Armature Short-Circuit Braking, Dc Braking - Siemens Sinamics S120 Function Manual

Basic functions

6.10 Armature short-circuit braking, DC braking

Overview of important parameters (see SINAMICS S120/S150 List Manual)
● r0863 CO/BO: Drive coupling status word/control word
● p1206[0...9] faults without automatic restart
● p1207 BI: Automatic restart (AR) - connection to the following drive object
● p1208 BI: Automatic restart - infeed fault
● p1210 Automatic restart, mode
● p1211 Automatic restart, attempts to start
● p1212 Automatic restart, delay time start attempts
● p1213 Automatic restart, waiting time increment
X_INF stands for all drive objects "Infeed"; i.e.: A_INF, B_INF, S_INF
1)
6.10 Armature short-circuit braking, DC braking
Armature short-circuit braking or DC braking can be set using parameters p1231[0..n]. The
current status of the armature short-circuit braking or the DC braking can be seen in r1239.
Armature short-circuit braking
Using this function, you can brake permanent-magnet synchronous motors. The stator
windings of synchronous motors are then short-circuited. For a rotating synchronous motor,
a current flows that brakes the motor.
Armature short-circuit braking is preferably used when
● braking should be realized without energy recovery
● the drive should be braked when the power fails
● an infeed unit is used that is not capable of energy recovery
● for orientation loss, e.g. in the event of an encoder fault, the motor should still be braked.
You can switch the armature short-circuit braking internally via the Motor Module or
externally using a contactor circuit with braking resistors.
The advantage of armature short-circuit braking over a mechanical brake is the response
time of the internal armature short-circuit braking with just a few milliseconds. The response
time of a mechanical brake is about 40 ms. For external armature short-circuit braking, the
slowness of the switching contactor results in a response time of over 60 ms.
DC braking
Using this function, you can brake induction motors down to standstill. With DC braking, a
DC current is impressed in the stator windings of the induction motor.
DC braking is preferred in the event of danger, when
248
Function Manual, (FH1), 01/2012, 6SL3097-4AB00-0BP2
Drive functions