System
The experiments are set up with experimental panels in the profile frame. The Profi-CASSY is used to control this technical controlled system and to record and analyse the measured values.
Learning objectives
- Measurement of frequency responses
- Discussion of control systems in the frequency range
Function
The frequency response of a system is usually represented graphically, whereby a distinction must be made between the representation in the form of the Bode diagram and the Nyquist locus curve. This equipment is used to measure the frequency response of real transmission elements. A PI controller is designed for a PT3 controlled system using the compensation method. In the Bode diagram, the stability of the closed control loop is determined from the phase reserve for the open loop.
Method
The equipment includes student experiments in the laboratory with non-hazardous low voltage. Experimental procedures are carried out using a manual in printed or electronic form.
Target group
An internship aimed at further education programmes at technical colleges and technical universities.
Previous knowledge
- Knowledge of classical control engineering.
Additions
The following equipment is recommended for in-depth study:
- E6.3.4.1 Control of electronic routes
- E6.3.4.2 Digital control
- E6.3.4.3 Fuzzy control
Topics
- Graphical representation of the frequency response
- Frequency responses of basic control elements (P, PT1, PT2, PTt, I)
- Frequency response of the oscillating PT2 element
- Frequency response of the PTt dead time element
- Frequency response of the I-element
- Frequency response of series circuits
- Frequency response of the PID controller
- Stability of control loops
- Controller design in the frequency range
