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6-20
Programming Your Application
590+ Series DC Digital Converter
CURRENT LOOP
Parameter
Tag
Range
INT. GAIN
17
0.00 to 200.00
Integral gain control for armature current PI loop, set during the autotune function.
FEED FORWARD
136
0.10 to 50.00
Set by Autotune but not used by the default I-Loop mode.
DISCONTINUOUS
137
0.00 to 200.00 %
Sets the boundary between the discontinuous and continuous regions of the current signal.
This is set during the autotune function and affects the performance of the adaptive
algorithm.
ADDITIONAL DEM
30
-200.00 to 200.00 %
Additional current demand input.
BIPOLAR CLAMPS
90
DISABLED / ENABLED
Selects between bipolar (asymmetric) or unipolar (symmetric) current clamps for the 4
quadrants of operation. Default setting of DISABLED means UNIPOLAR clamps selected.
DISABLED - unipolar (symmetric)
ENABLED - bipolar (asymmetric)
With BIPOLAR CLAMPS disabled, the clamps are symmetrical and are set by POS. I
CLAMP. With BIPOLAR CLAMPS enabled, the clamps are assymmetrical, bipolar. In
bipolar mode, POS. I CLAMP sets the maximum positive current and NEG. I CLAMP sets
the maximum negative current. POS. I CLAMP must always be set algebraically higher than
NEG. I CLAMP. As a result, NEG. I CLAMP can be set to a positive value. CUR.
LIMIT/SCALER scales both POS. I CLAMP and NEG. I CLAMP.
REGEN MODE
201
DISABLED / ENABLED
When disabled, sets the drive for non-regenerative (2-quadrant) operation.
Note: We recommend that this parameter is not changed whilst the machine is running.
DISABLED - non-regenerative (2-quadrant)
ENABLED - regenerative (4-quadrant)
When REGEN MODE is DISABLED, negative current demands are clamped to zero.
Current feedback is subtracted from the current demand and the result is controlled by the PI
loop. The result provides SCR phase angle control.
POS. I CLAMP
301
-100.00 to 100.00 %
Positive current clamp when BIPOLAR CLAMPS is ENABLED.
NEG. I CLAMP
48
-100.00 to 100.00 %
Negative current clamp when BIPOLAR CLAMPS is ENABLED.
Note on bipolar current clamps:
t
hese clamps in bipolar mode can cross-over onto the same
quadrant as long as the POS. I CLAMP is always greater (algebraically) than the NEG. I
CLAMP.
I DMD. ISOLATE
119
DISABLED / ENABLED
Speed loop bypass; the current demand is taken from ANIN 2 (A3).
With I DMD. ISOLATE disabled, the current loop uses the current demand from the speed
loop. With I DMD. ISOLATE enabled, ANALOG I/P 2, terminal A3, supplies the current
demand. With default scaling, 10V dc on terminal A3 is 100% current demand. An additional
current input, ADDITIONAL DEM, can be added to the current demand. The simplified
diagram below shows how the I DMD ISOLATE parameter selects the controlling loop.
SPEED LOOP PI
CURRENT LOOP PI
Speed Demand
Speed Feedback
Analog I/P2 (A3)
Digital I/P3 (C8)
I DMD ISOLATE
Current Demand
Current Feedback
Motor
shown ENABLED
+
-
+
-