Compound Braking - Siemens SINAMICS V20 Operating Instructions Manual

Commissioning
5.6 Function commissioning

Compound braking

For compound braking (enabled using P1236), DC braking is superimposed with
regenerative braking (where the inverter regenerates into the DC-link supply as it brakes
along a ramp). Effective braking is obtained without having to use additional components by
optimizing the ramp-down time (P1121 for OFF1 or when braking from f1 to f2, P1135 for
OFF3) and using compound braking P1236.
Setting parameters
Parameter Function
P1236[0...2] Compound braking current [%]
P1254 Auto detect Vdc switch-on levels
94
Setting
This parameter defines DC level superimposed on AC wave-
form after exceeding DC-link voltage threshold of compound
braking. The value is entered in [%] relative to rated motor
current (P0305).
Range: 0 to 250 (factory default: 0)
This parameter enables / disables auto-detection of switch-on
levels for Vdc_max controller.
= 0: Disabled
= 1: Enabled (factory default)
It is recommended to set P1254 = 1 (auto detection of Vdc
switch-on levels enabled). Note that auto detection only works
when the inverter has been in standby for over 20s.
Operating Instructions, 09/2014, A5E34559884
SINAMICS V20 Inverter