KSB PumpDrive 2 - Closed-Loop Control Mode Via Control Panel

8 Commissioning/Shutdown
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PumpDrive 2
Determination of Controller Parameters Cancelled message. The single-pump system
or multiple pump system then continues to operate with the unchanged controller
parameters.
The process of automatically adapting the controller parameters can be modified if
required. This is done by three parameters:
▪ The extent of the speed changes during the test sequence is defined via the
Amount of Sudden Speed Change parameter (3-6-4-1-2). Typical values lie in the
range of 5 to 15% of the pump nominal speed.
▪ The Controller Type parameter (3-6-4-1-3) specifies whether the controller
parameters should be determined for a PI controller or a PID controller.
▪ The Process Response Time parameter (3-6-4-1-4) defines the time that lapses
after a speed change until the controlled variable exhibits almost no change at
all. After this time the controlled variable has reached approximately 95% of its
full-scale value. The default value defined is sufficient for the majority of
pressure or flow rate control tasks. Especially when very slow processes are
involved, such as those of temperature control, a sufficiently long test sequence
must be ensured via this value. The duration of determining the controller
parameters automatically directly relates to the time specified here.
Table52: Automatic determination of controller parameters
Parameter Description Possible settings Factory setting
3-6-4-1-1 Start Test Sequence
Starts the test sequence for automatically
determining the controller parameters
Run
3-6-4-1-2 Amount of Sudden Speed Change
Extent of speed changes during the test
sequence for automatic determination of
the controller parameters.
0…3-2-2-2 rpm 150rpm
3-6-4-1-3 Controller Type
Selection of the controller type: PI or PID
▪ PI
▪ PID
PI
3-6-4-1-4 Process Response Time
Time that lapses after a speed change until
the controlled variable exhibits almost no
change at all (after this time, the controlled
variable has reached approximately
95percent of its full-scale value)
0,1…10000s 3s
8.7.1.2.1 Closed-loop control mode via control panel
NOTE
The parameter values and value ranges/units entered are mutually dependent. This
is why the first step in parameterising the frequency inverter is always to specify the
applicable value range and units (refer to parameter 3-11). If the value range or
unit is subsequently changed, all dependent parameters must be checked for
correctness again.