6
6
KEB COMBIVERT F5-M / S
8
Name: Basis
12.05.04
Chapter
Section
Page
Date
©
KEB Antriebstechnik, 2002
All Rights reserved
Functional Desription
Motor Data and Controller
In the base speed range the maximum torque is mainly limited by the hardware
current limits of the inverter. For a stable operation the control requires voltage
reserves in order to balance currents at any time, therefore the torque that can be
reached in the higher speed range is limited by the output voltage. The limit
characteristic is adjusted correctly when a voltage reserve of approx. 5Ö10 % of
the rated voltage is available at every operating point.
In this parameter the speed is adjusted at which the field weakening operation
starts.
With the parameters dr.19, dr.20 the flux characteristic can be adapted to the
motor.
In this parameter the field weakening characteristic is adjusted. The value of 1
means that the flux is lowered after an 1/n function.
6.6.5 Flux Lowering
Calculation
DASM field weakening speed
(dr.18)
Field weakening curve (dr.20)
Flux adaption factor (dr.19)
Fig. 6.5.5 Flux lowering
1
2
dr.20 < 1
dr.20 = 1
dr.20 > 1
Field weakening curve (dr.20)
Flux adaption factor
(dr.21)
set value ( ru .1 ) + slip
field weakening speed (dr.18)
The motor torque which has been calculated from the motor parameters is displayed
in dr.14. Parameter dr.15 indicates the maximum torque which is achieved in the
base speed range. It depends on the hardware current limitation - 5% and cannot
be altered.
Speed
Fig. 6.5.4.b
Torque limitation
DASM rated torque (dr.14)
max. torque (dr.15)
DASM max. torque at field weak
speed (dr.16)
DASM speed f. max. torque†(dr.17)
DASM field weak speed (dr.18)
Torque
Max. torque (dr.15)
DASM max. torque at field
weakening speed (dr.16)
Torque limitation (CS.20...22)
DASM field weakening
speed (dr.18)
DASM speed f. max.
torque (dr.17)
Available torque at the drive
Limiting line of motor torque