Lenze 8400 User Manual

Lenze · 8400 HighLine · Reference manual · DMS 12.0 EN · 06/2017 · TD23 167
5 Motor control (MCTRL)
5.4 V/f characteristic control (VFCplus)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
 How to set the V
min
boost:
1. Operate motor in idle state at approx. 6 % of the rated motor speed.
2. Increase V
min
boost (C00016) until the following motor current is reached:
Motor in short-time operation up to 0.5 n
rated
• for self-ventilated motors: I
motor
≈ I
rated motor
• for forced ventilated motors: I
motor
≈ I
rated motor
Motor in continuous operation up to 0.5 n
rated
• for self-ventilated motors: I
motor
≈ 0.8 I
rated motor
• for forced ventilated motors: I
motor
≈ I
rated motor
5.4.3.3 Optimising the Imax controller
Using the Lenze setting of the current limitation controller, the drive is stable:
Most applications do not require optimisation.
The setting of the current limitation controller must be adapted if
• power control including great moments of inertia is performed.
• Recommendation: Increase of the reset time Ti (C00074/1
) of the I
max
controller.
• vibrations occur in the V/f control (VFCplus + encoder) mode during the intervention of the
current limitation controller.
• Recommendation: Increase of the reset time Ti (C00074/1) of the I
max
controller.
• overcurrent errors (e.g. OC3) occur due to load impulses or too high acceleration ramps.
• Recommendation: Reduction of the gain Vp (C00073/1
) and reset time Ti (C00074/1) of the
I
max
controller.
 Note!
V
min
boost is automatically calculated by the motor parameter identification using the
data specified on the motor nameplate so that a no-load current of approx. 0.8 I
rated
motor
results at the slip frequency of the machine.
V/f control (VFCplus + encoder)
If V/f control (VFCplus + encoder) is selected, we recommend a decidedly lower V
min
boost:
• In this case, select a V
min
boost which ensures that approx. 50 % of the rated motor
current flows at slip frequency when the motor is idling.
Parameters Info Lenze setting
Value Unit
C00073/1 VFC: Vp Imax controller 0.25
C00074/1
VFC: Ti Imax controller 65 ms

Lenze 8400 Specifications

General

Category	DC Drives
Series	8400
Protection class	IP20
Control Type	Vector control
Communication	CANopen, PROFIBUS, Ethernet
Protection Features	Overcurrent, overvoltage, undervoltage, overtemperature
Input Voltage	AC 230/400/480 V