Normally, when using a drive, we set the running speed manually from an external source and the motor runs at the speed that we have set.
With a PID setup, You basically give the drive permission to run the motor at any speed (Within defined limits) to achieve a desired application response.
This is known as a 'Closed Loop' Control application.
An Open loop control system has NO feedback. We instruct the motor to run at a speed, but the drive does not 'know' if the motor is actually running at all.
A Closed loop system uses some kind of feedback from the system being controlled, which allows the drive to respond to the changing variables within the application. For example, as pressure drops, the drive can automatically change the motor speed to account for this and try to maintain the target that we have set.
For example, we can connect a pressure sensor to the output of a pump and then make the drive run the pump motor at whatever speed is needed to maintain a certain pressure output from the pump.
When the pump is started, the speed will increase rapidly to get to the target set-point.
Once the pressure set point is reached, the motor will slow down and if we are maintaining the required pressure, we can even turn off the motor and let the drive go into a sleep mode until the pressure drops below a certain value.
When the pressure drops, the drive will wake up and start running the motor again.
How to set the ATV12 drive for PID control using internal reference and analogue feed back for constant pressure.
If you need details of the PID commands in more detail, or prefer a written format description, please access the ATV12 User manual.
You can go to your local country Schneider Website and type the search string 'ATV12 User' in to the search bar at the top of the page to find the latest version.
If you use Ctrl - F within the document, You can search for the term PID to find the complete instruction set in the application functions section of the manual From PAGE 72 Onwards.
In the user manual document BBV28581 (Dated 06/2023), there is an example of pumping pressure control with PID given from PAGE 81 to PAGE 88
https://www.se.com/uk/en/download/document/BBV28581/
With a PID setup, You basically give the drive permission to run the motor at any speed (Within defined limits) to achieve a desired application response.
This is known as a 'Closed Loop' Control application.
An Open loop control system has NO feedback. We instruct the motor to run at a speed, but the drive does not 'know' if the motor is actually running at all.
A Closed loop system uses some kind of feedback from the system being controlled, which allows the drive to respond to the changing variables within the application. For example, as pressure drops, the drive can automatically change the motor speed to account for this and try to maintain the target that we have set.
For example, we can connect a pressure sensor to the output of a pump and then make the drive run the pump motor at whatever speed is needed to maintain a certain pressure output from the pump.
When the pump is started, the speed will increase rapidly to get to the target set-point.
Once the pressure set point is reached, the motor will slow down and if we are maintaining the required pressure, we can even turn off the motor and let the drive go into a sleep mode until the pressure drops below a certain value.
When the pressure drops, the drive will wake up and start running the motor again.
How to set the ATV12 drive for PID control using internal reference and analogue feed back for constant pressure.
If you need details of the PID commands in more detail, or prefer a written format description, please access the ATV12 User manual.
You can go to your local country Schneider Website and type the search string 'ATV12 User' in to the search bar at the top of the page to find the latest version.
If you use Ctrl - F within the document, You can search for the term PID to find the complete instruction set in the application functions section of the manual From PAGE 72 Onwards.
In the user manual document BBV28581 (Dated 06/2023), there is an example of pumping pressure control with PID given from PAGE 81 to PAGE 88
https://www.se.com/uk/en/download/document/BBV28581/
Released for:Schneider Electric Ireland
