Allen-Bradley PowerFlex User Manual

2-118 Process PI Loop
When the PI is enabled, the output of the PI Controller is added to the
ramped speed reference.
Exclusive Control
Process Control takes the output of PI regulator as the speed command. No
master speed reference exists and the PI Output directly controls the drive
output.
In the pumping application example below, the reference or setpoint is the
required pressure in the system. The input from the transducer is the PI
feedback and changes as the pressure changes. The drive output frequency
is then increased or decreased as needed to maintain system pressure
regardless of flow changes. With the drive turning the pump at the required
speed, the pressure is maintained in the system.
However, when additional valves in the system are opened and the pressure
in the system drops, the PI error will alter its output frequency to bring the
process back into control.
When the PI is disabled the commanded speed is the ramped speed
reference.
+
Spd Cmd
Process PI
Controller
Linear RAmp
& S-Curve
+
+
+
PI Enabled
Speed Control
Spd Ref
PI Ref
PI Fbk
Slip Adder
Open
Loop
Slip
Comp
Process
PI
PI Feedback
Motor
Pump
Desired Pressure
[PI Reference Sel]
Pressure
Transducer

Allen-Bradley PowerFlex Specifications

General

Category	DC Drives
Manufacturer	Allen-Bradley
Series	PowerFlex
Communication Options	EtherNet/IP, DeviceNet, ControlNet
Protection Features	Overcurrent, Overvoltage, Undervoltage, Overtemperature, Short Circuit
Enclosure Type	NEMA 1, NEMA 12, NEMA 4/4X
Operating Temperature	0°C to 40°C (32°F to 104°F)
Storage Temperature	-40°C to 70°C (-40°F to 158°F)
Humidity	5% to 95% (non-condensing)
Altitude	Up to 1000m (3280 ft) without derating