Siemens Sinamics S120 Function Manual page 172

Vector control
4.10 Vdc control
Vdc control with Basic Line Modules
If several Motor Modules are supplied from a non-regenerative infeed unit (e.g. a Basic Line
Module), the Vdc_max control may only be activated for that Motor Module whose drive has
the nominal highest moment of inertia of all connected drives.
For the other Motor Modules this function must be disabled or monitoring must be set.
If the Vdc_max control is active for several Motor Modules, then for an unfavorable
parameterization, the controllers can mutually influence one another negatively. The drives
can become unstable, individual drives can unintentionally accelerate.
• Activating the Vdc_max control:
• Inhibiting the Vdc_max control:
• Activating the Vdc_max monitoring function
Function diagrams (see SINAMICS S120/S150 List Manual)
● 6220 Vdc_max controller and Vdc_min controller
Overview of important parameters (see SINAMICS S120/S150 List Manual)
● p1240[0...n] Vdc controller or Vdc monitoring configuration
● r1242 Vdc_max controller switch-in level
● p1243[0...n] Vdc_max controller dynamic factor (control)
● p1245[0...n] Vdc_min controller switch-in level (kinetic buffering) (control)
● r1246 Vdc_min controller switch-in level (kinetic buffering) (control)
● p1247[0...n] Vdc_min controller dynamic factor (kinetic buffering) (control)
● p1250[0...n] Vdc controller proportional gain (control)
● p1251[0...n] Vdc controller integral time (control)
● p1252[0...n] Vdc controller derivative-action time (control)
● p1254 Vdc_max controller automatic detection ON level (control)
● p1256[0...n] Vdc_min controller response (kinetic buffering) (control)
● p1257[0...n] Vdc_min controller speed threshold (controller)
● r1258 CO: Vdc controller output (ctrl)
170
DANGER
– Vector control: p1240 = 1 (factory setting)
– Servo control: p1240 = 1
– U/f control: p1280 = 1 (factory setting)
– Vector control: p1240 = 0
– Servo control: p1240 = 0 (factory setting)
– U/f control: p1280 = 0
– Vector control: p1240 = 4 or 6
– Servo control: p1240 = 4 or 6
– U/f control: p1280 = 4 or 6
Function Manual, (FH1), 01/2012, 6SL3097-4AB00-0BP2
Drive functions