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Speed Control for BLDC-PMSM

Forum 1
(@abdul)
Active Member

Hi,

I am new to SOLO and I'm using this motor

I have just started working with SOLO and I started with digital control using the motion terminal. I followed the tutorial in this link with BLDC-PMSM ultrafast with PWM frequency of (80K). When I follow exactly the same steps, the motor is not moving, the power reference % value in the video is 0. However, when I change the power reference [%] from "0%" to e.g. "50%" the motor starts to move.

Is the power reference supposed to be zero?
Is there a specific value for the magnetization current or does it depend on the motor? because the motor data sheet did not specify this value.

 

am I missing something?

 

Cheers 

Quote
Topic starter Posted : 19/05/2021 10:51 am
SOLO Team
(@milad)
Chief Member Moderator

Hi @abdul,

to start with your question, first of all, the video you put as your reference is for AC induction motors and they are different from what you need, to proceed pls watch this video which explains how to control the Speed of your Brushless motor in the sensorless mode in analog mode, just notice, it seems your motor is from "Ultrafast BLDC-PMSM" types, so you can watch that video from 17.00 which talks about the ultrafast motors.

The article that talks about the same video is also here, so you can see what was the wiring in that case:

https://www.solomotorcontrollers.com/control-speed-brushless-motor-manually-closed-loop-sensorless-mode/

Posted by: @abdul

Is the power reference supposed to be zero?

Actually, Power reference is only used when you use SOLO in Open-loop mode ( PIN No# 5  in Piano Switch is UP), however, it's much better if you try to put SOLO in Closed-Loop Mode( Put PIN No# 5  in Piano Switch Down), and then controlling the Speed of your Motor.

If you are using the Motion terminal, I recommend you also watch this video to learn how you can do the speed control in Digital Mode ( in your case sensorless mode)

To learn more about Motion Terminal and how to control a motor using that you can also read the following article:

https://www.solomotorcontrollers.com/setup-tune-motors-using-solo-motion-terminal/

Let us know if you have other issues, we will remain available.

Regards
Milad

 

If you found the answers helpful and you could solve your problems, please kindly verify here to help others in the future.

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Posted : 19/05/2021 12:08 pm
Forum 1
(@abdul)
Active Member

Hi @milad

 

Thanks for your reply.

 

I have taken the time to test the motor with SOLO now. After I read all the relevant articles and watched the videos you suggested for Ultrafast BLDC-PMSM and the video tutorial for motion terminal, I followed every thing to the letter, but I failed to operate the motor.  I will explain what I did in detail below

Details of my Motor:

Maximum input voltage

32V

Maximum current

88A

KV

1500

No load current

1.8A

 

 

Set up of my DC Power supply

Voltage

30V

current limited to

10A

 

Using Analogue Connection in Sensorless operation:

  1. I connected the motor with SOLO as shown here.
  2. PIN #4 was down for speed control mode.
  3. Then I put PIN #5 down for motor identification. All other piano switches are up.
  4. The KP and KI was fully C.C.W.
  5. Current limiter potential was half-way.
  6. Speed potential was down i.e. refence speed is 0rpm
  7. I slightly increase Kp and increase the speed potential [ at this point there is still no rotation, but when I increase the speed potential I can here noise/small movement from the motor and it draw higher current from the supply, again no rotation].

After many trails with the Kp and Ki tuning the motor is still not rotating.

  1. I increase the current limiter potential (i.e. it allow for the maximum current SOLO can support), I can only here a noise with small movement but not rotation.     

Using motion terminal:

  1. Connecting SOLO with motor and the PC as explained here, with piano switch no5 is down for closed loop operation.
  2. I powered up SOLO.
  3. Open motion terminal and chose digital mode with sensor less operation.
  4. I choose the correct motor configurations of the motor [ 4 poles, BLDC-PSPM ultrafast, 80K Hz, current limit = 20A]
  5. I press motor identification – at this stage the motor rotate/move for 2 sec.
  6. Now I moved on to set the control loop, I choose [torque control, sensor less ,digital mode]  
  7. I set Iq to 2A and the motor did not move. Then I tried to increase the value s of Iq (up to 20A) but the motor did not really move. If I put very high value of the current, the motor make noise with no movement and the power supply draw high current.
  8. Please note that the speed control was not working i.e. if I set the reference speed to any speed value the motor is motor moving even at different value of Kp and Ki.
  9. At this stage, I thought that I might need to tune torque loop gains, so I followed your tutorial on how to tune the motor. I tried to tune observer, filter and current gains for the chosen motor but it did not really help.
  10. I spent a couple of weeks trying to get this working but with no success, I also tried to use different value of PWM frequency, motor type, current limit with no success!

 

 

 

Did I miss any step?

 

Soon I will try the sensored mode and see if the situation change!

This post was modified 2 weeks ago by Abdul
ReplyQuote
Topic starter Posted : 10/06/2021 10:27 am
SOLO Team
(@milad)
Chief Member Moderator

Hi @abdul,

Posted by: @abdul

Current limiter potential was half-way.

for the first tests to make sure this one is not making any issues, you can totally not mount the current limit Potentiometer and leave the "P/F" input open, in this case the current will be at max, and it will be fine for your Motor.

Posted by: @abdul

The KP and KI was fully C.C.W.

This is not good, first put the Potentiometers fully C.W to make sure they are at zero, then increase like 10 Degrees only the Kp, and see if the Motor starts to Move, if you increase these gains dramatically, your Motor will be unstable.

Other questions and points:

Posted by: @abdul

I choose the correct motor configurations of the motor [ 4 poles, BLDC-PSPM ultrafast, 80K Hz, current limit = 20A]

1) In Motion Terminal, how do you set the values? you must press Enter or push the Set button, and then read the value to make sure it's already set

2) what is the Firmware version you're reading in Motion Terminal?

3) are you sure in Motion Terminal the "Speed/Torque Control Mode*" is set on Sensorless? ( the best is you do a reset factory, just press the reset factory button while SOLO is ON, then Turn it Off, Wait 5 second, and then start your new set of tests)

it will be great if you send me a photo of your Setup + the Motion Terminal Screenshot, I will be available.

Regards

Milad

 

If you found the answers helpful and you could solve your problems, please kindly verify here to help others in the future.

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Posted : 10/06/2021 10:53 am
SOLO Team
(@milad)
Chief Member Moderator

Hi @abdul, just wanted to know if you could solve the issues or if anything changed since our last discussion?

Regards

Milad

 

If you found the answers helpful and you could solve your problems, please kindly verify here to help others in the future.

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Posted : 14/06/2021 12:52 pm
Forum 1
(@abdul)
Active Member

Hi @milad,

Sorry for the late  reply. Actually I wasn't able to get the sensorless mode working neither in analogue nor digital mode. I have attached a photo of my setup.

 

Therefore, I had to move on to sensred mode, I connected and calibrated the hall sensor following your guide I was able to get the motor to work just find.

  

ReplyQuote
Topic starter Posted : 15/06/2021 2:31 pm
Forum 1
(@abdul)
Active Member

here is motor terminal connection 

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Topic starter Posted : 15/06/2021 2:32 pm
Forum 1
(@abdul)
Active Member
Posted by: @milad

This is not good, first put the Potentiometers fully C.W to make sure they are at zero, then increase like 10 Degrees only the Kp, and see if the Motor starts to Move, if you increase these gains dramatically, your Motor will be unstable.

Sorry I meant to say fully C.W

ReplyQuote
Topic starter Posted : 15/06/2021 2:34 pm
SOLO Team
(@milad)
Chief Member Moderator

Hi @abdul,

Thanks for answering back

Posted by: @abdul

I wasn't able to get the sensorless mode working neither in analogue nor digital mode. I have attached a photo of my setup.

Ok, that's something we can work on it depending on your preferences, as you say now in Sensored Mode, you are running SOLO and your Motor, so if you want we can go deeper in sensorless later, but in both cases, we should be able to run your Motor, of course in sensor-based applications, the accuracy of speed control will be better, but still I'm confident the sensorless mode should work too.

Posted by: @abdul

Therefore, I had to move on to sensred mode, I connected and calibrated the hall sensor following your guide I was able to get the motor to work just find.

good, it will be great if you provide some more information like:

  1. What is the Min-Max speed you are going to achieve
  2. What is the speed range you achieved in sensor-based Mode? ( I imagine using Hall sensors)

Regards

Milad

 

If you found the answers helpful and you could solve your problems, please kindly verify here to help others in the future.

ReplyQuote
Posted : 15/06/2021 2:38 pm
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