Allen-Bradley PowerFlex 70 Enhanced Control - Current Limit

20 Bus Regulation
Figure 1 Bus Voltage Regulator, Current Limit and Frequency Ramp.
Bus Voltage Regulator
Current Limit
Magnitude
Calculator
Frequency
Ramp
(Integrator)
Frequency
Limits
Current Limit Level
U Phase Motor Current
W Phase Motor Current
Proportional Channel
Frequency
Reference
Acc/Dec Rate
Integral Channel
Bus Reg
I Limit,
No Bus Reg
Proportional Channel
I Limit,
No Bus Reg
Maximum Frequency, Minimum Speed, Maximum Speed, Overspeed Limit
Frequency Set Point
+
+
++
+
Output Frequency
Frequency Reference (to Ramp Control, Speed Ref, etc.)
Speed Control (Slip Comp, Process PI, etc)
Bus Voltage Regulation Point, V
reg
Bus Reg On
Bus Voltage (Vbus)
PI Gain Block
Speed
Control
Mode
0
No Limit
Limit
SW 1
SW 2
SW 3
SW 4
SW 5
Derivative
Gain Block
Jerk
Ramp
Jerk
Clamp
No Limit
PI Gain Block
Derivative Gain
Block
Integral Channel