Industrial Engineer · phase 11 of 16
Internal PID
Drive-based proportional-integral-derivative controller that adjusts motor speed to regulate process feedback.
The Explain card
- Plain English
- The internal PID is a control loop built into the drive that adjusts motor speed to hold a process measurement at a setpoint. The transmitter wires to the drive and the drive does the whole job.
- Example
- A booster pump holds 60 psi in a building. The pressure transmitter feeds the drive's analog input, the setpoint is 60, and the drive speeds up or slows down to keep it there with no PLC involved.
- Why it matters
- For a single pump or fan holding one variable it removes a controller, its program and a network. The loop lives in the drive's parameters, so its tuning and its setpoint are invisible to whoever is looking at the PLC.
- Hook
- A whole control loop, hiding in the drive.
Where it sits in the deck
Phase 11: VFD Control Modes and Tuning
How a drive decides what to send the motor, from plain volts per hertz up to closed loop vector control, and how each mode is tuned.
