Close-Loop Control Parameters(Group F5) - Emerson EV2000 Series User Manual

5.6 Close-loop Control Parameters(Group F5)

There are two kinds of close loop control: analog
close-loop control (feedback value is analog value) and
pulse close-loop control (feedback value is pulse). Fig.
5-29 and 5-30 show the typical wiring of analog
close-loop control and pulse close-loop control
respectively.
EV2000
QF
R
3-phase
S
380V T
.
FWD
.
COM
.
G D
N
Fig. 5-29 Analog feedback control system with internal PI
QF
EV2000
R
3-phase
S
380V
T
· VRF
1-3K · VCI
GND
·
Fig. 5-30 Wiring of speed close-loop with PG
Analog feedback control system:
An analog feedback control system uses a water-level
sensor as the feedback sensor of the internal PI.
As shown in Fig. 5-29, pressure reference (voltage
signal) is input via terminal VCI, while the feedback
pressure value is input into terminal CCI in the form of
Reference
Reference
regulation
(F5.08 and F5.10)
U
Output
V
M
P
W
PE
.
P24
.
CCI
.
VRF
.
VCI
1-3K
.
GND
A/A
U
PG supply
V
M
PG
B/B
W
PE
PG GND
FWD ·
COM ·
X7 ·
·
P24
X8 ·
+
ε
-
Fig. 5-31 PI block diagram
EV2000 Series Universal Variable Speed Drive User Manual
0(4)~20mA current signal. The reference signal and
feedback signal are detected by the analog channel.
The start and stop of the drive can be controlled by
terminal FWD.
The above system can also use a TG (speed measuring
generator) in close speed-loop control
Close speed-loop using PG:
A close speed-loop control system uses external control
terminals X
As shown in Fig. 5-30, reference of speed close-loop
can be input by a potentiometer in the form of voltage
signal via terminal VCI, while the feedback value of the
Water-
level
close loop is input by PG in pulse mode via terminals X7
sensor
and X8. The start and stop of the drive can be controlled
by terminal FWD.
In Fig. 5-30:
A and B are PG's dual phase quadrature output;
P24 is connected to the power source of PG;
Speed reference is the voltage signal of 0~10V. The
voltage signal is in direct proportion to synchronous
speed n that corresponds to 0~Max frequency (F0.05),
0
and f is Max frequency (F0.05), and P is the number
max
of poles of motor(FH.00).
n =120 × f
0 max
Refer to F7.00~F7.07 for the functions of input terminals
X7 and X8.
Note:
1. The reference can also be input via panel or serial port;
2. Dual-phase input is good for improving the speed
measurement accuracy, while the wiring of single-phase
input circuit is simple;
3. Dual-phase pulse can only be input in quadrature mode;
4. If using the drive's terminal P24 to supply the power to
PG, then the Max load current of optical PG must be less
than 100mA.
Operating principles of internal PI of EV2000 is shown in
the Fig. 5-301.
Error limit
Regulation
(F5.16)
(F5.15)
Feedback
regulation
(F5.09 F5.11)
Chapter 5 Parameter Introductions
and X , and pulse generator(PG).
7 8
/P
ε
KP ×
(F5.12)
ε
Ki ×
∑
(F5.13)
55
+
Output
+
Feedback