Lenze E84DSxxx - Manual (Page 121)

Lenze · 8400 protec StateLine · Reference manual · DMS 4.2 EN · 03/2013 · TD05
121
5 Motor control (MCTRL)
5.4 V/f characteristic control (VFCplus)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
5.4.3.2 Adapting the Vmin boost
The V
min
boost ( C00016 ) of the motor voltage serves to select a load independent magnetising
current which is required for asynchronous motors. The torque behaviour of the motor can be
optimised by adapting the setting in C00016 .
The general linear and quadratic V/f characteristics are shown in the illustrations below. The
illustrations show the impacts of the parameters used to adapt the characteristic shape.
[5-5] Representation of the linear V/f characteristic (on the left) and quadratic V/f characteristic (on the right)

Note!
87-Hz operation
4-pole asynchronous motors which are designed for a rated frequency of f = 50 Hz in star
connection can be operated in delta connection when being constantly excited up to f =
87 Hz.
• Advantages:
• Higher speed-setting range
• 73% higher power output in case of standard motors
• Motor current and motor power increase by the factor .
• The field weakening range starts above 87 Hz.
• Generally, this process can also be used with motors which have different numbers of
pole pairs. In case of 2-pole asynchronous motors, the mechanical limit speed must be
maintained.
3

Note!
The V
min
boost has an effect on output frequencies below the V/f base frequency
( C00015 ).
C00015
C00016
C00015
2
C00016
2
V [V]
out
f [Hz]
V
(100 %)
rmot
1/N/PE AC 264 V
3/PE AC 264 V
3/PE AC 550 V
1/N/PE AC 180 V
3/PE AC 100 V
3/PE AC 320 V
C00015
C00016
V [V]
out
f [Hz]
V
(100 %)
rmot
1/N/PE AC 264 V
3/PE AC 264 V
3/PE AC 550 V
1/N/PE AC 180 V
3/PE AC 100 V
3/PE AC 320 V