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Boost Converter/charger feature

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shaman
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Boost Converter/charger feature

The VESC has most things present to achieve boost DC/DC and charging functions. Some controllers on the market feature this. One of the motor phases could be used as an inductor or even an external inductor could be used. 

the way that it could work: disconnect a phase leads so you have access to the H-bridge

battery stays connected in the same way as if it were a motor controller.



on the the phase leads input your power supply(Ud) with caps (Cd) in parallel and inductor (L) in series. (referenced to BAT-)

Uo is the battery.

T1 is the bottom switch T2 is top switch

Image

vadicus
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Voting for this feature. It seems like VESC has ALL it takes to run a DC/DC booster. I would like to add it to my custom 150v controller.  Ideally, without having to disconnect anything to get into charge mode. Just plug in the DC source.

Now, the "easy" part: Implement it in the software. It would makes sense to add it as an "app" module similar to ADC or IMU modules.

Looking up some examples for the code, it does look pretty simple. Some example from here https://www.electronoobs.com/eng_circuitos_tut10_1.php

/*

 * This is an example code for a BOOST converter circuit made with arduino + feedback

 * I've used arduino NANO. We have to set the timer of the PWM on pin D3

 * The feedback is connected to A1 and we set the desired voltage with a

 * potnetiometer connected to A0.

 * 

 */

 

int potentiometer = A0; //The input from the potentiometer is A0

int feedback = A1;      //The feedback input is A1

int PWM = 3;            //Digital pin D3 por PWM signal

int pwm = 0;            //Initial value of PWM width

void setup() {

  pinMode(potentiometer, INPUT);

  pinMode(feedback, INPUT);

  pinMode(PWM, OUTPUT);  

  TCCR2B = TCCR2B & B11111000 | B00000001;    // pin 3 and 11 PWM frequency of 31372.55 Hz

}

void loop() {  

  float voltage = analogRead(potentiometer);    //We read the value of the potentiometer, which is the desired value

  float output  = analogRead(feedback);         //We read the feedback, which is the real value

  //If the desired value is HIGHER than the real value, we increase PWM width

  if (voltage > output)

   {

    pwm = pwm+1;

    pwm = constrain(pwm, 1, 254);

   }

   

  //If the desired value is LOWER than the real value, we decreaase PWM width

  if (voltage < output)

   {

    pwm = pwm-1;

    pwm = constrain(pwm, 1, 254);

   }

   analogWrite(PWM,pwm);  //Finally, we create the PWM signal

}

 

 

NextGen FOC High voltage 144v/34s, 30kw (https://vesc-project.com/node/1477)

TechAUmNu
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Would be a cool feature to have a DC/DC supply app, so you can just set what voltage/current you want. VESC already operates as a big buck converter and you can use it to run constant current through high power LEDs, or provide a high current constant voltage power supply. The control loop is quite slow and pwm speed doesn't make it great for anything fast though. 

frankus
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+1. It would be pretty cool to be able to charge with one of those pocket-sized 100W GaN chargers or your buddy's MacBook charger. They max out at 20V @ 5A, so being able to boost back up to battery voltage is key. 

jacopo
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Hi guys, is there already someone working on it or should I start modifying the firmware (and maybe the board) from scratch?

A-damW
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Maybe ya'll have seen this: https://github.com/vedderb/vesc_tool/issues/141

vedderb himself: https://github.com/vedderb/vesc_tool/issues/141#issuecomment-854424882

I suppose you could set up two profiles in the phone app, one for charging, and one for motation.

Svein Utne
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Hi, I am new to this site, and I started looking at SimpleFOC for Arduino, but they do not have regen yet, something I need. My plan is to rebuild my sailboat to use electric motor and batteries instead of the diesel engine. When I am at sail I hope to regen some watts back into the batteries. The electric motor came from an early Think (Pivco) with only 12 KW motor. 100 volts and 100 amp. The Trampa controller VESC 100/250 might be good for this. It would have been nice if it could take 110 volts, but I can reduce the batteries down to 95 volts to be on the safe side.

What I wonder about is how good the regen is. When I am sailing the propeller will turn much slower, so the voltage from the motor might be too low to be able to generate the batteries?

So my question is: Will VESC 100/250 be able to put energy back to the batteries when the propeller only turns at 500 rpm? 

I have an alternative solution if the VESC cannot to do it, and that is to use a DC-DC booster I got, but then I also need to disconnect the VESC from the battery, and connect it to the booster.

Any thoughts on this?

Regards

Svein Utne

PS. This was first posted at: VESC-Project Open Source status? but I am not sure where this sort of discussion is right.

vadicus
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SimpleFOC is a fantastic project mostly due to great portability potential, and I hope it will evolve into something close to VESC in functionality/features. It's just very basic at the moment (hence simpleFOC I guess), but it needs at least BEMF sensing for power applications.

Higher voltage will mean better efficiencies most of the time as you would not have to run higher amps for the same amount of power, and higher current means more heat (I2R) losses. Bonus, the charging will be faster and more effecient as well.

Regarding regen, 500rpm is not exactly that low. The controller is basically a buck-boost converter, you would still be producing your set voltage at very low RPMs. My bike has a direct drive motor and a 109v battery pack. I can regen by pushing it slowly at like 3mph and get current pushed back to the battery. I am probably spinning the motor at 100rpm or so.

It's unlikely you will have a meaningfully better efficiencies with a dedicated booster vs. the controller. I would say it's not worth the trouble of manually switching back and forth. I would spend more time understanding the best efficiency range for the motor and adjust the prop size and/or gearing, so it ends up operating in that effecient RPM range most of the time (this is usually the cruising speed).  

 

 

 

 

NextGen FOC High voltage 144v/34s, 30kw (https://vesc-project.com/node/1477)

Svein Utne
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Thank you Vadicus for your incite. I have been looking at how to install the DC-DC booster, but it is not easy, so if the VESC really can lift the regen voltage up to 100v at only 300-500 rpm it will make everything much better.

vadicus
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A "regular" DC-DC boost converter simply boosts a certain direct current source (two wires - positve and negative) to a higher voltage. I am guessing you are dealing with a three phase motor which means alternating current, three phases. You cannot attach a DC-DC boost converter to a three phase motor and expect this to work. You need a three phase converter which is what a controller such as vesc is when it operates in regen mode. Put it simple a DC-DC converter is not the right solution. Additionally, you really,really don't want to run any controller with 100v rated components right at at 100v. You may get lucky to run it at this extreme for sometime but the system will be unreliable and will likely fail soon. You absolutely need to have a safety margin. That means a 100v controller should be run at 90-95 absolute max voltage but lower is better. 

 

 

NextGen FOC High voltage 144v/34s, 30kw (https://vesc-project.com/node/1477)

Svein Utne
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vadicus, you are so right. What I have been looking for was a ESC that could handle 120V and 100A. I see you have made a esc for 144V and plenty of amps.

What is the status of your  project? are you selling finished products? what is the price?

vadicus
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Yes, controllers have been working great, lots of unique features. Currently working to release a wireless touch display: https://vesc-project.com/node/3950

 

 

NextGen FOC High voltage 144v/34s, 30kw (https://vesc-project.com/node/1477)