Firmware
≤
02.00 - DMS 2.1 EN - 03/2011
L
117
8400 motec | Software Manual
Motor control (MCTRL)
Braking operation/braking energy management
Operating mode of the inverter motor brake
During the deceleration, the speed encoder is stopped. The speed set in
is added to
the speed setpoint by means of a hysteresis-2-point DC-bus voltage controller. Here, the
sign of the current actual speed is considered. Moreover, the speed controller is stopped
during overvoltage.
If the DC-bus voltage falls below a defined DC-bus voltage potential of the hysteresis
controller, the applied additive speed is cancelled and the speed encoder is enabled again.
The alternating acceleration and braking resulting from this circuit cause the energy to be
thermally converted in the motor.
[5-8]
Signal flow of the "inverter motor brake" function
In case of an asynchronous motor the additive speed setpoint (
) is to amount to
the 1 … 4-fold slip of the machine:
[5-9]
Formula for calculating the additive speed setpoint for an asynchronous motor
n
DC-bus voltage
o
Speed setpoint for motor control
0
1
nSpeedSetValue_a
C00105
C00050
C00909/1
C00909/2
C00173
C00174
0
1
QSP
C00987
0
QSP ramp
QSP
p = number of pole pairs
n
rated
= rated motor speed
f
rated
= rated motor frequency
n
Sync
= synchronous motor speed
C00987 [rpm]
1 ... 4 n
Sync
[rpm] n
Rated
[rpm]
–
(
)
⋅
=
n
Sync
[rpm]
f
Rated
Hz 60
⋅
p
--------------------------------
=
Summary of Contents for 8400 motec Series
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