Functional Software description
34
DCS 500 Software Description
Speed Actual
Comparators
There are four comparators available for speed actual monitoring.
When the speed actual is below the value of parameter
MIN
SPEED L (2201)
, the output
MIN SPEED (12201)
is set to logical
state 1. This is used as zero speed indication.
Signal output
SPEED GT L1 (12202)
is active when actual speed is
above speed level
SPEED L1 (2202)
. Parameter
SPEED L2 (2203)
and output
SPEED GT L2 (12203)
have the same function.
Overspeed limit
The drive can be protected against overspeed e.g. in cases where a
drive section is controlled with the torque reference and the load is
decreasing rapidly. The overspeed limit is set with parameter
OVERSPEEDLIMIT (2204)
, scale: speed units, range: (0....30 000)
20000 = 100%. Motor overspeed fault (code 37) will be activated, if
overspeed limit is exceeded. Default value is 23000.
Speed Measu-
rement Fault
The speed measurement supervision is based on the relationship of
the measured speed and measured/calculated EMF. Parameter
MON.MEAS LEV (2209)
is the minimum absolute value that the
measured speed must have when
EMF ACT (10506)
is above the
limit
MON.EMF (2210)
. Otherwise the speed measurement fault is
activated (fault code 14).
Q
R
S
SR
MUL
X
MUL
X
MUL
X
AND2
&
AND2
&
I1
I2
I1<I2
I1=I2
I1>I2
COMP-I
I1
I2
I1<I2
I1=I2
I1>I2
COMP-I
I1
I2
I1<I2
I1=I2
I1>I2
COMP-I
I1
I2
I1<I2
I1=I2
I1>I2
COMP-I
OR2
>1
-
ACT
SW-C1
MON EMF V (2210)
MON.MEAS LEV (2209)
SPEED MEAS FAULT
EMF ACT (10506)
FIELD1 REV ACK
-1
-1
+1
-1
RESET
SPEED ACT (12102)
Figure
19
Speed measurement fault logic diagram
Stall Protection
The stall protection stops the converter when the motor is in appar-
ent danger of overheating. The rotor is either mechanically stalled
or the load is otherwise continuously too high. The selection of the
stall protection is made by parameter
STALL SEL (2205)
.
0 =
stall ptotection disabled
1 =
stall protection enabled
The stall protection is activated if the following conditions are full-
filled:
Summary of Contents for DCS 500B
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