MODELING AND CONTROL OF ELECTROMECHANICAL SYSTEMS

Academic Year 2022/2023 - Teacher: Giuseppe SCARCELLA

Expected Learning Outcomes

The course aims to provide students with the fundamentals of modeling, operating principles and control of electrical and electromechanical energy conversion systems, the main basic knowledge and future developments. Experimental activities in laboratory sessions will receive much attention.

The knowledge acquired during the course will allow the knowledge of the operation of the most common electromechanical actuators and their control methods.

Knowledge and understanding

The student will acquire the knowledge of the operating principles and the main control methods of electrical machines. The main applications will be related to the fields of automation, electrical and electronic engineering.

Ability to apply knowledge and understanding

At the end of the course, students will have the necessary skills to analyze an electromechanical system, identifying its main sections and functions. Students will have the skills necessary for the characterization of systems and processes and for the design of electromechanical systems, with particular reference to modeling and control.

Autonomy of judgment

Students will acquire independent judgment for an accurate analysis of electromechanical systems, these skills will also be refined through experimental activities carried out in the laboratory.

Communication skills

The student will strengthen the technical language of electrical energy engineering with the aim of being able to adequately present himself to the world of work with adequate skills and an adequate technical profile. The ability to work in groups will be refined through the experimental experiences in the laboratory carried out in small groups. The drafting of the laboratory report and/or the oral exam will allow students to refine technical language and communication skills.

Learning skills

The student will be able to autonomously expand their knowledge on electromechanical conversion by deepening reference texts and papers in specialized scientific journals. The results of learning the concepts of the course are the knowledge of the operation of the most common electromechanical actuators and their most common control modes.

Course Structure

The training objectives are linked both to the acquisition of new knowledge, therefore frontal lessons as teaching method and tutorials to include the ability to apply the acquired knowledge through computer and/or laboratory exercises.

Required Prerequisites

Knowledge of the basic concepts of physics and electronics.

 

Attendance of Lessons

Student attendance, at University or in a remote way, is not mandatory but it is recommended. Remember that to achieve an optimum result, the student is required to attend at least 70% of the course lessons.

Detailed Course Content

The objective of this course is modeling and control the electromechanical systems (mainly rotating electrical machines: conventional and special) used in the conversion of electrical in mechanical energy and vice-versa. The course will give basic and advanced elements of two fields of the electrical engineering area taught in the courses of Electrical Machines and Electrical Drives Emphasis is placed on electromagnetic rotating machinery, by means of which the bulk of this energy conversion takes place. However, the techniques developed are generally applicable to electrical machines, renewable energy conversion and to a wide range of additional devices including linear machines, actuators, and sensors.

Although not an electromechanical-energy-conversion device, the transformer is an important component to understand the overall energy-conversion process that uses magnetic field. The models developed for transformers analysis form the basis for the ensuing discussion of rotating electric machinery. Finally Generalized Theory and Space Vector Theory are introduced to better explain Vector Control of AC Machines.

Summary of the course program

First part: Electromechanical systems.

Energy balance and conservative systems: determination of electromagnetic forces and torques. Power: active, reactive and apparent power. Three-phase systems. General information on electrical machines: materials, losses, efficiency, thermal behavior. Transformer: principle of operation, equivalent circuit, no-load and short-circuit tests; HF transformers. Asynchronous machine: MMF of distributed windings and equations, pole pairs, equivalent circuit, slip, electromagnetic torque.

Second part: Rotating machines.

Asynchronous machine: no-load and locked-rotor tests, starting, single-phase induction motors. Power Electronics: Rectifiers, Choppers. Converters for DC and AC electrical machines. Control of electromechanical systems: Electrical drives. DC servo-machines: commutator action, load operation, DC motors, shunt excitation generators, series excitation motors. Digital modulation techniques: PWM, space vector. VSI and CSI. DC and AC motor drives: Scalar control. Current control. Constant V by f control. Vector Control of asynchronous machines: IFOC, DFOC: VI, I-omega, I-theta. Synchronous machine: equivalent circuit, load angle, synchronous and reluctance torque.

Third part: Special machines, SMART-GRIDs, MICRO-GRIDs.

Special synchronous machines: Permanent Magnet (PM) motors, Synchronous Reluctance (SyncRel) motors, stepper motors, switched reluctance motors, Brushless DC motors. Vector control of synchronous and PM machines. Universal motors. Stepper motors. Switched reluctance motor control. Distributed and renewable energy generation. Drives for electric traction, electric and hybrid vehicles.

Textbook Information

  • A.E. Fitzgerarld: “Electric Machinery”, Mc Graw Hill.

  • P. Krause: “Analisys of Elelectrical Machines”, IEEE Press.

  • N. Mohan: "Power Electronics", Hoeply.

  • B. Bose: “Power Electronics and Variable Frequency Drives”, IEEE Press. 

  • T. Wildi: “Electrical Machines, Drives and Power Systems”, Pearson Prentice Hall.

Course Planning

 SubjectsText References
1Modeling. Fundamentals of electrotechnical basic principles.B. Bose “Power Electronics and Variable Frequency Drives”, IEEE Press.
2Electrical machines.A.E. Fitzgerarld: “Electric Machinery”, Mc Graw Hill.
3Electrical drives.T. Wildi: “Electrical Machines, Drives and Power Systems”, Pearson Prentice Hall.

Learning Assessment

Learning Assessment Procedures

Exams: oral tests. 

Learning assessment may also be carried out on line, should the conditions require it.

 

Examples of frequently asked questions and / or exercises

Characteristic and working principles of most common electrical machines: DC, Induction, Synchronous, Stepper, Switched Reluctance.

Generalized Theory.

Scalar and Vector Control. 

 

The teacher is also available for on line reception meetings.

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