2 0
Introduct
i
on and Techn
i
ca
l
Data
3.1
I
nt
r
odu
c
t
i
on
The PL/X D C motor contro
ll
er uses c
l
osed
l
oop contro
l
of armature current and feedback vo
l
tage to
g
i
ve prec
i
se contro
l
of motor torque and speed. The un
i
t a
l
so contro
l
s the motor exc
i
tat
i
on f
i
e
l
d. The c
l
osed
l
oop parameters are programmab
l
e by the user and a w ea
l
th of
i
nputs and outputs are prov
i
ded to a
ll
o w very
comp
l
ex mot
i
on contro
l
processes to be ach
i
eved. The ser
i
es
i
s compr
i
sed of 5 frame var
i
ants each w
i
th 2
and 4 quadrant mode
l
s.
S
e
l
ec
t
e
d 2 qu
a
d
r
a
nt mod
e
l
s
a
l
so off
e
r
a
un
i
qu
e
r
e
g
e
n
e
r
a
t
i
v
e
stopp
i
ng f
ac
ili
ty.
P
l
ea
s
e
a
l
so
r
e
f
e
r
to
Pa
r
t 3
PL
/X 275-980 fo
r
e
xt
r
a
d
e
t
a
il
s of f
r
a
m
e
4
a
nd 5 h
i
gh pow
e
r
d
ri
v
e
s.
Programm
i
ng the un
i
t
i
s des
i
gned to be s
i
mp
l
e. A
l
arge back
li
t a
l
phanumer
i
c d
i
sp
l
ay gu
i
des the user through a
fr
i
end
l
y menu structure to se
l
ect opt
i
ons and parameter changes. Bu
il
t
i
n app
li
cat
i
on soft w are b
l
ocks are
prov
i
ded to be connected up as des
i
red. Comprehens
i
ve fau
l
t mon
i
tor
i
ng and ser
i
a
l
commun
i
cat
i
ons a
ll
o w off
s
i
te programm
i
ng and remote d
i
agnost
i
cs. A
ll
mode
l
s are stock
i
tems. These un
i
ts are very compact. The
sav
i
ngs made poss
i
b
l
e
i
n pane
l
space and enc
l
osure costs may be s
i
gn
i
f
i
cant.
3.2 How do th
e
y wo
r
k
?
Th
i
s sho w s the bas
i
c arrangement of the dr
i
ve contro
l
l
oops. The 3-phase thyr
i
stor br
i
dge
i
s a phase-
contro
ll
ed rect
i
f
i
er, w h
i
ch de
li
vers po w er to the motor armature. The armature current (and hence the motor
torque)
i
s sensed to prov
i
de feedback to the
i
nner current
l
oop. A fter be
i
ng sca
l
ed th
i
s
i
s compared to the
current demand. The current error amp
li
f
i
er
i
s ab
l
e to detect any d
i
fference, and then act
i
n such a w ay that
the current feedback rema
i
ns
i
dent
i
ca
l
to the current demand dur
i
ng norma
l
operat
i
on. Th
i
s
i
nner
l
oop
mon
i
tors the armature current and de
li
vers more current or
l
ess current as requ
i
red.
The outer speed
l
oop w orks
i
n the same w ay as the
i
nner current
l
oop but uses d
i
fferent parameters. In the
above examp
l
e, the demand
i
s prov
i
ded by the user
i
n the form of a speed reference, and the speed feedback
i
s der
i
ved from a shaft-mounted tachometer. A ny d
i
fference
i
s detected and trans
l
ated
i
nto a ne w current
demand
l
eve
l
. Th
i
s
l
eve
l
prov
i
des the r
i
ght amount of current (and hence torque) to reduce the speed error to
zero. Th
i
s ne w demand
l
eve
l
i
s presented to the
i
nner current
l
oop, w h
i
ch obeys as rap
i
d
l
y as poss
i
b
l
e.
The w ho
l
e process
i
s performed on a cont
i
nuous bas
i
s g
i
v
i
ng superb speed accuracy and dynam
i
c
performance. In typ
i
ca
l
systems, there are numerous house keep
i
ng tasks and
i
nterface requ
i
rements. For
these, the PL/X ser
i
es has a w ea
l
th of standard features to benef
i
t the user.
A range of standard app
li
cat
i
on b
l
ocks
i
s
i
nc
l
uded, w
i
th a user-fr
i
end
l
y conf
i
gurat
i
on fac
ili
ty that d
i
sp
l
ays a
descr
i
pt
i
on of the se
l
ected connect
i
on po
i
nts. The programm
i
ng menu
i
s des
i
gned for rap
i
d trave
l
to the
des
i
red parameter us
i
ng 4 keys and a
l
arge back
li
t a
l
phanumer
i
c d
i
sp
l
ay. A
l
arge number of mon
i
tor
i
ng
fac
ili
t
i
es
i
s ava
il
ab
l
e to enab
l
e d
i
sp
l
ay of a
ll
po
i
nts
i
n the b
l
ock d
i
agram.
The un
i
t
i
s supp
li
ed w
i
th
PL
P
I
L
OT
, a superb PC w
i
ndo w s based conf
i
gurat
i
on and mon
i
tor
i
ng too
l
.
(Note. A
l
so ava
il
ab
l
e
i
s the PLA , w
i
th app
li
cat
i
ons b
l
ocks, I/O modu
l
es and comms fac
ili
t
i
es on
l
y)
Inner current
l
oop
Speed
reference
from user
Current
error
amp
li
f
i
er
Speed
error
amp
li
f
i
er
Current
feedback
sca
li
ng
Speed
feedback
sca
li
ng
F
i
r
i
ng c
i
rcu
i
t and
3-phase br
i
dge.
A C
i
n, D C out.
M
Tacho
The s
i
gna
l
here
represents armature
current demand.
Outer
speed
l
oop
Содержание PLX
Страница 2: ...2 Contents ...
Страница 202: ......