Dual Current Command Mode - Allen-Bradley Ultra1500 2092-DA1 User Manual

Dual Current Command Mode

Figure 5.26 shows the block diagram for the dual current mode of the
Ultra1500:
Figure 5.26
Dual Current Mode Block Diagram
Ana log Velocity
Co mman d (V olts)
1
Analo g V elocity
Command
Offset (V olts)
Analog Current
Command (Vo lts)
2
Analog Current
Comma nd
O ffset (Volts)
Block/Switch Definitions:
1 Mode Configuration : Analog : Velocity Command Offset
2 Mode Configuration : Analog : Current Command Offset
3 Mode Configuration : Analog : Current Scale
4 Main Drive Window : Command Polarity
5 Main Drive Window : Current Limits; Main Drive Window : Stopping Functions : Maximum Stopping Current
Block/Switch definitions shown in Figure 5.26 refer to the Ultraware parameter names where applicable.
In this operating mode, an external controller performs all commutation
functions, and the Ultra1500 drive functions as a simple three-phase current
regulator.
•
If the command polarity is set to Normal, the U phase current command
comes from the analog velocity input and the W phase current command
comes from the analog current input.
•
If the command polarity is set to Inverted, the U phase current command
comes from the analog current input and the W phase current command
comes from the analog velocity input.
The current command limit is set to the minimum of the following:
•
Positive / Negative Internal Current Limit,
•
Positive / Negative External Current Limit,
•
Stopping Current (if active), and
•
Drive Peak / Motor Peak Current Rating.
3 U Phase
+
4
K
Co mman d
c
+
3
+
4
K
Command
c
+
Ultra1500 Application Examples
UV W P hase Curren t
Command to
Current
5
Current Regu lato r
Ph ase Curren t
Cmd Amplitu de
L imit
W P hase
Curren t
Publication 2092-UM001D-EN-P — July 2005
5-45