Firmware
≤
11.00 - DMS 8.0 EN - 10/2011
L
129
8400 StateLine C | Reference manual
Motor control (MCTRL)
V/f characteristic control (VFCplus)
5.4.2.1
Defining the V/f characteristic shape
In principle, four different characteristic shapes can be stipulated:
1.
Linear V/f characteristic
:
For drives for a constant, speed-independent load torque.
2.
Quadratic V/f characteristic
:
For drives with a load torque curve which is quadratic or in relation to speed. Quadratic
V/f characteristics are preferred in the case of centrifugal pumps and fan drives.
3.
Freely definable V/f characteristic
(from version 04.00.00)
:
For drives that require adaptation of the magnetising current by means of the output
speed. The freely definable V/f characteristic can be used e.g. for operation in
conjunction with special machines such as reluctance motors in order to suppress
oscillations at the machine or to optimise energy consumption.
[5-3]
Principle of a linear V/f characteristic (on the left) and a quadratic V/f characteristic (on the right)
4.
Linear V/f characteristic with voltage reduction
(from version 10.00.00)
:
For drives which often work in partial load operation, the energy-saving V/f
characteristic control (VFCplusEco) offers the opportunity to reduce the voltage at low
load in order to save energy. At higher loads, the voltage reduction is cancelled and a
linear characteristic is caused.
The V/f characteristic shape is defined by selecting the corresponding motor control mode
in
C00006
:
Tip!
• You can find detailed information on freely definable V/f characteristics in the
subchapter entitled "
Defining a user-defined V/f characteristic
".
(
140)
• You can find detailed information on the linear V/f characteristic with voltage
reduction in the chapter entitled "
V/f characteristic control - energy-saving
(VFCplusEco)
".
(
144)
0
1
0
100 %
N
n
n
U
min
U
out
0
1
0
100 %
N
n
n
U
min
U
out
V/f characteristic shape
Motor control to be selected (C00006)
Linear V/f characteristic
6: VFCplus: V/f linear
Square-law V/f characteristic
8: VFCplus: V/f quadr
User-definable V/f characteristic
10: VFCplus: V/f definable
Linear V/f characteristic with voltage reduction
11: VFCplusEco: V/f energy-saving
Phone: 800.894.0412 - Fax: 888.723.4773 - Web: www.clrwtr.com - Email: info@clrwtr.com
