Schematic

Closed Loop Speed Mode with Constant Slip Control
Advanced Digital Motor Controller User Manual 117
Watt
V
Amps
RPM
Nm
50Hz
Encoder 64 Pulses
3500
48Bat
100
1450
23
V fase 3 x 27
For this motor, the VPH can be determined by dividing the 27 Volts per phase by the 50Hz
frequency. In this case 0.54 Volts per Hertz.
Note that this value is for the optimal torque as rated on the label. If the load is a lot light-
er, the VpH will be too high and result in excessive current consumption. If the load is a
lot heavier, the VpH will be too low and the motor will not be able to drive it. The VpH will
therefore need to be different than this computed based on actual load conditions. Always
first monitor the motor consumption at no load. Adjust the VpH to a lower value if the no
load current appears too high.
Maintaining Slip within Safe Range
Open Loop, or Scalar, mode does not require encoders for its operation. If the load is
known to always be within the motor’s max torque, the motor can be trusted to always
be able to drive it. In this case, an encoder does not need to be connected. If an encoder
is connected - to measure and report speed, for example - then it must be configured as
“No Action” in the PC Utility.
For added safety, however, an encoder can be installed and enabled to measure the ro-
tor’s speed, and therefore the slip, in real-time. When the encoder is enabled and config-
ured as “Feedback”, the controller will lower the voltage and frequency if the slip exceeds
twice the value stored in the Optimal Slip configuration.
Prior to enabling the encoder as Feedback, verify that the encoder count direction has the
same polarity as the motor command.
Closed Loop Speed Mode with Constant Slip Control
In this mode, the controller will automatically adjust the voltage and frequency in order to
reach and maintain a desired speed, even as the load is changing, while operating within
the optimal slip range.
To configure this mode, first set the controller in open loop mode as described in the pre-
vious section. Verify that the encoder is working and is counting with the correct polarity.
Once the encoder is verified to work and the motor spins in open loop, follow these
steps. Using the Roborun PC utility:
• Select Close Loop Constant Slip Mode