Emerson EV1000-2S0004G User Manual page 35

EV1000
QF
R
380V S
T
.
FWD
.
COM
.
GND
Figure 5-28 Build-in PI Analog Feedback Control
QF
EV1000
R
380V
S
T
·
VRF
1-3K
·
VCI
GND
·
Figure 5-29 PG Speed Close Loop Control System
Analog feedback control system:
An analog feedback control system can be formed by a
pressure transducer as the feedback sensor of the internal
PI.
As shown in, pressure reference (voltage signal) is input via
terminal VCI, while the feedback pressure value is input to
terminal CCI in the form of 0~20mA 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.
Reference
Reference
regulation
(F5.08 and F5.10)
Where:
KP proportional gain; Ki: integral gain. In Figure 5-30, refer
to F5.01~F5.15 for the definitions of close-loop reference,
feedback, error limit and proportional and Integral
parameters.
There are two features of internal PI:
The relationship between reference and feedback can be
defined by F5.08~F5.11.
For example: In Figure 5-2828, if the reference is 0~10V
analog signal, the expected controlled value is 0~1MP, and
the pressure signal is 4~20mA, then the relationship
between reference and feedback is shown in Figure 5-31.
U
Output
V
M
P
W
Pressure
PE
transducer
.
P24
.
CCI
.
VRF
.
VCI
1-3K
.
GND
A/A
U
PG power supply
M
V
PG
B/B
W
PE
PG ground
FWD
·
COM
·
X4
·
P24
·
X5
·
+
ε
-
Figure 5-30 PI Working Mechanism
EV1000 Series General Purpose Variable Speed Drive User Manual
The above system can also use a TG (speed measuring
generator) as speed close speed-loop control
PG speed close-loop control:
A speed close-loop control system can be formed by
external control terminals X
(PG) .
As shown in Figure 5-29, close speed-loop input can come
from a potentiometer in the form of voltage signal via
terminal VCI, while the feedback value of the close loop is
input by PG in pulse mode via terminal X4 and X5. The start
and stop of the drive can be controlled by terminal FWD.
In Figure 5-29,
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 corresponds to synchronous speed n
corresponds to 0~Max frequency (F0.05) . P is the number
of poles of motor (FH.00) .
n =120 × f
0 max
Refer to function No. 47~48 of F7.00~F7.04 for the functions
of input terminals X4, X5.
Note
1. The reference can also be input via keypad or serial port;
2. Dual-phase input can improve the speed measurement accuracy,
while single phase input wiring is simple;
3. Dual-phase pulse can only be input in quadrature mode;
4. If PG is supplied from terminal P24, then the max load current
of optical PG must be less than 100mA.
The mechanism of the build-in PI is shown in the figure
below.
Error limit
Regulation
(F5.16)
(F5.15)
Feedback
regulation
(F5.09 F5.11)
20mA
4mA
Figure 5-31 Reference (Input) and Feedback
Chapter 5 Parameters
and X , and pulse generator
4 5
/P
ε
KP ×
(F5.12)
ε
∑
Ki ×
(F5.13)
Feedback
0
10V
33
which, in turn,
0
+
Output
+
Feedback
Reference