Induction machine: physical principles, working principle, mathematical model. Torque-speed characteristics of an induction machine. V/f control, different V/f characteristics. Speed control of induction motor by using frequency converter. Frequency converter structure, operating principle, energy flow direction. Open and closed loop control. Laboratory setup for control of induction machines. Digital and analog inputs, digital, relay and analog outputs, encoder interface. Specific functions of the industrial frequency converter. Individual work with the industrial frequency converter - commissioning, gain tuning of speed controller, connection to programmable logic controller via industrial communication protocol.

Fundamentals of electrical machines control. Experience in the application of frequency converter for AC induction machine and BLDC machine control. Experience in application of industrial software tools for parameter tuning of frequency converters, commissioning of frequency converter for AC induction motor and BLDC motor control, recording and analysis of measured values.

1. explain the operating principle of induction motor
2. explain the basic principle of AC/DC/AC converter
3. distinguish V/f characteristics
4. select appropriate V/f control structure with respect to load requirements
5. apply industrial software tools to adjust the parameters of frequency converter
6. use industrial frequency converter for speed control of induction motor
7. solve specific tasks regarding control of induction drive by adapting industrial frequency converter to address particular application

Lectures

One hour lecture is held each week.

Exercises

Exercises are held in the first cycle 4 times for 1 hour.

Laboratory Work

Laboratory exercises consist of six exercises, each lasting for 5 hours. Laboratory exercises are conducted on a laboratory model based on industrial frequency converter Siemens Sinamics G120. Two laboratory exercises are held in the first cycle and four in the second cycle.

Experiments

The lectures will take place through experimentally commissioning of industrial converter for induction motor control. Voltage and current waveforms of an induction motor powered by a frequency converter are analyzed during motor operation.

Consultations

Consultations are arranged via email.

Acquisition of Skills

Each student conducts laboratory exercises independently on his laboratory model which qualifies him to independently do commissioning of industrial frequency converters.

1. Course rules.
2. Induction machines: construction, physical principles, working principle.
3. Induction machines: mathematical model, torque-speed characteristics.
4. Speed control of induction motor.
5. V/f control, V/f control characteristics.
6. Induction motor speed control by using frequency converter.
7. Operating principle of AC/DC/AC frequency converter. Braking module.
8. Mid-term exam
9. Open and closed loop V/f control.
10. Tuning rules for P and PI controllers in closed loop V/f control structure.
11. Laboratory setup for the control of induction machines based on Siemens Sinamics G120 frequency converter.
12. Digital and analog inputs, digital, relay and analog outputs, encoder interface.
13. Specific functions of industrial frequency converters.
14. Integrated safety functions of industrial frequency converters.
15. Final exam