Remote Laboratory Experiment

PID-control of the membrane compressor’s pressure

Motivation

This experiment is dedicated to the tuning of a proportional-integral-derivative controller (PID controller) for the variable frequency driven membrane compressor.

You will learn about compressors, structural diagrams, systems’ dynamics, controllers, and transients in electric drive systems.

The subject area of this experiment primarily targets the field of control engineering. The prerequisite of doing this work is knowledge of electric motors, variable frequency drives. At each page there is a brief description and links to the resources in those fields.

This remote laboratory experiment is designed for the 3d and 4^th year students of the specialties relating to electrical engineering, mechatronics, automation and electric drives.

The test stand with remote access

The test stand, i.e. the control plant comprises the frequency converter, induction motor and the membrane compressor. The purpose of the set is to control the pressure in the receiving chamber.

The RLE (remote lab experiment) setup is equipped with digital pressure sensor. This signal, together with internal signals from the frequency converter is relayed into the control panel, it is the “Dashboard” tab on this page.

In the Dashboard tab you can find the control buttons for operating the compressor’s drive, windows for setting the controller’s gains and the oscillogram of the pressure signal during the transients There is also the live video stream of the test stand which you can directly access via your browser.

The idea and objectives of the experiment

From this experiment, you will learn to tune the PID controller.

The transient process of the pressure may be slower or faster, with or without oscillations – depending on the parameters of electric drive control systems.

Thus, you will see how the proportional, integral and derivative components of the controller affect the dynamic behavior of the drive set.

Try altering the parameters of the controller one-by-one and make conclusions on how the P-, I- and D- components change the curve of the transients.

Step-by-step instructions. Videos

The layout of this web-page is done exactly the way you should perform your practical assignment.

Just follow the tabs from left-to-right and read or perform action from top-to-down and you will have the experiment completed. Follow the instructions step by step

The ‘Membrane compressor’ tab

First, study what you are dealing with - the subject area. In the next tab you can find info about the compressor, its physics and mechanics. You will need the equations describing the compressor in order to understand the composition of the dynamic model. There you can find the links to the more detailed info about pumps and compressors.

The ‘Theoretical background’ tab

This tab is about control theory. You will learn about the transients and different approaches for controller build-up.

Experiment. The Dashboard

At this tab you will actually do the experiment. There you will find the control buttons, windows for setting the parameters, live oscilloscope and live video.

Testing and reporting

Don’t worry, it’s peace of cake!

Answer a simple quizz and submit your report.