Bldc motor heats up rapidly..

[Nihaludeen]

I am driving a 1KW bldc motor (CYM-A1-120) using my bldc inverter. And i am not sure the frequency of motor, So i constantly run at 7Khz. The motor runs fine with a little noise. The temperature of the motor gradually increases.,

(i,e) the room temperature =30 degree C
the motor temperature at 0 min = 30 degree C
the motor temperature at 15 min = 45 degree C

- I am driving the motor at 48 v and 2 amp (no load).
- I am not sure about this temperature is ok for a motor or its too hot.
- Nominally what will be the temperature (at 48 v and 2 amp).
- Or my bldc inverter is working unlike

Guide me if i am wrong...

 

[KlausST]

Hi,

Guide me..

What I'd do: read the datasheet.
This is the one source of information you can rely.

My taste: 45°C should be no problem for the motor. But you should be aware that the coil will be (much) hotter than the motor case.

Klaus

 

[Nihaludeen]

Hi,



What I'd do: read the datasheet.
This is the one source of information you can rely.

My taste: 45°C should be no problem for the motor. But you should be aware that the coil will be (much) hotter than the motor case.

Klaus

Just now i am tested the motor with my controller once again for one hour at 48 v and 2.5 amp (no load)...
The measured result is...

min..... motor temperature in degree C
0...... 30
5...... 43
10..... 50
20..... 55
35..... 57.5
50..... 58.5
60..... 59

For the first 20 min it reaches 55C fast and after it slowly increases.
I am not sure whether this type of heating is correct or good for 1Kw bldc motor at no load (2.5amp)

 

[BradtheRad]

i am not sure the frequency of motor, So i constantly run at 7Khz.
...
no load

Your switching frequency calculates to rpm in the realm of 100,000 rpm.
I imagine a reasonable rpm is 1800 rpm. Suppose your motor has 3 magnets and 3 coils, then it implies switching at 90 Hz.
With no load you can apply a narrow duty cycle, and the coils will draw less power and won't heat up so much.
Send brief pulses to the coils.

You need to begin a pulse at a time when magnets are approaching close to the coils, so that the attractive force does the most good.

Turn off an attraction pulse immediately as the magnet is at nearest approach to the coil. Or else change to a brief repelling pulse.

As you attach a load to the motor, you'll need to give it more power by increasing duty cycle, that is, by lengthening pulses.

 

[Nihaludeen]

Yes i have driving the motor by correct commutation state, the controller is good.But motor is getting hot as i mention above.

 

[Easy peasy]

Sounds like a quality motor (not)

 

[KlausST]

Hi,

Without detailed informations we can´t give good answers.

Yes i have driving the motor by correct commutation state

--> what is your communtaion scheme?

the controller is good

--> Which controller with which setup?

I am driving the motor at 48 v and 2 amp (no load).

-->What is this current? DC, or AC RMS? Measured at the 24V DC bus or at one of the motor wires? If so, what phase shift?

*****

by correct commutation state, the controller is good

You tell us assume that everthing is correct ... but obviously there is not everything correct, and we are not able to verify your informations.
--> give us "objective" informations, like schematics, code, photos...

Klaus