STM32 FOC PMSM SDKv3.0 decelerating a motor

[IHS1]

Posted on December 07, 2011 at 11:00

Hello

I

need to

decelerate

a motor on

a closed loop

speed

(no

braking

free).

The system

should reduce the

duty cycle

and finally implement

a change of

quadrant

motor.

Is

the library

prepared

to decelerate 

the motor

in closed loop (

four

quadrant)

?

At

the documentation

the motor

is always

in wye connection.

Is

the library

prepared

to control a motor at delta configuration?

Would it change

the parameters

Rs

and

Ls

used by the

software ''

workbench

st

motor control

''?

And another parameters?

Best regards

[Gigi]

Posted on December 09, 2011 at 17:38

For sure the STM32 FOC library can be used to impose a negative torque and so, to brake the motor in a controlled way.

You need to take care of course of the regenerative power. The library is also able to detect an over voltage condition and acts short circuiting the motor phases or driving an external brake resistor. And in case of sensorless the problem is the reliability of the algirithm for low motor speeds.

Finally I have no experience on delta configuration.

Ciao

Gigi

[IHS1]

Posted on December 12, 2011 at 10:27

Hi.

Thank you for answering

so quickly.

Well, if

anyone is interested

.

I searched the

web

and in respect of

the motor

in delta

connection

.

I've seen

you do

a

conversion

of the

impedance

parameters

R and

L.

From

wiki:

Δ

-Y

transform.

R_1

= (

R_b

*

R_C

} (

R_a

+

 

R_C+

R_b

}

R_2

= (

R_a

*

R_C

)}

+

R_C

+

R_b+

R_a

 )

R_3

= (

R_a

*

R_b

) (

R_a

+

 

R_C

+

R_b

)

Although

set

R

are

impedances.

I have

not yet

clear whether

Ke

it is necessary to

adapt

.

best regards

[bille.stello]

Posted on December 19, 2011 at 17:35

Hello Jokin,

in my opinio you may not care whether your motor is star or delta connected.

In fact, if it is delta connected, you can alway think to its equivalent star connected...

So for my you can just measure the resistance line-to-line and asses the phase resistance (of the equivalent motor star connected) is half to the resistance measured this way.

Of course same reasoning can be done for all the others parameters..

Best Regards,

billino