 to give me a good braking resistance for generating. 
However: After I stop turning a large spike in current resists any more turning. How can I stop that happening? I really only want to set a braking resistance and no Handbrake.

screenshot https://drive.google.com/file/d/1YpZbfC5i1378ikyMPUSrZQ5G6zRmhnW2/view?usp=sharing

Any advice on where I should read up on configuring for regen, or how best to start really diving into the code would be very welcome thanks.

 

The kite turbine builder

SaqibBajwa
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Hi guys,

I am also trying to do something very similar to 'rodread'. Can anyone please suggest the best configuration settings for both Motor and App parameters for a ADC controlled brake resistance/current? 

Thanks a lot in advance.

SB