With increasing electricity prices and the continued pressures of an increasingly competitive marketplace it’s no wonder businesses are looking for other ways to improve their bottom line.
Identifying opportunities for process optimisation, efficiency gains and energy savings are key to stay competitive in today’s market and increase a business’s profitability.
PID control is a control principle that can help to achieve remarkable energy savings when applied to the correct application. PID control is not new, in fact it was originally developed in the 1890s! Since this time the benefits of using PID have seen it adopted in various industrial control systems – although it is still somewhat underutilised in industry.
PID control or Proportional-Integral-Derivative control is a control principle which works in a closed loop feedback system. Essentially the PID controller calculates the difference between the measured actual process value and the desired setpoint value – this is called the error. The controller then corrects for this error by adjusting the process outputs.
An example of a PID control in action can be seen here with a Variable Speed Drive (with inbuilt PID controller), a pump motor, and a pressure transmitter. The VSD is given a desired setpoint pressure to run the system at. Closed loop feedback of the actual pressure is given to the VSD from the pressure transmitter. As the external variables change (Ie. demand for water from users down the line.) The inbuilt PID controller of the VSD will react and increase or decrease the pump speed to maintain the required pressure setpoint.
When you start to think differently about your process you will see that you can utilise VSD’s and abandon inefficient throttling methods such as analog valves, and air dampers.
Example applications where PID control can used to achieve improved optimisation and energy savings are;
- Pumps & Fans
- Cooling fans
- Water pressure
- Water flow
- Water level control
- Temperature Control
By using a correctly configured PID control it’s possible to achieve sizable improvements in Process optimisation, plant efficiency and energy savings.