2011-12-07 02:00 AM
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 (
fourquadrant)
?
At
the documentation
the motor
is always
in wye connection.
Isthe library
prepared
to control a motor at delta configuration?
Would it change
the parameters
Rs
and
Ls
used by the
software ''
workbenchst
motor control
''? And another parameters?Best regards
2011-12-09 08:38 AM
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 Gigi2011-12-12 01:27 AM
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
2011-12-19 08:35 AM
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