Operation
7.11 Closed-loop control
SINAMICS DCP
Operating Instructions, 09/2019, A5E34382853K
343
internal resistance of a connected (capacitive) load.
To do this, the load internal resistance must be known and set in p55515 (side 1) or
p55516 (side 2).
The internal resistance must be specified referred to the reference resistance:
Reference resistance = reference voltage (r50071) / reference current (r50072).
The following reference resistance for the device versions is obtained:
– 30 kW-DCP: 600 V / 50 A = 12 Ω
– 120 kW-DCP: 600 V / 200 A = 3 Ω
Figure 7-74 Internal voltage of a voltage source
In addition, the assignment of the DCP sides to the voltage control can be interchanged
using p54104.
Switchover is possible in operation; however, it should only be done under specific
conditions:
– Approximately the same voltage is available at side 1 and side 2 or
– the voltage setpoint is correspondingly set to the new voltage actual value at the
instant of switchover.
This means that undesirable equalization responses of the voltage controller can be
avoided.
● Rate/delay time in the actual value channel (p54121, p54122):
This element is used to improve the control dynamic response by increasing the phase
response or reducing the amplitude response in certain frequency ranges.
In the factory setting, the voltage controller is optimized for compensating disturbances.
This is simplified using the D component (p54121, p54122) in the actual value channel.
The control response can be optimized; to do this, the D component must either be
reduced or deactivated.
● Entering a current limit during voltage control:
During voltage control, a limit can be entered for the positive (p54141) and negative
(p54142) current.
In addition, the current limits to protect the power unit (r55115, see FP 6810) and the
dynamic voltage limits (r55195, r55190, see FP 6817) are active.
● Dynamic switchover, current control/voltage control (p54105)
To Next Page
Loading...
