Lenze EVF9383 - Manual (Page 247)

Configuration
Function blocks
Internal motor control with V/f characteristic control (MCTRL1)
8
8.2
8.2.6
l
8.2−31 EDSVF9383V EN 7.1−04/2012
ƒ The signal at the input MCTRL−N−SET is the setpoint speed in [%] and
always refers to the maximum speed (C0011).
ƒ In most basic configurations, MCTRL−N−SET is connected to the function
block NSET (speed setpoint conditioning).
– You can also connect MCTRL−N−SET to any other analog output signal
of a function block.
ƒ The speed setpoint at MCTRL−N−SET is always limited to ±100 % of the
maximum speed n
max
(C0011).
ƒ The motor control converts the speed setpoint into a frequency
setpoint, which is limited to a maximum output frequency, depending
on the switching frequency f
chop
Switching frequency f
chop
Maximum output frequency
2 kHz 150 Hz
4 kHz 300 Hz
The motor voltage characteristic is set via the input of the motor ratings.
Via the input MCTRL−BOOST the motor voltage can be raised. The input is
connected to C0016 (freely configurable) in all basic configurations.
ƒ To adapt the motor voltage boost to your application, you can also
connect the input with other function blocks.
With feedback operation, a PI controller will control the slip.
Activating the speed control
The speed control is activated when you select an incremental encoder in
C0025.
Parameter setting
Code Function
C0070 Gain V
p
C0071 Integral−action time T
n
C0074 Influence of the speed controller at operation with incremental encoder.
Reference is n
max
(C0011).
)
Note!
If the speed controller influence is adapted to the motor slip to
be expected, the motor cannot accelerate in an uncontrolled way
when the incremental encoder fails.
Adaptation of the speed controller
The gain of the speed controller can be changed online via the input
MCTRL−VP−N−ADAPT. The set gain in C0070 is the reference value for an input
signal of 100 %.
ƒ You can influence the gain (C0070) by adapting a function block (e.g.
CURVE) to MCTRL−VP−N−ADAPT.
ƒ The adaptation is switched off in the Lenze default setting.
Speed setpoint selection
Speed setpoint limitation
Setting of the V/f
characteristic
Speed control