Lenze Drive PLC Developer Studio 9300 Servo PLC (V8.x) - Manual (Page 70)

2.12 MCTRL_MotorControl (node number 131)
9300 Servo PLC
System blocks
2−56
L
9300 Servo PLC EN 5.0
2.12.12 Field weakening
Adjusting the field weakening range is not required if the motor type has been set under C0086. In
this case all necessary parameters are set automatically.
The motor is operated in the field weakening range if
·
the output voltage of the controller exceeds the rated motor voltage set under C0090.
·
the controller cannot increase the output voltage with increasing speed because of the mains
voltage / DC−bus voltage.
Under C0575 you can set a factor between 1 ... 8 to limit the maximum field weakening. "8" means
that the maximum field weakening is 8−fold.
Manual field weakening
The field can be weakened manually via MCTRL_nFldWeak_a.
·
For maximum excitation MCTRL_nFldWeak_a must be actuated with +100 % (= 16384).
·
If MCTRL_nFldWeak_a is not assigned (free), the field weakening is automatically +100 %.
Stop!
The available torque is reduced by the field weakening.
2.12.13 Switching frequency changeover
The following switching frequencies can be set for the inverter under C0018:
·
8 kHz for power−optimised operation
ð
maximum power output of the controller, but with
audible pulse operation.
·
16 kHz for noise−optimised operation
ð
inaudible pulse operation of the controller, but with
reduced power output (torque).
·
Automatic changeover between power−optimised and noise−optimised operation.
Code LCD Possible settings Info
Lenze Selection
C0018 fchop 1 Switching frequency
0 16/8 kHz automatic changeover Optimum noise reduction with
automatic changeover to 8 kHz
1 8 kHz sine Power−optimised operation
2 16 kHz sine Noise−optimised operation
Automatic switching frequency changeover
You can use the automatic switching frequency changeover if you want to operate the drive in the
noise−optimised range but the torque available in this mode is not high enough for acceleration
processes.
Condition M = f(I) Function
M < M
r16
(I
r16
) Controller operates with 16 kHz (noise−optimised)
M
r16
(I
r16
) < M < M
r8
(I
r8
) Controller switches to 8 kHz (power−optimised)
M > M
max8
(I
max8
) Controller operates with 8 kHz at its current limit