ABB ACS880-x04, Руководство по прошивке

Страница: 67 / 604

Program features 67
Quick configuration of the process PID controller
1. Activate the process PID controller (parameter 40.07 Set 1 PID operation mode ).
2. Select a feedback source (parameters 40.08 … 40.11 ).
3. Select a setpoint source (parameters 40.16 … 40.25 ).
4. Set the gain, integration time, derivation time, and the PID output levels ( 40.32
Set 1 gain , 40.33 Set 1 integration time , 40.34 Set 1 derivation time , 40.36 Set 1
output min and 40.37 Set 1 output max ).
5. The PID controller output is shown by parameter 40.01 Process PID output
actual . Select it as the source of, for example, 22.11 Speed ref1 source .
Sleep function for process PID control
The sleep function can be used in PID control applications that involve relatively long
periods of low demand (for example, a tank is at level), During such periods, the
sleep function saves energy by stopping the motor completely, instead of running the
motor slowly below the efficient operating range of the system. When the feedback
changes, the PID controller wakes the drive up.
Note: The sleep function is disabled when mechanical brake control (see page 70 ) is
active.
Example: The drive controls a pressure boost pump. The water consumption falls at
night. As a consequence, the process PID controller decreases the motor speed.
However, due to natural losses in the pipes and the low efficiency of the centrifugal
pump at low speeds, the motor would never stop rotating. The sleep function detects
the slow rotation and stops unnecessary pumping after the sleep delay has passed.
The drive shifts into sleep mode, still monitoring the pressure. The pumping resumes
when the pressure falls under the wake-up level (setpoint - wake-up deviation) and
the wake-up delay has passed.