Imax Controller; Flying Restart Controller - Lenze i950 Commissioning Manual

Configuring the motor control
Options for optimising the control loops
Motor control settings
13.6.5.7

Imax controller

Defining the behaviour at the current limit (Imax controller)
The maximum output current or the current limit is defined by the
parameter. In case of the V/f characteristic control, an Imax controller is implemented for
complying with this limit. If the motor current exceeds the set maximum current, the Imax
controller is activated.
The Imax controller changes the rotating field frequency so that the motor current does
•
not exceed the current limit. In motor mode, the frequency is reduced and in generator
mode it is increased.
The gain and reset time of the Imax controller can be parameterised.
•
Optimising the Imax controller
The automatic calculation serves to determine starting parameters of the Imax controller
which are sufficient for many applications. Thus, an optimisation is not required for most of
the applications.
The automatic calculation is made via the parameter 0x2822:019 = 1.
The parameters of the Imax controller must be adapted if
a power control is implemented with great moments of inertia.
•
Recommendation:
Step 1: increase reset time in
Step 2: reduce gain in
40x2B08:001
vibrations occur with V/f characteristic control during the operation of the Imax controller.
•
Recommendation:
Step 1: increase reset time in
Step 2: reduce gain in
40x2B08:001
overcurrent errors occur due to load impulses or too high acceleration/deceleration
•
ramps.
Recommendation:
Step 1: reduce reset time in
Step 2: increase gain in
40x2B08:002
Parameter
Address Name / setting range / [default setting]
0x2B08:001 V/f Imax controller: Gain
0.000 ... [0.001] ... 1000.000 Hz/A
0x2B08:002 V/f Imax controller: Reset time
1.0 ... [100.0] ... 2000.0 ms
13.6.5.8

Flying restart controller

Parameter
Address Name / setting range / [default setting]
0x2BA1 Flying restart circuit
0 ... [15] ... 100 %
248
40x2B08:002
40x2B08:002
40x2B08:001
0x6073 "max. current"
Info
Gain factor Vp of the Imax controller.
Reset time Ti of the Imax controller.
Info