Moto Profiler does not reach maximum engine speed.

[OttoBCN]

Hi, I am using ST Motor Pilot Tool (profiler) V1.2.9.
With the B-G431-ESC1 plate and the A2212/13T motor (technical sheet attached).
I can't get the motor above 5200 RPM. Please note that to get to 5200 rpm I had to increase the overvoltage to 80% because otherwise I would get an overvoltage error.

How can I get the engine to reach 10Krpm?

Is it normal to increase the over voltage so much?

Thank you very much for your time and support.

[OttoBCN]

I have been trying to increase the supply voltage.
Achieving an increase in engine speed.

 

I understand that for a 10V motor the supply voltage will have to be double (20V).
In order to generate positive (10V) and negative (-10V) voltages.

So in the motor section (electrical parameters), in Max DC Voltage, do I have to enter the value of the Nominal Voltage or the Nominal Voltage*2?

[OttoBCN]

He estado intentando aumentar el voltaje de suministro.
Logrando un aumento en la velocidad del motor.

 

Entiendo que para un motor de 10V la tensión de alimentación tendrá que ser el doble (20V).
Para generar voltajes positivos (10V) y negativos (-10V).

Entonces en la sección del motor (parámetros eléctricos), en Voltaje Máx. DC, ¿tengo que ingresar el valor del Voltaje Nominal o el Voltaje Nominal*2?

[Gael A]

Hello OttoBCN,

First of all, for a 10V BLDC motor, the input Bus Voltage has to be the same (so 10V and not 20V). The sign of the voltage value only depends on the direction of the sensing. Ultimately, only 10V is needed. Be aware that you may have damaged your motor by increasing the input voltage higher than the motor's datasheet.

Secondly, the Profiler does not need to reach max speed for you to have correct constant values. Even if max speed is not reached, Rs, Ls, friction and inertia values are correct and can be used as is. You can save your .json file and modify manually your max speed value if need be.
Once your motor is profiled, you can create a new project using your brand new motor description. You will then be able to fine tune this project to get the maximum speed from your motor.

[OttoBCN]

Thanks for your answer.
I have followed your instructions and generated the project. I've been testing it and I can't reach 10Krpm.
How can I adjust the project to increase the engine speed?

The engine has not been damaged, it has not even warmed up.
Thanks for your time.

 

[Gael A]

Hello OttoBCN,

From what I can see, your PWM frequency seems a bit low. Let me explain :
You wish to run at 10 000rpm, which gives roughly 10 000 / 60 = 167 Hz (mechanical). I see that you have a 14 pole pair motor, that would give an electrical speed of 167 * 14 = 2 333 Hz.

When using our standard FOC library, we recommend the user to get at least 10 sampling per rotation, thus giving you a recommended PWM frequency of 2 333 * 10 = 23 330 Hz.

You can make a try at 24kHz or even 25kHz and see how that goes.

[Gael A · Accepted solution]

Hello again OttoBCN,

There is something else that may be at cause here. Looking at your motor's datasheet, we can see that there are 14 Poles. Strictly speaking, that would mean 7 Pole Pairs. In that case, 16kHz PWM would do the trick and your motor may already run at 10 krpm, but the Pilot / Profiler would be showing a 2 times lower value.

Thus, could you verify manually how many pole pairs your motor has exactly ? Don't hesitate to use the dedicated Profiler feature for doing so.

[OttoBCN]

You were right. There are 7 pairs of poles.
Thank you for your support and your time dedicated.

You are a great help.

Soon I will do more tests and more questions.