5motor control (mctrl), Stop – Lenze E84DSxxx User Manual
Page 173
Lenze · 8400 protec StateLine · Reference manual · DMS 4.2 EN · 03/2013 · TD05
173
5
Motor control (MCTRL)
5.9
Braking operation/brake energy management
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
5.9.2
Selecting the response to an increase of the DC-bus voltage
If the brake chopper threshold resulting from
is exceeded in the DC bus, the
takes place (use of the brake resistor and/or stop of the ramp function
generator and/or inverter-motor brake).
• Optimum following of the actual speed value until the speed setpoint is reached (e.g. the motor
is stopped rapidly) is always achieved with the help of a brake resistor.
• Stopping the ramp function generator enables smoother deceleration with lower torque
oscillation..
• The inverter motor brake is available for selection in
. This function enables rapid
braking without a brake resistor. Torque oscillations can occur due to the traversing
dynamics.
The way in which the different braking procedures work is demonstrated schematically in the
following illustration:
[5-16] Graph of the effective speed setpoint and the DC bus voltage during braking
Stop!
• The two braking procedures "Stopping of the ramp function generator" and "Inverter
motor brake" can only be used for speed-controlled applications without the
influence of a position controller!
• When the "inverter motor brake" function is used, the
is
not adapted. If it is braked too frequently, there is a risk of the motor being thermally
overloaded or the motor overload monitoring does not work properly!
• The "inverter motor brake" function must not be used with vertical conveyors (hoists)
or with active loads!
Use of the brake resistor (
Stopping of the ramp function generator (
= "1: HlgStop")
Inverter motor brake (
= "3: FI_MotBrk + RfgStop)
n
Set
t
n
Set
t
1
2
n
Set
t
0
t
t
t
U
DC
U
DC
U
DC